Land Management [1 ed.] 9781620814604, 9781620814215

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Copyright © 2012. Nova Science Publishers, Incorporated. All rights reserved.

Copyright © 2012. Nova Science Publishers, Incorporated. All rights reserved.

ENVIRONMENTAL REMEDIATION TECHNOLOGIES, REGULATIONS AND SAFETY

Copyright © 2012. Nova Science Publishers, Incorporated. All rights reserved.

LAND MANAGEMENT

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ENVIRONMENTAL REMEDIATION TECHNOLOGIES, REGULATIONS AND SAFETY

LAND MANAGEMENT

SURENDRA SUTHAR

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EDITOR

Nova Science Publishers, Inc. New York

Copyright © 2012 by Nova Science Publishers, Inc. All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted in any form or by any means: electronic, electrostatic, magnetic, tape, mechanical photocopying, recording or otherwise without the written permission of the Publisher. For permission to use material from this book please contact us: Telephone 631-231-7269; Fax 631-231-8175 Web Site: http://www.novapublishers.com NOTICE TO THE READER The Publisher has taken reasonable care in the preparation of this book, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained in this book. The Publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or in part, from the readers’ use of, or reliance upon, this material. Any parts of this book based on government reports are so indicated and copyright is claimed for those parts to the extent applicable to compilations of such works.

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Independent verification should be sought for any data, advice or recommendations contained in this book. In addition, no responsibility is assumed by the publisher for any injury and/or damage to persons or property arising from any methods, products, instructions, ideas or otherwise contained in this publication. This publication is designed to provide accurate and authoritative information with regard to the subject matter covered herein. It is sold with the clear understanding that the Publisher is not engaged in rendering legal or any other professional services. If legal or any other expert assistance is required, the services of a competent person should be sought. FROM A DECLARATION OF PARTICIPANTS JOINTLY ADOPTED BY A COMMITTEE OF THE AMERICAN BAR ASSOCIATION AND A COMMITTEE OF PUBLISHERS. Additional color graphics may be available in the e-book version of this book.

Library of Congress Cataloging-in-Publication Data

ISBN: 978-1-62081-460-4 (eBook)

Published by Nova Science Publishers, Inc. † New York

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This book is dedicated to my Parents and brother Rajendra Singh

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CONTENTS

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Preface

ix

Chapter 1

The UK Approach to Contaminated Land Management A. Bello-Dambatta and A. Akbar Javadi

Chapter 2

Application of Soil Water Assessment Tool (SWAT) in Watershed Management: A Case Study in a Tropical Agricultural Catchment of the Panama Canal Watershed J. S. Oestreicher

Chapter 3

Organic Amendments for Agriculture Land Restoration Practices Surendra Suthar, Sushma Singh and Pravin Mutiyar

Chapter 4

Comparative Effect of Composts and Vermicomposts on P-Mineralization in Lateritic Soil: Factors Affecting the Process P. Pramanik and G. K. Ghosh

Chapter 5

Chapter 6

Chapter 7

Sustainable Management of Land and People’s Forests in the Indian Eastern Himalaya: A C&I Approach G. Pangging, Kusum Arunachalam and A. Arunachalam Landscape Stability Evaluation by Landscape Geomorphologic Dynamics (LGD) Assessment: Planning and Managing Landscapes Selma Beatriz Pena and Maria Manuela Abreu Restoration and the Sustainable Use of Complex Landscapes: An Integrative Conceptual Model Roberto Lindig-Cisneros, Ian MacGregor-Fors, Rubén Ortega-Álvarez and Arnulfo Blanco-García

Chapter 8

Reclamation of Degraded Land through Forestry Practices Rajeev Pratap Singh, Sonu Singh, Anita Singh and Puneet Singh Chauhan

Chapter 9

Green Technology to Accelerate Ecosystem Development Process on Llmestone Mine Degraded Land Anuj Kumar Singh

1

21 39

55

69

79

113

125

145

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viii Contents

About Contributors 157

Index 159

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PREFACE The effect of anthropogenic activities relating to industrial and economic development has had a significant impact on the land resources. Concerns about land-use/cover changes, land resources service quality, land fertility; land degradation etc. emerged in the research agenda at global scale during last two to three decades with the realization that land quality influences all sectors of economic and social developments. Over the last few decades, numerous international programme under the auspices of the Land-Use and Land-Cover Change (LUCC) project of the International Geosphere-Biosphere Programme (IGBP) and International Human Dimensions Programme on Global Environmental Change (IHDP) have been launched by international forum in order to measure the causes of land-use change on quality of ecosystem service and human wellbeing. This edited volume examines the issues and approaches of land management and for that a wide range of topics has been covered in this book. The land contamination is a major environmental and infrastructural problem in industrialized countries as a result of both past and present industrial processes and waste disposal activities. In Chapter 1 the approach of UK in restoration of contaminated lands is discussed in details by authors. The UK contaminated land policy addresses the problem from two main perspectives: (i) the protection of human health and the environment perspective, and (ii) the spatial planning perspective. A major policy trend is addressing these two perspectives simultaneously, with the development of integrated contaminated land management and redevelopment policies. A third emerging perspective is that of sustainable management, in particular the need to consider the timing of any intervention and the future consequences of any particular solution in relation to sustainable criteria. Chapter 2 described the application of Soil and Water Assessment Tool (SWAT), a physically based semi-distributed simulation watershed model, in conservation and sustainable resource use planning, watershed management activities, and risk forecasting. A brilliant scholar from UQAM has discussed the issues of watershed management planning and conservation in Panama Canal Watershed (PCW). This chapter illustrates that how SWAT could potentially be a beneficial support tool for use in watershed management planning for sustainable agriculture-based regional development programmes. The modern synthetic chemical-based farming system considerably raised outputs and enabled new cultivation even in less than fifty years of modern farming; it has started showing many negative effects on ecosystem quality and human wellbeing. The depletion of soil organic matter in (SOM) chemical-based farming system is another issue of concern

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x

Surendra Suthar

because of its ability to provide conditions for plant growth, soil biota functioning, reduction of greenhouse gases, modification of pollutants and maintenance of soil physical condition. In Chapter 3 the issue of agriculture land restoration through organic inputs programme is discussed by authors by quoting a case study of land SOM improvements through organic amendment inputs. Chapter 4 illustrates the role of compost and vermicompost applications on dynamics of phosphorous mineralization in lateritic soils. It is important to discuss here that lateritic soils are typically low in nutrient content especially in phosphorus (P) and continuous fertilization is required to obtain desired crop yield. Results thus suggested that the application of organic amendments increase the level of available P content, acid phosphatase enzyme activity; microbial respiration and microbial biomass in lateritic soil after application of organic amendments. The criteria and indicators (C and I) have become a new revolution in assessing the sustainable forest management that has been a focal point in the forest principle of agenda 26 of Rio Earth summit. Chapter 5 is written on this accent where feasibility of C&I tool in sustainable management of land and people’s forests in the Indian eastern Himalaya is discussed in depth. Chapter 6 presents an interesting text on landscape stability evaluation using landscape geomorphologic dynamics (LGD) assessment system. LGD assessment has as its main goal determining landscape stability or instability in a specific geographical area, within a period of time t. Through this assessment, it is possible, according to the interaction between natural and cultural factors, to predict how the landscape will tend to evolve. In this chapter authors have demonstrated the application of LGD assessment tool in land stability measurement in Lisbon Metropolitan Area of Portugal. Considering non-urbanized landscapes, restoration has become necessary to recover biodiversity and ecosystem services. Conceptual models are common in restoration ecology and some have been greatly influential to the research agenda. Chapter 7 is written on restoration and the sustainable use of complex landscapes applying integrative conceptual models. In this work author shared their experiences with adaptive restoration program implemented at Nuevo San Juan hereafter, Michoacán (West-central México). Results thus suggested that land managers can incorporate social aspects (such as market forces or different views of nature) into the management of complex landscapes. Chapter 8 illustrates the significant causes and types of land degradation for possible sustainable restoration strategies using forestry practices and their potential benefits effects on environment. In this chapter author argued that agro-forestry and bio-energy plantation may be a cost effective and ecologically sound practice to solve the twofold problems: energy and land degradations. Although, agro-forestry is a sound practice but selection of tree species need to be made carefully in order to optimize the results of restoration programme. Chapter 9 discusses about implication of green technology inclusive of afforestation supplemented beneficial microbial inoculants and other effective approaches for restoration of limestone mined degraded land. In this chapter author shared the results of his experiments on restoration trials of degraded land in limestone mined area using ecosystem approaches. The chapters in this volume underwent formal peer-review process, and I would like to take this opportunity to thanks my colleagues for their expert comments to improve the text of chapters. I am also thankful to Prof. Girijesh Pant, Vice Chancellor, Doon University for his constant services of encouragement and inspirations. I am also thankful to my contributory

Preface

xi

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authors for kind cooperation and timely submission of their scholarly articles for this volume. I extend my gratitude towards my departmental colleagues for their support and assistance during completion of this editorial work. Nova Science Publishers has admirably put up with the duration on this project and I am greatly indebted to Ms Carra Feagaiga, Department of Acquisitions, Nova Science Publisher Inc for her continuous support. Thanks also go to production department for text formatting.

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In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 1

THE UK APPROACH TO CONTAMINATED LAND MANAGEMENT A. Bello-Dambatta* and A. Akbar Javadi College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, Devon, UK

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ABSTRACT Land contamination is a major environmental and infrastructural problem in industrialised countries as a result of both past and present industrial processes and waste disposal activities. In the UK increasingly more greenfields that should be preserved and protected are being threatened and lost to development, with over 1,100 ha of greenfields reported to have been lost to development each year since 1997 alone. The demand for housing and the associated development for infrastructure to support it are the main drivers for developing greenfields, although there are numerous derelict or contaminated sites that could be redeveloped for this purpose. The UK contaminated land policy addresses the problem from two main perspectives: (i) the protection of human health and the environment perspective, and (ii) the spatial planning perspective. A major policy trend is addressing these two perspectives simultaneously, with the development of integrated contaminated land management and redevelopment policies. A third emerging perspective is that of sustainable management, in particular the need to consider the timing of any intervention and the future consequences of any particular solution in relation to sustainable criteria. This paper discusses issues of land contamination in the UK, and the UK approach of managing land contamination.

1. INTRODUCTION Land contamination is a major environmental and infrastructural problem in industrialised countries as a result of both past and present industrial processes and waste disposal activities. Land contamination could also occur naturally as part of the local geology *

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A. Bello-Dambatta and A. Akbar Javadi

or natural degredation. In the UK increasingly more greenfields1 that should be preserved and protected are being threatened and lost to development as a result of land contamination or dereliction, although there are numerous abandoned and derelict sites that could be sustainably regenerated and redeveloped for this purpose, with over 1,100 ha of UK greenfields have been lost to development each year since 1997 alone (CPRE, 2008). Contaminated lands not only cause loss of valuable land for food and housing but pose significant potential risks to human health and other receptors like water resources, ecosystems and infrastructure. Contaminants in land could affect human health through various exposure pathways such as inhalation of air, ingestion of food or dermal contact. These could be present in solid, liquid or gas phases, and may be physical, chemical or biological (Young et al., 1997). Although rare, increased levels of illnesses have been observed on people living on or near lands affected by contamination – such as organ damage (BBC 2001), birth deformities (BBC, 2009; Beck, 1979) and cancers (Hansen et al., 1997). Contaminants in soil can also pollute valuable water resources such as surface waters and groundwater aquifers (Powell et al 2003, Ford and Tellam, 1994), ecological systems and habitats (Smith et al 2005), and pose other hazards such as fires and explosions on property (Brown and Maunder, 1994; Harber and Forth, 2002; Young et al., 1997). Land is made up of soil and groundwater which are both finite resources because they form and regenerate on geological timescales. Soil covers most of the earth's land surface, varying in depth from a few centimetres to several meters. Healthy soils interacts with air to maintain the balance of essential gases and regulate the drainage and flow of groundwater, thereby acting as a filter of contaminants and a natural flood defence. There are therefore vital links between the soil, air and groundwater; with soil acting as a buffer system and the link between these resources. Soil is also a large natural store of carbon, with UK soils alone containing around 10 billion tones. The loss of this is estimated to create emissions equivalent to more than 50 times the UK’s current annual greenhouse gas emissions. Soil will therefore play a vital role in the fight against climate change (DEFRA, 2009). For the soil to perform these functions it must be healthy and managed effectively and sustainably. Unfortunately soil is a non-renewable resource as it can take up to hundreds or thousands of years to form through the different geologic processes and as such needs to be protected and preserved. Although evidence suggests that most sources of soil contamination are now suitably controlled, continued diffuse (non-point source) pollution2 from atmospheric depositions, leaching and run-off is an area of growing concern (EA, 2009). Diffuse pollution remains the main source of pollution of controlled water resources. Controlled waters comprise of all estuaries; surface waters like streams, rivers and lakes; groundwater resources; and territorial waters3. Groundwater is the largest source of fresh water supply for which many people around the world depend. About 30 percent of this groundwater supply is bound up in ice and snow, with only about 0.2 percent available as freshwater in lakes and river. This freshwater supply is the primary source of drinking water for billions of people around the world. In the UK for example, it is a third of the total drinking water supply in England and Wales, and in parts of the South East of England the only source of drinking water (EA, 2007). 1

Greenfields are previously undeveloped land. Diffuse pollution occurs when the sources of the contamination are not known, and could arise from many different sources. 3 Territorial waters are coastal waters up to three nautical miles from shore. 2

The UK Approach to Contaminated Land Management

3

Groundwater is formed by the water cycle (Figure 1) when rainwater infiltrates into the sub-surface and is stored in soil pores and permeable geologic formations known as aquifers. This eventually flows to the surface naturally as surface water, thereby maintaining fresh water habitats. As groundwater can be a long-term water reservoir where the natural water cycle takes anything from days to millennia to complete, it is exposed to potential contamination by pollutants leaching and/or running-off from degraded or contaminated soil. Over two thirds of the groundwater in the UK is at risk from diffuse pollution, with pollutants from fertilisers, manure, pesticides, oil and fuel comprising the main sources of groundwater contamination (EA, 2007). Grounwater is particularly vulnerable to diffuse pollution, which can take decades or centuries to recover because most chemicals degrade very slowly and groundwater is flushed through at a very slow rate. It is therefore a lot easier technically and more cost-effective to deal with point-source contamination, i.e. dealing with contamination in soil before the contaminants pollute water resources.

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2. EXTENT OF LAND CONTAMINATION Various national estimates have been made of how much contaminated land there is, which has varied considerably over the years as definitions and contexts evolved (Martin, 2002). The UK Environment Agency (EA) estimate there may be as many as 200,000 ha affected by contamination in England and Wales alone (EA, 2001) representing between 0.4 and 0.8 percent of the total UK land area (Young et al., 1997). Between five and 20 percent of these are thought to require action to ensure that unacceptable risks to human health and the environment are minimized or eliminated (EA 2002). Conservative estimates say it will take between £20 – 40 billion to clean up and return these lands to beneficial use (Watson, 1993). The figure is significantly increasing with the identification of more contamination. However, estimates of the extent of land contamination are often based on different definitions and terms which are not only fundamentally but technically different and therefore need to be viewed with caution (Pollard et al., 2001). For example, the term brownfield4 is often used interchangeably with contaminated land, although current UK legislation does not refer to it. Even terms such as derelict land, Previously Developed Land (PDL), and land affected by contamination, that have been clearly defined are also often used interchangeably although they are all technically quiet different (Figure 2). Average national estimates of European Environment Agency (EEA) member countries show that on average approximately eight percent of the member country lands are contaminated and need to be remedied (EA, 2007). However this figure needs to be taken with caution as there is no commonly accepted definition of contaminated land between member states (Carlon et al., 2009), and different countries have different definitions, legislations and priorities due to differences in extent and perception of the problem, and political and socio-economic backgrounds (Pollard et al., 2001). However although the estimate is affected by lack of a common definition, it still correctly reflects the magnitude of the problem (Carlon et al., 2009). Relatively little quantitative knowledge exists on the extent of the global scale of the problem, nevertheless there is little reason to believe that the situation is markedly different in other industrialized countries (Bridges et al., 2006). 4

A brownfield land is a previously developed land that could be vacant, derelict and / or contaminated.

4

A. Bello-Dambatta and A. Akbar Javadi

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Figure 1. The water cycle (Buchanan and Buddemeier 2005).

The management of contaminated land is presently about two percent of the overall EEA member country management expenditure, with average annual expenditure of 12 EUR per capita (Figure 3). Although the cost of the same clean-up solution can vary by several orders of magnitude across member states, the cost per site is estimated to be on average between 19 500 and 73 500 EUR, with the total cost of remediated sites approximately 28 billion EUR (Carlon et al., 2009). The EEA predict the number of identified contaminated sites to increase by 50 percent by the year 2025 due to increased level of awareness and commitment to the identification and characterisation of these lands (EEA, 2007). To date over 80 000 sites have been cleaned up across the EEA member countries (Figure 4), and there still remains approximately 250 000 identified sites requiring clean up (EEA, 2007).

3. CONTAMINATED LAND POLICY: A UK PERSPECTIVE Environmental policy in the UK has evolved substantially over the last decades both in domestic terms and as a response to European Community (EC) policy developments to ensure that it is not only relevant but proportional (Henton et al., 1993). In the early days land contamination was merely costed for in the purchase of land for redevelopment (Young et al 1997). Both government and public attitudes changed after a few high profile incidents like the Love Canal disaster (Beck, 1979) and the Loscoe bungalow demolition from landfill gas (Young et al., 1997). Contaminated land incidents then began to be perceived as very few and extremely severe incidents, with poorly understood but possibly disastrous consequences for human health (Vegter, 2001). Policy became more conservative, aiming for maximum risk control (the principle of multi-functionality5).

5

The multi functionality principle requires cleaning standards to be sufficient for any land end-use.

The UK Approach to Contaminated Land Management

5

6

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Figure 2. Relationship between different definitions of contaminated land (Pollard et al 2001).

As experience with the management of contaminated land has grown, the perception of the problem has changed significantly. Current policy regard land contamination as a widespread infrastructural problem with varying degrees of intensity and significance, and that returning all lands affected by contamination to pre-industrial standard is not only unnecessary, but technically and economically unfeasible (Ferguson, 1998). As such current policy favours a risk based approach with clean-up standards based on site end-use. This focuses decision-making on areas where risks are unacceptable (Sheehan and Firth, 2008). In the UK contaminated land policy is mostly restricted to the legacy of historic contamination. New contamination is considered separately under more stringent regulations since it could have been prevented (the prevention principle7) (Vegter, 2001).

6

A derelict land is land that has become damaged from development and is beyond beneficial use without treatment. A PDL is that which is or has been occupied by certain permanent structure(s). Land affected by contamination is that which is known to contain harmful substances that do not meet the statutory requirements under the contaminated land regime. 7 The prevention principle requires the state of the environment should not get worse as a result of pollution that can be avoided. Further pollution of already polluted areas should be avoided. The principle also implies that accumulation of persistent substances in the environment should be stopped.

A. Bello-Dambatta and A. Akbar Javadi 3.5 3.0 2.5 2.0 1.5 1.0

Spain

Norway

FYR of …

Estonia

Sweden

Austria

Finland

Belgium

Switzerland

Slovakia

Romania

Bulgaria

Denmark

France

Netherla…

Hungary

Italy

0.0

Czech …

0.5 Croatia

Annual expenditures ( %0 of GDP)

6

Figure 3. Annual expenditure for the management of contaminated sites as o/o of GDP (EEA 2007).

1. Contaminated Land Legislation

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Contaminated land policy in the UK is set by the central government but enforced and regulated by local authorities (LA). The contaminated land policy is closely associated both technically and legislatively with issues of redevelopment, groundwater pollution prevention and control, waste management and industrial site decommissioning (Pollard et al 2001) and is dealt with through a number of regulations. These are8: 





8

The Contaminated Land Regime which is set out in Part IIA Environmental Protection Act 1990 (EPA). The regime sets out a joint regulatory role between LA and the EA to deal with the legacy of historical land contamination by identifying and remedying contaminated sites where there is an identifiable and unacceptable risk to human health or the wider environment. The Planning System which deals with existing contamination during redevelopment to ensure the land is fit for use. This is the primary means of dealing with contaminated land issues, as the majority of remediation is carried out during the redevelopment and regeneration cycle. The Part IIA definition of contaminated land still applies to management under the planning regime. The Buildings Regulations 1991 applies to new developments to protect both the buildings and their future occupants from the effects of land contamination. The Part IIA definition of contaminated land also applies to management under the building regime. In the case of both new buildings and redevelopment, enforcement is by the Local Planning Authorities (LPAs), rather than by LAs.

Part IIA EPA applies to Scotland and Northern Ireland too; however the principal regulator with regards Part IIA is the Scottish Environment Protection Agency (SEPA) and the Northern Ireland Environment Agency (NIEA) in Northern Ireland respectively, and equivalent agencies and consultants.

The UK Approach to Contaminated Land Management 





7

The Water Resources Act 1991 is used for the prevention and removal of pollution from controlled waters. This is useful in situations where there is historic contamination and Part IIA does not apply, for example where the contamination is contained within the relevant water body or in cases of diffuse pollution where contaminant sources cannot be identified. The EU Groundwater Directive is used for the protection of groundwater resources from discharges and disposals of substances. This regulation is implemented in the UK through the Groundwater Regulations 2009. The Environmental Permitting Regulations (EPR) is useful in situations where contamination has resulted from land subject to waste management license, as Part IIA will not normally apply. There is also a duty of care under EPR for the safe disposal, transport and storage of waste-by products from remediation.

Number of  Remediated Sites Estimated nr of  Contaminated  Sites 

245.87

Number of  Identified  Potentially  Contaminated  Sites 

1823.6

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Estimated nr of  Potentially  Polluting Activity  Sites 

2965. 0.000

1000.000

2000.000 3000.000 4000.000 Number of sites in 2006 (x 1.000)

Figure 4. Status in investigation and clean-up of contaminated sites in Europe (EEA 2007).

2. Regulatory Roles and Responsibilities The risk based management policy is participatory with other government agencies and departments, and other stakeholders (Pollard et al., 2008), often involving statutory consultations and informal advice from various other government agencies, departments, LA and organizations, with each playing a complimentary role: (DEFRA, 2008): 

9

The Environment Agency (EA), which as the government’s principal adviser on the environment, is responsible for scientific and technical advice on contaminated land, for producing non-statutory technical guidance such as the CLEA9 model (EA,

CLEA – Contaminated Land Exposure Assessment.

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   

    

2004a) and the Model Procedures for the Management of Contaminated Land (EA, 2004b), and responsible for designated ‘special sites’10. The Department of Environment, Food and Rural Affairs (DEFRA) is responsible for contaminated land legislation and all associated policy. The Health Protection Agency (HPA) is the principal scientific and technical adviser with regards to health effects from toxic substances. The Food Standards Agency (FSA) is the principal scientific and technical adviser with regards to food issues resulting for land contamination. Local authorities (LA) are the principal regulators for contaminated land in their areas and are responsible for producing strategies for identification of contaminated land, for ensuring remediation takes place, for designation of special sites and for apportionment of liability. Local Planning Authorities (LPA) regulate the management of contaminated lands that is within the development or redevelopment cycle in their area. Regional Development Agencies (RDA) provide advice and guidance with regards to brownfield regeneration and sustainable development. Natural England provides advice with regards to the impacts of land contamination on ecosystems and the natural environment. English Heritage provides advice with regards to impacts of land contamination on the historic environment, elements of cultural heritage and historic landscapes. Guidance on addressing impacts on biodiversity is jointly provided by the EA, Natural England, English Heritage and organizations like the Royal Society for the Protection of Birds (RSPB) and the Centre for Ecology and Hydrology (CEH).

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3. Definition of Contaminated Land Although the prevention of new contamination is of critical importance, the focus of Part IIA legislation is on the substantial history and legacy of land contaminated, with new contamination dealt with separately (DEFRA, 2006). Even with historic contamination Part IIA normally only applies when no better solution is available, such as in situations where redevelopment has already taken place without adequate treatment or in sites that require urgent action because the risks are too great to await redevelopment (DEFRA, 2008). Contaminated land is statutorily defined in section 78A (2) Part IIA as: “any land which appears to the local authority in whose area it is situated to be in such a condition, by reason of substances in, on or under the land, that –  significant harm is being caused or there is a significant possibility of such harm being caused; or  Pollution of controlled waters is being, or is likely to be caused.”

10

A ‘special site’ is any contaminated land “which has been designated as such by virtue of section 78C(7) or 78D(6) of Part IIA EPA; and whose designation as such has not been terminated by the appropriate Agency under section 78Q(4) of Part IIA EPA”.

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Part IIA defines harm as “harm to the health of living organisms or other interference with the ecological systems of which they form part, and in the case of man, includes harm to his property”. Property includes buildings, infrastructure and could be in other forms such as crops, livestock, domesticated animals and wild animals subject to shooting or fishing rights. The term ‘significant’ is clarified in statutory guidance in relation to human health to include “death, disease, serious injury, genetic mutation, birth defects or impairment of reproductive functions; with similar guidance in relation to property, the environment and non-toxic effects on humans” (DEFRA, 2008). Controlled waters are defined in the Water Resources Act 1991 to comprise estuaries, inland waters, groundwater and territorial waters. The pollution of controlled waters is defined in section 78A (9) of the same Act as:

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“the entry into controlled waters of any poisonous, noxious or polluting matter or any solid waste matter.”

In relation to pollution of controlled waters, section 78A of Part IIA stipulates “controlled waters are ‘affected by’ contaminated land if (and only if) it appears to the enforcing authority11 that the contaminated land in question is ... in such a condition, by reason of substances in, on or under the land, that pollution of those waters is being, or is likely to be caused”. The definition of groundwater in relation to Part IIA is clarified in the Water Act 2003 to include water below the saturation zone. The definition does not include all land where groundwater contamination is present, but such lands may be relevant under other regimes (DEFRA 2006). This ensures that the contaminated land regime deals effectively with situations where contaminating substances have left the surface of land, and are contained in underground strata, but have not yet fully entered the saturation zone. Key to the definition of contaminated land in Part IIA is the pollutant-linkage concept (Figure 5) where contaminant sources must be in concentrations sufficient enough to pose a Significant Possibility of Significant Harm (SPOSH) to human health and other receptors, such as other natural resources like air and water resources, ecosystems and habitats, and property, which includes crops, livestock and buildings. A sound pathway (the linkage) must exist between contaminant source(s) and receptor(s) for risk(s) to exist, and therefore the land to be contaminated under Part IIA legislation. Other integral aspects of the risk based approach is the fitness for use12 principle which recognizes that different land uses require different soil quality, and for cleanup to therefore be proportional to site end-use, the protection of controlled waters, wider environmental and ecological protection and stewardship. The elements of the pollutant-linkage are defined in statutory guidance (Annex 3 of Part IIA EPA):  

11 12

A contaminant source is a substance which is in, on or under the land and which has the potential to cause harm or to cause pollution of controlled waters A receptor is either: a. Human beings, living organisms, group of living organisms, an ecological system or a piece of property ...; or b. Controlled waters which are being, or could be, polluted by a contaminant.

The EA in England and Wales, and SEPA in Scotland. Fitness for use principle aims at sufficiently reducing risks to human health and the environment as necessary to ensure the safe use or reuse of the land (CLARINET 2002a).

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A. Bello-Dambatta and A. Akbar Javadi 

A pathway is one or more routes or means by, or through, which a receptor: a. Is being exposed to, or affected by, a contaminant; or b. Could be so exposed or affected.

Risk to human health relates to the likelihood and magnitude of adverse effects from long term exposure (direct or indirect) of contaminants. Human health effects that are of concern include those related to chronic exposure including carcinogenic, mutagenic or toxic effects. Potential exposure pathways include direct dermal contact, inhalation, and direct accidental ingestion of contaminants or indirectly through the food chain or from water consumption. The most commonly encountered exposure pathway is ingestion. Risks to ecological systems include direct adverse effects on soil organisms, plants and above ground wild life, and indirect effects on soil functions (Carlon et al., 2009).

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4. The Risk-Based Approach The Part IIA definition uses a tiered risk-based approach to determine when land is contaminated, and how stringent remediation must be to return it to beneficial use. In general, risk assessment evaluates the probability of occurrence of adverse effects. If the adverse effects have occurred, the consequences are known as damage (CLARINET, 2002a). This is because in the vast majority of cases there is no appreciable risk, and a definition based on the mere presence of contaminants would cause large swathes of land to be caught unnecessarily. Taking contaminant concentrations in isolation of other risk factors is also not a good indicator of risk, as any given concentration may pose a markedly different level of risk depending on where it is and who/or what receptors may be affected (DEFRA, 2008). The risk based approach therefore targets contaminated lands where there is a possibility of harm occurring, as low levels of both natural and anthropogenic contaminants are present in most soils and there is little land that has not been subject to some degree of contamination in the UK, albeit by long-range aerial depositions (Pollard et al., 2001). The risk based approach is often challenging however as it is often hard to estimate risks precisely because of the site-specific nature of risks, the diversity and heterogeneity of contaminants, and the variability in knowledge of the effects of contaminants on receptors. It is also often difficult to distinguish between SPOSH and non-SPOSH, as decisions on whether risks constitute SPOSH are taken on a case-by-case basis taking into account toxicological information, and site specific variabilities (DEFRA, 2008). Despite these challenges however, the risk based approach is necessary in order to strike a balance between protecting human health and other resources, whilst minimizing unnecessary socio-economic and environmental burdens (DEFRA, 2008). Moreover not all of the impacts of land contamination are necessarily harmful. For example, an ecosystem could become dependent on some contamination conditions, and some contaminated sites could be part of a valued industrial heritage (CLARINTE, 2002a). The precautionary principle is applied in situations where: (i) SPOSH cannot be determined and there is a good reason to believe that it may occur; and (ii) the level of scientific uncertainty about the consequences or likelihood of the risk is such that best available scientific advice cannot assess the risk with sufficient confidence to inform decision-making (ILGRA, 2002). However good reason still needs to be demonstrated by

The UK Approach to Contaminated Land Management

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empirical evidence, expertise and/or sound theoretical explanation as to how SPOSH might occur. The purpose of the precautionary principle is to create an impetus for decision-making regardless of scientific uncertainty about risk, thereby preventing paralysis by analysis13 by removing excuses for inaction on the grounds of scientific uncertainty.

Ingesting dust

Rising vapours

Eating contaminated vegetables and soil adhering to vegetables

Tracking back of soil/dust from garden into home

Skin contact with dust

Skin contact with soil

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Rising vapours

Windblown dust

Plant uptake

Migration of contamination

Exposure Pathways Route

Inhaling outdoor dusts and vapours

Ingesting soil

Inhaling indoor dusts and vapours

Route

1

Ingestion of soil

6

Dermal Contact with household dust

2

Ingestion of household dust

7

Inhalation of fugitive soil dust

3

Ingestion of contaminated vegetables

8

Inhalation of fugitive household dust

4

Ingestion of soil attached to vegetables

9

Inhalation of vapours outside

5

Dermal contact with soil

Inhalation of vapours inside

10

Inhalation of vapours inside

Figure 5. An illustration of the potential human exposure pathways (DEFRA 2002).

5. Other Policy Drivers Apart from human health and environmental protection, there are other key drivers for contaminated land management policy. The demand for housing and the associated development for infrastructure to support it are the main drivers for developing greenfields (DEFRA, 2009), although there are numerous derelict or contaminated sites (brownfield) that could be redeveloped for this purpose14. The UK contaminated land policy addresses the problem from two main perspectives: (i) the protection of human health and the environment perspective; and (ii) the spatial planning perspective. A major policy trend is addressing these two perspectives simultaneously, with the development of integrated contaminated land management and redevelopment policies (Carlon et al., 2009). The conservation of land as a natural resource has led to policies that favour the redevelopment of brownfield, which is seen as a sustainable land use strategy. As part of this, 13 14

Paralysis by analysis occurs when an outcome for a decision is never reached due to over analysing. The lack of a common definition of brownfield has made quantifying the scale and extent of it difficult.

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A. Bello-Dambatta and A. Akbar Javadi

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the UK government has a brownfield initiative, which encourages ways of responsibly dealing with increasing land use pressures by regenerating vacant or derelict PDLs in an effort to curb greenfield consumption (Figure 6). This enables the recycling of more PDL than would otherwise be the case, increasing the ability to make beneficial use of the land (DEFRA, 2006). The governments target of 60 percent all new development to be on PDL under the brownfield initiative has been met eight years ahead of target (Figure 7). The creation of brownfield continues however, and some rehabilitation has not been successful, leading to return of the land to derelict or underused state (CLARINET, 2002a). A third emerging perspective is that of the sustainable management of contaminated land, in particular the need to consider the timing of any intervention and the future consequences of any particular solution in relation to at least economic, environmental and social criteria (Figure 8). The presence of extensive areas of contaminated or derelict land is one of the main challenges of sustainable land use, posing potential threats to achieving the governments targets for sustainable development (CLARINET, 2002a). The sustainable management of contaminated land is ‘the practice of demonstrating, in terms of economic, environmental and social indicators, that an acceptable balance exists between the effects of undertaking the remediation activities and the benefits the same activities will deliver’(Bardos et al., 2009). Sustainable management of contaminated land therefore aims to find a positive overall solution that will achieve multiple gains and minimize regrettable losses (Gibsons et al., 2005). This supports the government’s goal of sustainable development by helping the conservation of land as a valuable natural resource, reducing the pressure on greenfield development and preventing the spread of pollution (CLARINET, 2002a). In the UK sustainability issues with respect to soil quality are addressed through a combination of policy, regulatory, voluntary and technological instruments, including (Pollard et al., 2004): i. Bringing land back into early beneficial use. ii. Reducing pressure on greenfield sites and the pollution of groundwater resources, thus conserving agricultural land and natural habitats. iii. Adoption of a suitable-for-use approach towards land remediation. iv. The efficient use of resources to tackle issues of highest risk at priority sites. v. Prioritizing remedial action so as to address the worst risks first in relation to the use of the land concerned. vi. The application of sustainable remediation technologies that conserve land and resources. vii. Development and maintenance of new partnerships and from key stakeholders with agreements on a common research and practice agenda. viii. The consideration of types of sources of soil pollution over the long term. ix. The development of monitoring systems that allows early detection of adverse soil, water and ecosystems changes. x. The distribution of impacts from land contamination on communities.

The UK Approach to Contaminated Land Management

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4. CONTAMINATED LAND MANAGEMENT PROCESS The effective management of contaminated land requires the integration of vast multidisciplinary knowledge bases into a coherent decision-making framework, taking into account the range of contexts in which decision have to be made, including complying with the relevant legislative framework, accounting for total operating costs and benefits, and addressing issues of environmental impacts, sustainability, protection of other resources, and importantly the prevention of further and/or future contamination (Bardos, 2001). Land contamination also often involves different mediums (soil, groundwater, surface water). The management process therefore typically involves multi agency regulation and multidisciplinary expertise, with each discipline involved in interpreting discipline specific information for decision-making (Bardos et al., 2001). The contaminated land management process is complex and is typically undertaken using a phased approach (Table 1) with explicit considerations of risk at each phase of the decisionmaking process (Hester and Harrison, 1997). With costs increasing at each stage of the management process, site investigation is a critical stage for decision-making, as it is the stage where the key decision is made as to whether the site is contaminated and if so whether the contamination is sufficient enough to warrant remediation. The cost of site assessment stage is reported to be is in most cases less than five percent of the overall project costs and in many cases may not even exceed one percent (Genske, 2003). The importance of a thorough site investigation and assessment cannot be over emphasized as it could potentially prevent costly and unnecessary remedial action. Although each site is unique and requires a site specific solution, many of the key decisions are similar in structure. As a result many countries have developed generic national frameworks that integrate the key management decision-making processes (Bardos et al., 2001). The EA has developed a comprehensive technical framework for applying risk management to contaminated land (EA, 2004b). This sets out a structured framework for assessment and decision-making within government’s policy and statutory requirements that could be adapted to apply to a range of management contexts. The framework uses a tiered risk based assessment approach, with each incremental tier involving increasing detail and complexity. These tiers are preliminary risk assessment, generic quantitative risk assessment and detailed quantitative risk assessment (DEFRA, 2008). 



Preliminary (qualitative) risk assessment is undertaken to develop a site conceptual model based on information collected from desk study and site investigation phases. The conceptual model is used for identifying pollutant-linkages and is updated as more information becomes available. If a pollutant-linkage is found, then it may be necessary to proceed to the quantitative risk assessment or remedial action. If more than one linkage is found, it will need to be separately assessed and dealt with. Although professional judgment is used for assessment, decisions will still need to be justified both scientifically and technically. Generic quantitative risk assessment involves comparing contaminant concentrations with Generic Assessment Criteria (GAC) values. GAC values are generalized assessment criteria that are applicable to a wide range of soil types, site conditions

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A. Bello-Dambatta and A. Akbar Javadi

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

(geology, hydrogeology, hydrology etc) and land use types. Although not legally binding, the EA and DEFRA Soil Guideline Values15 (SGV) and the drinking water standards are used as GAC values for assessing risks to human health from soil contaminants and controlled waters respectively. Most practitioners still use withdrawn values such as the Inter-Departmental Committee on the Redevelopment of Contaminated Land (ICRCL) or the Dutch values rather than calculate SGV for unpublished contaminants, posing potential human health financial implications as they are not suitable for assessing the “significant possibility of significant harm to human health” in the context of the current contaminated land management regime (DEFRA, 2002). The Land Quality Management Ltd (LQM) and the Chartered Institute of Environmental Health have published GAC values for extended range of contaminants that is in line with the current contaminated land statutory regime and associated policy. These values are a reliable alternative to calculating values for contaminants with no SGV. Detailed quantitative risk assessment is undertaken to determine SPOSH using site specific data. It may be used as the sole means of assessing risks or in situations where the outcomes of the preliminary or generic risk assessment are not adequate. A software model or support tool is normally used for estimating and evaluating risk. The key objective will be to establish a threshold limit for each contaminant of concern, a remedial target. This is the concentration limit below which the contaminant will not pose a potential risk to receptor(s).

16

Figure 6. Soil loss to development in England, 1994 to 2006 (EA 2006).

15

Soil Guideline Values (SGVs) are DEFRA’s scientifically-based GAC values for evaluating long-term risks to human health from chemical contaminants in soils. 16 1999 data incomplete for absolute amounts.

The UK Approach to Contaminated Land Management

Redevelopment

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Figure 7. Land recycling 1990-2008 (DEFRA 2009).

15

17

Sustainable land use Priority based on the need to reuse the land

Priority based on present risk(s)

Environmental needs Figure 8. The different trends in contaminated land policy (CLARINET 2002a).

17

Include conversions. Up to 2002 conversion of existing buildings was estimated to add three percentage points, from 2003 the process of estimated has been elaborated.

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A. Bello-Dambatta and A. Akbar Javadi

Table 1. Systematic approach to contaminated land management: from identification to characterization, assessment and management Phase 1

Action Desk study

2

Preliminary site investigation Walk over survey

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3

4

Chemical sampling and analysis

5

Remediation

6

Site monitoring and aftercare

Description Information relevant to the whole management process is collected. Information collected may include geological maps and surveys, aerial photographs, historical information, land use, vegetation, water courses, oral evidence etc. Site visit to collect site-specific information and confirm information collected from desk study. Extent and nature of contamination are identified, ground conditions and vegetation established in desk study are confirmed, and evidence of impact of contamination is established. Information from all previous stages is assessed and evaluated, and the findings are used for designing a sitespecific remediation strategy. Site is returned to beneficial use by either removing contaminants posing harm, treating the contaminants to reduce or eliminate harm or containing the contaminants by isolating them. To ensure remediation is effective and management objectives have been fulfilled. Ongoing site monitoring may sometimes be necessary in cases where some level of contamination remain after remediation

Preliminary risk assessment often involves direct observation of the effects or consequences of the existence of a hazard, which could take the form of visible pollutants leaching into water or the observation of morbidity or death in livestock or crop. In many cases risk assessment is based on a prediction of the risk. This relies on a good understanding of site characteristics or modelling to estimate risks and how they might arise. The prediction of risk could introduce uncertainty in risk assessment however as:   

There may be incomplete understanding of risks, or modelling may produce imperfect representation of the real world, and Sampling, analysis and other investigations may not provide an accurate reflection of the true or relevant characteristics of the site (EA, 2004).

If the outcome of risk assessment requires further action, a risk management strategy is developed and implemented. In many cases the practical objective of risk management is to reduce risks rather than to eliminate them as total containment or removal of contaminants from complex and heterogeneous soil environment is rarely feasible (Bridges et al., 2006). Risk management is therefore a much broader process than the selection of remediation technologies, and includes all the aspects of developing and implementing a sustainable solution (Vegter, 2001). This involves remediation design and the appraisal and selection of

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appropriate remedial action(s), by ensuring that remediation is not only effective, sufficient and proportional to land end use, but carried out within the relevant legislative framework. Remediation is the corrective action of cleaning up contaminated sites by eliminating or reducing the contamination to an acceptable level (Carlon et al., 2009). The BATNEEC18 principle is applied to ensure the Best Available Technology (BAT) is used, while considering costs, effectiveness and other secondary factors such as environmental impacts and sustainability of the remediation technology used. Remediation is often designed for either the total or part removal of the contaminant source(s), breaking or changing the pathway to receptors or relocating receptors. Remediation technologies broadly fall into one of these categories (after Janikowski et al 1998 and Carlon et al., 2009): 



 

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

Excavation of the contaminated soil for disposal elsewhere, followed where necessary by replacement with clean material. Ex-situ19 technologies are applied to excavated soil and/ or extracted groundwater. Engineering systems including isolation or containment of the contaminated soil by covering it with a suitable thickness of clean, inert fill or hard cover. These could involve both In-situ20 and Ex-situ technologies. Treatment based approaches for destroying, removing, cleaning or immobilizing contaminants, and could include chemical, biological or physical processes. Site rehabilitation measures such as growing grass cover to bring back some utility to sites that cannot be treated or contained due to technical or economic reasons. Mixing the contaminated material with clean soil or sub-soil in order to reduce the maximum concentrations of contaminants to below the threshold trigger values.

The remediation technologies used for remedying contaminated sites strongly depend on several factors, including the nature, concentrations and physical states of pollutants present, the type of soil and specific aspects of the site itself (Rulkens et al., 1993). Remediation also requires consideration of other factors, including balancing inevitable trade-offs between economic, environmental, social and technical criteria with respect to set management objectives and regulatory requirements. Increasingly remediation strategies are moving from technology based approaches to integrated treatment systems (treatment trains) that focus on land use management and the use of emerging technologies such as natural attenuation and phytoremediation (James and Kovalick, 2002). Treatment trains are necessary in order to provide lower cost and more effective remediation solutions for complex sites (James and Kovalick, 2002). Remediation is also increasingly focusing more on in-situ, area wide approaches rather than the traditional ex-situ, site specific approaches. Emerging technologies usually require much longer clean up periods however, and need to be balanced with other management objectives. Experience has shown there is no universal practical solution, with each solution having its advantages and disadvantages depending of site conditions, the nature and extent of the contamination, regulatory requirements and remediation objectives (CLARINET 2002a). Doubts still exist over the efficacy of many remediation technologies (LHC 1994), and the 18

BATNEEC – Best Available Technology Not Entailing Excessive Costs. Ex-situ remediation is carried out above ground, and could be off-site. 20 In-situ remediation is carried out in place, i.e. without removing the contaminated media. 19

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A. Bello-Dambatta and A. Akbar Javadi

question remains as to whether remediation in itself is sustainable (CL:AIRE, 2007). Each of the currently available remediation technology has significant drawbacks either economically, environmentally, socially or technically. Additionally, the biological functioning of the soil is often impaired during the cleaning process because of destruction of the microbial system and soil structure (Janikowski et al., 1998).

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CONCLUSION Land contamination is a major environmental and infrastructural problem in industrial countries, with potential detrimental effects on human health, valuable water resources, sensitive ecological systems, property and infrastructure. The effective management of contaminated land typically involves multi-agency regulation and multidisciplinary expertise. This requires the integration of vast multidisciplinary knowledge bases into a coherent decision-making framework, within current regulatory framework(s). In considering the best course of action several factors must be taken into account such as site specific constraints, total operational costs and benefits, engineering feasibility, potential environmental impacts, sustainability and site monitoring and aftercare. Increasingly the goal of remediation is on the sustainable management of the contamination involving either full or partial treatment, isolation, or removal of contaminants on site. A solution with long-term aftercare may not be cost effective, and therefore economically unsustainable and possibly prohibitive, especially with cost often being the overriding factor in decision-making (Pollard et al 2004). It is also possible that a solution that appears suitable and is sufficient and proportional to land end-use may not be feasible technically or economically. A solution that takes short-term view of cost in lieu of longer-term financial and economic implications could result in a negative relationship between remediation costs and that of monitoring and aftercare (Pollard et al 2001). Sustainable management involves balancing inevitable trade-offs between competing economic, environmental and social criteria, with ideal (sustainable) solutions aiming to minimize total operational costs, minimize environmental impacts and maximize social benefits. The ideal is rarely achieved on the basis on scientific evidence alone, and increasingly decision-making techniques and Decision Analysis (DA) methods are used to support with balancing the inevitable trade-offs between decision criteria.

REFERENCES Bardos, P., Lazar, A. and Willenbrock (2009). A Review of Published Sustainability Indicator Sets: How applicable are they to contaminated land remediation indicator-set development? Sustainable Remediation Forum UK (SuRF-UK), (January 2010). BBC (2001). Chemical leak link to kidney damage. May 2001, (January 2010). BBC (2009). Families with birth defect battle. July 2009, (January 2010).

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Beck (2010). The Love Canal Tragedy. January 1979, EPA Journal, < http://www.epa.gov/ history/topics/lovecanal/01.htm> (May 2010). Bridges et al (2006). Risk-Informed Decision Making Applied to Coastal Systems: Sustainable Management of Flood Risks and the Environment. Risk Analysis. Brown, K.A. and Maunder, D.H. (1994). Exploitation of landfill gas: a UK perspective. Water Sci. Technol., 30, (12), 143-151. Carlon, C., Bruce, H. and Quercia, F. (2009). Contaminated Land: A Multi-Dimensional Problem. Decision Support Systems for Risk-based Management of Contaminated Sites, 2009, pp 1-23. CL:AIRE (2007). Uncovering the True Impacts of Remediation, Contaminated Land: Applications in read environments. < http://tinyurl.com/yz2wdgh> (January 2010). CLARINET (2002a). Sustainable Management of Contaminated Land, An Overview. (January 2010). CPRE, Green Belt loss a daily reality despite government pledges, May 2008 (March 2010). DEFRA (2006). Defra Circular 01/2006 Environmental Protection Act 1990: Part 2A Contaminated Land. Crown copyright 2006. DEFRA (2009). Safeguarding our Soils A Strategy for England. Crown copyright 2009. EA (2001). The state of the environment of England and Wales: the land. The Stationery Office Ltd, London, 181pp. EA (2002). Dealing with Contaminated Land in England. The Stationery Office Ltd, London, 40pp. EA (2004a). Model Procedures for the Management of Contaminated Land. (January 2010). EA (2007). The unseen threat to water quality: Diffuse water pollution in England and Wales report. Environment Agency. EA (2009a). The Environment Agency’s Position on Oil Pollution of Inland Waters. (March 2010). EEA (2007). Progress in management of contaminated sites. European Environment Agency (January 2010). Ferguson, C, C. (1998). Assessing Risks from Contaminated Sites: Policy and Practice in 16 European Countries. Land Contamination & Reclamation, 7 (2):33-54. Ford, M. andTellam, T. H. (1994). Source type and extent of inorganic contamination within the Birmingham urban aquifer system. UK. J. Hydro!. 156:101 - 135. Genske, D. (2003). Urban land: degradation, investigation, remediation. Springer Verlag, 333 pp. Gibson, R. B. and Hassan, S. (2005). Sustainability assessment: criteria and processes. Earthscan. 254pp. Harber and Forth 2002. Hansen, J, de Klerk, N. H., Musk, A. W. and Hobbs M. S.T (1998): Environmental Exposure to Crocidolite and Mesothelioma: Exposure-Response Relationships. Am. J. Respir. Crit. Care Med., 157(1):69 – 75. Henton, Patricia M. and Young, P. J. (1993). Contaminaed Land and Aquifer Protection. Water and Environment Journal, 7(5), 539-546. Hester, R. E. and Harrison, R. M. (Eds.) (1997). Contaminated land and its reclamation. Royal Society of Chemistry, 145pp. ILGRA (2002): The Precautionary Principle: Policy and Application. June 2002.

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James and Kovalick (2002). Jankowski, P., and Stasik, M. (1997). Spatial understanding and decision support system: A prototype for public GIS. Transactions in GIS, 2(1): 73. LHC (1994). Contaminated Land. London Hazards Ceneter Factsheet, (March 2010). Martin, J. C. (2002). A prototype knowledge-based system for the preliminary investigation of contaminated land. PhD Thesis, University of Durham, 2002. Pollard, S. J. T., Lythgo, M. and Duarte-Davidson, R. (2001). The Extent of Contaminated Land Problems and the Scientific Response. The Royal Society of Chemistry. Pollard, S. J. T., Brookes, A., Earl, N., Lowe, J., Kearney, T. and Nathanail, C. P. (2004). Integrating decision tools for the sustainable management of land contamination, Science of The Total Environment, 325(1-3): 15 - 28. Pollard, S. J. T., Davies, G. J., Coley, F. and Lemon, M. (2008). Better environmental decision making - Recent progress and future trends. Science of The Total Environment, 400( 1-3): 20 - 31. Powell, K. L., Taylor, R. G., Cronin, A. A., Barrett, M. H., Pedley S., Sellwood, J., Trowsdale, S. and Lerner, D. N. (2003): Microbial contamination of two urban sandstone aquifers in the UK. Water Research, 37(2): 339-352. Rulkens, W. H., Tichy, R. and Grotenhuis, J. T. C. (1998) Remediation of polluted soil and sediment: perspectives and failures. Water and Science Technology, 37(8), 27-35. Sheehan, P. and Firth, S. (2008). Client’s Guide to Contaminated Land Risk Assessment. THE LAND REMEDIATION YEARBOOK 2008,< http://tinyurl.com/yj5st3e> (January 2010). Smith, R., Pollard, S, J. T. and Nathanail, C, P. (2005). Assessing significant harm to terrestrial ecosystems from contaminated land. Soil Use & Management, 21(2): 527 – 540. Young, P. J., Pollard, S. and Crowcroft, P. (1997). Overview: Context, Calculating Risk and Using Consultants. Royal Society of Chemistry. Vegter, J. J. (2001). Sustainable Contaminated Land Management: a Risk-based Land Management Approach. Land Contamination & Reclamation, 9(1): 95-100. Watson, A. (1993). Britain's toxic legacy: The silence over contaminated land. Ecologist. 23(5): 174-178.

In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 2

APPLICATION OF SOIL WATER ASSESSMENT TOOL (SWAT) IN WATERSHED MANAGEMENT: A CASE STUDY IN A TROPICAL AGRICULTURAL CATCHMENT OF THE PANAMA CANAL WATERSHED J. S. Oestreicher McGill University, Department of Bioresource Engineering and School of Environment (at time research was conducted), Université du Québec à Montréal, Institut de sciences de l'environnement, Canada

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ABSTRACT The Panama Canal Watershed (PCW) provides water to operate the Canal, generate hydroelectricity, and supply water provisions to the local and metropolitan populations. With a maxed-out water budget, however, this region has little room to accommodate the possible effects of unsustainable land-use changes that threaten to alter water flows and timings. On the other hand, the water storage capacity of the canal reservoirs, necessary for water use during the dry season deficit, is compromised by sedimentation – the result of erosion and landslides on mismanaged lands. Given this context, tools must be developed to support conservation and sustainable resource use planning, watershed management activities, and risk forecasting. The Payment for Ecosystem Services (PES) option, which aspires to provide farmers with incentives to reduce erosion-causing activities, is among the most promising in situ policy tools for conservation and watershed management. The Soil and Water Assessment Tool (SWAT), a physically based semi-distributed simulation watershed model, is an instrument that can provide important information for watershed management in this context. To assess the ability of SWAT application for use in the Panama Canal Watershed (PCW), the model was calibrated and validated for streamflow and sediment yield in the 75 km2 pilot study area of the Caño Quebrado River subbasin, an area of burgeoning pineapple farms and with a history of cattle ranching. Two land cover change scenarios are simulated in order to assess the model’s ability to project the effects of land use policy changes on water and sediment yield. Overall, this study illustrates that SWAT could potentially be a beneficial support tool for use in watershed management planning.

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J. S. Oestreicher

1. INTRODUCTION The Central American Republic of Panama is best known for the Panama Canal, an economic pillar of the Panamanian and global economies. The canal, situated in the narrowest part of the isthmus, connects the Atlantic and Pacific Oceans and attests to the marvels of human engineering. In 2014, an expansion of the canal will be completed so as to accommodate larger freighters and so that Panama may maintain their monopoly as the primary inter-oceanic passageway. The watershed surrounding the Panama Canal supplies freshwater used to transit ships, to generate hydroelectricity and to provide urban populations with potable water; yet sedimentation of reservoirs also threatens to reduce their water storage capacity. Water flows into canal reservoirs during the wet season (from May to December) and its storage is essential to ensuring that canal operations continue and that local population needs are met throughout the dry season. However, due to both natural and human-induced sedimentation of the reservoirs (PMCC 1999), the Autoridad del Canal de Panamá (Panama Canal Authority, ACP) must continually dredge sediment to maintain a sufficient reservoir depth. In light of this situation, reducing sedimentation, as well as closely monitoring water yield and flow timings, is a primary concern of the ACP and other political bodies.

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The Tinajones, Caño Quebrado, and Los Hules River Basin: the epicenter of pineapple production in the Panama Canal Watershed

Figure 1. a) The republic of Panama. The Panama Canal Watershed (PCW) is demarcated in grey; b) Location of the Tinajones, Caño Quebrado, and Los Hules River basins (TCH) within the PCW. Data taken from the Balboa (BAL) and Gamboa (GAM) weather stations and the rain gauges Zanguenga (ZAN), Cerro Cama (CCA), and El Chorro (CHR) were used as SWAT input; c) the TCH subbasins and their primary rivers. The Caño Quebrado gauge used for model calibration is indicated.

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Application of Soil Water Assessment Tool (SWAT) in Watershed Management

23

Although land cover transitions (i.e., deforestation) in the PCW has stabilized – most titled land was deforested in the 1950’s and is currently used for livestock grazing while most remaining forest stands are protected (PMCC 1999) –, one specific area has caught the attention of watershed monitors due to a notable land transition: The Tinajones, Caño Quebrado, and Los Hules River (TCH) basins (Figure 1). TCH basins are located in the central region of the PCW, have a total catchment area of 154 km2 (about 4.5% of the greater watershed area) and directly outlet into the primary Canal reservoir, Lago Gatun. Since 2001, pineapple plantations have been rapidly expanding, turning the TCH area into a hotspot for pineapple culture. In fact, in the last eight years the area converted to pineapple plantations has roughly tripled and it is projected to continue to increase at similar rates (Martez and Vergara April 2004). The increasing land area under pineapple cultivation has left many wondering what the long-term impacts of this expansion could be in terms of increased sediment generation and water flows. There are a total of 27 towns and hamlets in the area with a population of about 4100 (Marín and Yee 2004). Sixty-six percent of the population works in the agricultural sector (Marín and Yee 2004), many of whom work on pineapple plantations or in one of the three nearby pineapple packing plants. As in the rest of Panama, there exists a large inequality in land tenure; in fact, several of the plantation owners reside outside of the area, either in the nearby capital or other large urban centers. Also, due to the growing number of pineapple plantations and the increased need for labour, many workers have been contracted from other remote provinces, earning an average pay of about 3-4 US$ per day (IDIAP 2007). Soils in the area are principally fine clays or clay-loams of the Ultisol soil class and the Udult suborder (IDIAP 1996; USDA and NSCR 2005) – or Humic Acrisols of the FAO soil classification system (FAO and UNESCO 2003). Although, in general, high clay content soils are not particularly susceptible to erosion, soils of the area are assumed to be of kaolinitic clay origin with clayey B horizons which are structurally unstable, prone to crusting – which has been observed in TCH during the dry season –, and are easily compacted by cultivation (Lal 1990). Such changes in soil properties and structure can lead to high runoff rates and are important features in assessing the vulnerability of soils to erosion. The climate is characteristic of the sub-humid tropics, with an average annual rainfall of 1887 mm (AED 2004b) and two distinct seasons: the wet season – May to December – and the dry season – January to April. Precipitation is most intense in October, while monthly average precipitation in February and March commonly approaches zero. Average annual temperatures are 26ºC, however, diurnal temperatures range from 33ºC to 23ºC; daily average temperatures do not significantly fluctuate seasonally. Seventy five percent of the area is less than 100 meters above sea level, while some of the highest points surpass 200 meters. While geography and climate make the region ideal for pineapple cultivation, other prevailing issues, in addition to unstable soils, make the area prone to erosion. Intense seasonality means extreme dry seasons, which can cause cracking on degraded soils and lead to high surface runoff rates. Additionally, heavy storms in the wet season can expose soils with no vegetative cover to rainfall impact. Pineapple production in the TCH basins is intense and farmers do not generally employ soil conservation (erosion prevention) techniques (Martez and Vergara 2004). In 2004, Martez and Vergara (2004) documented erosion on all pineapple farms in TCH, classifying 33% of cultivated land as severely eroded. According to their survey, all pineapple farmers (with the exception of one) identified erosion and its severity as an important issue.

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Considering that soils in the area are susceptible to degradation and that the landscape topography of the area is largely sloping (average slope 8%, maximum 49%), reducing erosion in the area will largely hinge on crop cover, cropping patterns and planting in appropriate areas. Developing watershed management strategies in the PCW would benefit from an analysis of the advantages of changing land cover and land use (i.e., using different soil conservation techniques) in the TCH. This would allow watershed managers to pinpoint methods that are most effective at controlling and reducing erosion at the basin scale. A first step to achieving this will involve accurately modeling sediment and water yields in the current state of the watershed. The comparative advantages of different conservation options could then be examined and the extent to which sediment yields in the area are reduced could be estimated, allowing managers to identify the most effective techniques and plan conservation strategies.

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2. PAYMENT FOR ECOSYSTEM SERVICES The economic costs of increased reservoir sedimentation are potentially high1, so identifying the causes of unsustainable practices and ensuring reductions in erosion-causing activities within the PCW is central to the continued economic success of Panama. The unsustainable management of pineapple farms in the TCH may be owing to a number of reasons: information on sustainable farming practices is rarely available and accessible, better practices are labour and asset intensive (preparing land for planting along contour lines or on terraces), no fiscal incentives or sanctions exist, among others (OIRSA 1999). Although a majority of pineapple farms in the area are large-scale commercial plantations (Martez and Vergara 2004) that may have access to resources (time, labour, information), there are also a number of small-scale pineapple farmers in the area that may not have similar access. Given these gaps, a program offering fiscal incentives for improved land-management practices for large and small-scale farms in combination with technical support could be a key to reducing sedimentation in the Canal and sustaining water flows and timings in the long-term. A promising conservation program, payment for ecosystem services, is expected to be implemented in the TCH basins and will attempt to provide both pastoralists and farmers with incentives to use soil conservation techniques. The concept of payment for ecosystem services merges markets with ecosystem services to provide economic incentives for resource conservation. The conservation mechanism functions in a manner whereby beneficiaries of ecosystem services remunerate the service providers, in this case pineapple growers and ranchers, for conserving soil and water resources (MEA 2005). In the PCW, regulating and provisioning services, such as flow timings, erosion control and fresh water provisions (MEA 2005), are vital services that could be conserved via a payment for ecosystem services mechanism. Service buyers, such as the ACP or global users of the canal, could pay pastoralists and pineapple farmers for adopting management practices that reduce erosion. Decreased erosion would reduce the amount the ACP spends on dredging operations, thereby freeing up funds that could be invested in sustainable agriculture. The benefits of the erosionprevention measures should outweigh the costs of dredging operations and payments must 1

In addition, another concern is the maintenance of water yields and flow timings, services that are threatened by climate change as well as land degradation due to unsustainable cattle grazing or agricultural practices.

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surpass the opportunity cost of land. Other versions of this scenario can be explored, for example water consumers paying farmers to reduce fertilizer use to improve water quality or the government providing incentives to reforest land to improve dry season flow and reduce erosion2, and many others. (See Fotos et al., 2007 for a detailed assessment of demand for ecosystem services in the PCW). In the context of the expanding pineapple culture in the TCH basins and the threat of increasing sedimentation of canal reservoirs, sustainable agroecosystems are a necessity and are attainable; yet the information, resources, and incentives must be simultaneously provided to farmers and ranchers in order for such changes to occur and solidify. Moreover, a practical tool is needed to predict the effects of the current pineapple cultivation practices and to simulate the potential impact of erosion prevention measures or land cover changes; this will support the incentive-based conservation method which may help reduce sediment yield in the TCH basins.

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3. THE SOIL AND WATER ASSESSMENT TOOL Accurate prediction of watershed-scale sediment production and the effects of erosionprevention activities will be a paramount factor for the successful implementation of the Payment for Ecosystem Services pilot project. To assist in the planning and implementation of a such a program, the hydrological model SWAT (Soil and Water Assessment Tool) (Arnold et al. 1998) is being adapted to simulate the effects of different management practice scenarios on sediment and water yields in the TCH basins. SWAT is a physically based semidistributed simulation watershed model that runs on a daily time-step. It relies on climatic, soil property, topographical, vegetative and land management input data to predict the impacts of land management practices on water, sediment and agricultural chemical yields in large watersheds over long periods of time. SWAT is a powerful tool that has been used as a support system for environmental decision and policy making in the tropics. For example, SWAT was successfully used to implement an inter-state water allocation program in India to conserve water resources (Singh and Gosain 2007). Schuol et al. (2007) used SWAT to identify regions of potential water scarcity in West Africa, providing a regional perspective of water flows. SWAT has also been applied, with acceptable performance, to model the effects of hypothetical land-use change scenarios (primarily deforestation and reforestation of croplands) on flow, sediment, and nutrient yields in Honduras (Rivera and Martinez 2003), Costa Rica (Benavides and Veenstra 2005), Brazil (Barsanti et al. 2003), Kenya (Jacobs et al. 2003b; Jacobs et al. 2003a), and China (Ouyand et al. 2007). The objective of this study is to calibrate and validate streamflow and sediment yield in the TCH and to simulate the effects of land-cover change scenarios using the Soil and Water Assessment Tool (SWAT). The results of this study will open the door for a theoretical discussion of SWAT’s ability to model other land covers, such as forest and pasture lands, 2

Evidence of reforestation restoring dry season flows is not universally accepted. In fact, there have been cases where reforestation decreases dry season flow, as eloquently detailed in Bruijnzeel (2004). Moreover, erosion reduction of forested lands will depend the management of the system (i.e. poorly managed forestry plantations or natural forested systems).

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and to assess the usefulness of this model in the context of watershed management in the PWC and the implementation of a PES program. This study contributes to the literature by applying SWAT to a tropical watershed with a large pineapple cultivation component.

4. METHODOLOGY

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Model Input Data SWAT input data may be divided into two general categories, spatial input, which includes physical landscape data such as topography, water body location, and land-use/landcover and soil maps, and temporal input, which includes climatic data used for model simulation and flow and sediment records used for model calibration and validation. Spatial data was modified with ArcGIS 9.2 and conforms to the Universal Transverse Mercator (UTM) coordinate system and the North American 1927 (NAD27) reference datum. Topographical features of the TCH area are represented by a grid-based 30-meter vertical resolution DEM, provided by ACP (2006), which was also used to generate a digital stream network. A land-cover map was generated from three map sources. Two vector maps of areas under pineapple cultivation, generated by the ACP from Landsat-7 images of June 2003 and October 2006, were overlaid with a third land-cover map of in the TCH area generated with Landsat-5 imagery from the year 2000. Land-cover in the third map resource was classified as urban, forest plantation, mature and secondary forests, pasture, and agriculture, Once the three maps were overlaid, land-cover was reclassified according to the following 5 categories: areas in pineapple cultivation (a) in 2003 only, (b) in 2003 and 2006, and (c) in 2006 only, (d) pasture cover, and (e) forest cover, based upon the ANAM classification system (ANAM and ITTO 2003). Two national soil survey map sources were used to estimate soil input parameters. The most recent survey, performed by IDIAP (1996), was used to extract information on soil pH, organic matter content, trace metals and elements, nitrogen, phosphorus and potassium concentrations, and soil texture for the study region (IDIAP 1996). The second soil survey, performed by CATAPLAN (1970), provided information on soil depth and soil hydrologic group. Pedotransfer functions (PTFs), equations derived from statistical regression analyses of known soil properties, were used to approximate soil hydraulic characteristics based on soil texture (Saxton and Rawls 2006). Textural data was employed in the Soil and Water Characteristics model (Saxton and Rawls 2005), a program that calculates soil hydraulic properties based on equations derived from statistical correlations of known USDA soil data. Soil organic carbon content and the USLE soil erodibility factor (K) (Wischmeier et al. 1971) were estimated using equations provided by the SWAT user manual (Neitsch et al. 2002). All data was compiled into a single raster-based soil map using GIS software. Stream flow and suspended sediment, used for model calibration and validation, have been monitored daily since 2003 at one gauge station near the outlet of the Caño Quebrado 2 River (CQ1) (Figure 1). This monitoring station covers a drainage area of 67 km , which corresponds to 90% of the Caño Quebrado River basin, accounting for 42% of the entire study area. Baseflow at the CQ1 station was calculated with streamflow data from 2003 to

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2006, using a recession filter equation described by Nathan and McMahon (1990) and recommended by for use in SWAT (Neitsch et al. 2002). The filter may be passed through the dataset once forward, then backward, and then forward again. An average of the second and third passes through the filter was determined and used as an estimate of baseflow. Precipitation in the TCH basins is monitored daily at two stations and a third station is located just outside the western border (Figure 1). Daily precipitation at each station has been recorded for different time periods: Cerro Cama (CCA) has been monitored for 10 years, Zanguenga (ZAN) for 2.5 years, and El Chorro (CHR) has been monitored for 25 years. Data from all three stations was used for model simulations in SWAT. Other meteorological data required by SWAT for simulations, such as daily maximum and minimum temperature, solar radiation, relative humidity and wind speed, were generated using the WXGEN weather generator model (Sharpley and Williams 1990). WXGEN is a mathematical model that estimates daily climatic input through statistically generated data from at least 20 years of daily observed values. In the greater PCW, there are three stations that have more than 20 years of daily meteorological records available, two of which, Balboa (BAL) and Gamboa (GAM), are in close proximity to the TCH basins (Figure 1). GAM station, which is slightly closer to the TCH area, is located in a forested zone, while BAL is located in a semi-urban area. Land management practices, such as planting and harvest schedules, tillage practices, fertilizer applications etc., are required by SWAT when the effects of land management practices on physical processes are to be examined. Accurate simulation of these practices is important for studies that aim to simulate erosion and, if applicable, nutrient and agrochemical transport and water resource use. The land management practices performed by pineapple producers in TCH were incorporated into the SWAT model. Land management practice data was collected from IDIAP interviews (2007, unpublished) with 50 willing-toparticipate pineapple producers in the TCH region, representing approximately half of the pineapple producer population in the area. Data on more than 90 different plant species are available for SWAT plant growth and crop yield simulations including grasses, shrubs, trees, and most major commercial crop species such as corn, wheat, soy etc. The data necessary to simulate growth is stored in the SWAT default crop growth database but does not include information on the pineapple plant. Information necessary to simulate pineapple plant growth was, therefore, gathered from current literature according the criteria as outlined by Neitsch et al. (2002). All data used for pineapple plant growth simulations is summarized in Oestreicher (2008a) and model validation procedures and results are discussed (Oestreicher 2008b).

Model Calibration and Validation After the set-up procedure was completed, the SWAT model was run for a simulation period from January 1, 2004 to December 31, 2006 for the CQ basin. Model calibration and validation are two distinct, but related, procedures that are essential for ensuring and quantifying model accuracy. Calibration is the adjustment of model parameters to maximize the “goodness-of-fit” of model output with an observed dataset, while validation is the comparison of the calibrated model with an independent set of observed data and involves no further parameter adjustments.

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Streamflow and suspended sediment data for 2004 and 2005 from the CQ1 station were used for calibration and data from 2006 was used for validation. All data were adapted from daily streamflow and sediment records provided by the ACP (ACP 2005, 2006, 2007). Although available, data from 2003 was excluded from calibration and validation procedures for two reasons. Firstly, precipitation records from the ZAN station, of closest proximity to CQ1, are incomplete for all of 2003, thus the model may not generate an accurate representation of streamflow at this site. Furthermore, 2003 emerged as an unusual hydrologic year in the Caribbean region due to an El Niño event. This increased seasonal temperatures and prompted a drier-than-average dry season and heavy rains during the wet season (Levinson and Waple 2004). Model calibration using data from years that significantly deviate from the average could result in unsuitable parameter modifications and would, consequently, compromise the model’s ability to accurately simulate processes. 2 The Nash-Sutcliffe (ENS) coefficient of model efficiency and the r-squared (r ) coefficient of determination (Arnold and Fohrer 2005) were both used as indicators of model performance for calibration and validation periods. The r2 coefficient of determination is calculated using the following equation:

   r2     

    ( O O )( P P )  i i  i 1  n n 2 2  (Oi  O)  ( Pi  P)   i 1 i 1 

2

n

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The ENS coefficient of efficiency is calculated using the following equation:

 (P  O )  1  (O  O) i

E NS

2

i

i

2

i

i

Where Pi is the predicted value Oi is the observed value at time i, Ō is the mean observed value, and P is the mean predicted value for the entire time period i. Models with higher ENS and r2 coefficients (ranging between 0 and 1) are presumed to perform better than models with lower coefficients. According to Krause et al. (2005), using ENS and r2 to evaluate hydrological model performance has limitations due to their sensitivity to peak flows. This sensitivity, Krause et al. (2005) points out, is because parameter calculations are based on the square of the difference between the simulated and the observed values; therefore, these parameters are unreliable indicators of model performance for low flows. To account for this sensitivity, Krause et al. (2005) propose variations of ENS and r2

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which are similar or superior indicators of model performance. One of the proposed variants, the relative coefficient Erel, is calculated with the equation (Krause et al. 2005):

  

2

 Oi  O      O  i 1  

2

 Oi  Pi   Oi i 1   1 n

E rel

n

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2

The ENS and r coefficients were chosen for this study as they are recommended for use with SWAT (Neitsch et al. 2002). Using indicators of model performance that are consistent 2 with current literature, such as ENS and r , also facilitates model comparison. The relative Nash-Sutcliffe (Erel) coefficient, a less sensitive coefficient recommended by Krause and colleagues was also calculated to validate the reliability of ENS as a model performance indicator for this study. The calibration procedure was performed in a step-wise fashion; model parameter input values were adjusted (decreased or increased) by a certain incremental value that varied for individual parameters according to their respective input range. The effect of these input 2 alterations on observed streamflow and sediment from CQ1 was evaluated with the ENS and r coefficients. These were then compared with the coefficients derived from model output from 2 the previous incremental change. If the ENS and r coefficients increased, the parameter value would again be altered by the same increment; if the value decreased, the parameter would be altered (decreased or increased) at a smaller incremental change (generally half of the previous increment). If the model efficiency was lower, the previous parameter value would be considered the final value, if not, the parameter would be again adjusted in the same incremental fashion. This step-wise procedure was iterated several times until optimal values 2 were reached for both the ENS and r coefficients. The effects of parameter adjustments on flow were also visually examined by graphically comparing model output with observed data. Model calibration was first performed with streamflow on a monthly and then a weekly time step. Following streamflow calibration, suspended sediment was calibrated and evaluated at a monthly time-step in a similar fashion. This time-step was chosen because sediment model output is sensitive to land management practices, in particular tillage (Neitsch et al. 2002). All model parameters that were modified during the streamflow and sediment calibration procedures are described in detail in Oestreicher (2008a) and their final values are indicated.

Validation Streamflow and suspended sediment observed at CQ1 in 2006 was used for SWAT model validation. Validation procedures were performed independently of the calibration procedure. The model performance during the validation period was evaluated using the ENS 2 and r coefficients.

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Land Cover Change Scenarios Upon completion of model calibration and validation procedures, the effects of landcover change scenarios on simulated sediment and water yields was projected. Two extreme scenarios were examined that could be engendered by watershed management policies or a PES program to explore the usefulness of the model: 1) conversion of all pineapple-cultivated areas to forest cover; 2) conversion of all pineapple cultivated areas to pasture cover. Simulations were undertaken for a fifty-year period (2005 – 2055).

5. RESULTS

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Stream Flow Calibration and Validation The SWAT model was calibrated with data from 2004 and 2005 and validated with data from 2006 for streamflow and transported sediment at the CQ1 gauge. Initial runs of the uncalibrated SWAT model had a tendency to over-predict flow. Groundwater and evapotranspiration parameters were then adjusted, enhancing model performance for streamflow but leaving baseflow predictions with some error (Table 1). The minor disparity of model performance for the validation and calibration periods of both streamflow and baseflow may be in part justified by the coefficients selected for model 2 evaluation (ENS and r ), which are, according to Krause et al. (2005), sensitive to peakflows. The difference between observed and predicted values (factors in the ENS coefficient numerator) is largest in mid-wet season months when precipitation is intense and peakflows are at their height (Figure 2); thus the calibration period, having a larger sample size, will contain more error than the validation period. The difference in model performance for baseflow calibration and validation periods (ENS difference = 0.1) is about five times that for streamflow (ENS difference = 0.02). Overall, the model tends to over-predict peakflows for baseflow more than for streamflow. Based on this evidence, we can postulate that if the coefficient is very sensitive, the validation period may in fact show better performance due to the chosen evaluation coefficients. Table 1. Model performance coefficients used to evaluate streamflow, baseflow and sediment yield predictions for calibration (2004-2005) and validation (2006) periods Element Stream flow Baseflow Sediment yield

Procedure Calibration Validation Calibration Validation Calibration Validation

R2 0.79 0.76 0.78 0.82 0.52 0.83

ENS 0.78 0.77 0.76 0.66 0.48 0.82

Erel 0.72 0.79 0.62 0.70 -

Application of Soil Water Assessment Tool (SWAT) in Watershed Management

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Figure 2. Example of weekly average flow at CQ1 for calibration period, exhibits that the model simulates recharge and baseflow decline well, while peak flow is often over estimated. Precipitation also shows that the model is more responsive to heavy precipitation that the real watershed and appears to produce instantaneous runoff more quickly.

A comparison of the cumulative probability distributions of simulated and estimated weekly water yield (Figure 3) illustrates that the probability of SWAT generating a value for water yield that is statistically different from the observed value is very low. This is similarity reflected in the results of the Kolmogorov-Smirnov (KS) and Mann- Whitney (MW) tests, which confirm that the distributions of the simulated and observed cumulative water yield do not significantly differ (Table 2).

Sediment Calibration and Validation While SWAT provides good flow predictions, the model is a sub-par predictor of monthly sediment yield in the CQ basin. Mirroring streamflow predictions, model performance is poorest during the calibration period yet the calibration-validation coefficient discrepancy is notably larger (Table 1). Table 2. Results of the Kolmogorov-Smirnov (KS) and Mann-Whitney (MW) tests for cumulative water and sediment yields

Z Score (MW) P value (MW) D statistic (KS) P value (KS) *

Significant at a α = 0.05.

Cumulative Water Yield 1.083* 0.079 0.122* 0.032

Cumulative Sediment Yield 0.304* 0.276 0.278* 0.082

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J. S. Oestreicher Excluding the sensitivity of the ENS coefficient, improvement beyond this performance

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level for the calibration period was unattainable because the model consistently oversimulated suspended sediment in the year 2004 and under-simulated in 2005 (Figure 4). Since calibration years were evaluated together, parameter adjustments during calibration procedures would bring about the simultaneous improvement of model performance for one year and the decline in model performance of the alternate year, resulting in no considerable improvement overall. Although the marked land-use transition in the CQ basin during this time was accounted for in model calibration procedures through land-cover change modeling, the diametric difference in prediction patterns is likely influenced by the uncertainty associated with the erosion parameter inputs, as discussed below, and caveats linked to modeling pineapple land cover (Oestreicher 2008a).

Figure 3. Comparison of the cumulative probability density functions of the log-normal distribution for monthly simulated and observed water yield (primary axes) and the total simulated and observed water yield accumulated at CQ1 for the calibration and validation periods (secondary axes).

Because model performance at the monthly time-step is sub-par, model evaluation at the weekly level was ineffectual. More to the point, weekly sediment yields are not of particular importance in the context of the PCW where reservoir sedimentation is the principal concern; therefore, monthly or annual sediment yield simulations should be sufficient for watershed management planning or decision making. The model does appear to be a good predictor of cumulative sediment yield over the three-year observation period (Figure 5, Table 2). The cumulative probability of the simulated and observed monthly sediment yields demonstrates that there is about a 12% probability that the model will produce a prediction significantly different from the observed value at low to mid-range values (Figure 5). As the monthly sediment yield increases, the probability that model predictions will be different from observed values decreases (as the probability density functions converge). This indicates that the overall probability of the model adequately predicting accumulated sediment over the entire year is high. In fact, for sediment yield predictions beyond 1000 Mg/month or more there is a very low probability that the model

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will be a poor predictor; this is similarly reflected in the results of the MW and KS tests (Table 2).

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Figure 4. Monthly observed and simulated sediment yield and flow at CQ1 for calibration and validation periods. The Cook’s Distance analysis, used to explore the inconsistency between simulated sediment in 2004 and 2005, identified sediment yield simulated for the month of October, 2004 as an outlier with heavy influence on the regression model. Given that the calibration period data set is small and that an extreme precipitation event occurred in October of 2004 (Figure 2, week 44) it was decided that this data point should be excluded.

Figure 5. Comparison of the cumulative probability density functions of the log-normal distribution for monthly simulated and observed sediment yield (primary axes) and the total simulated and observed sediment yield accumulated at CQ1 for the calibration and validation periods (secondary axes).

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Land-Use/Land-Cover SWAT simulates sediment loadings from pasture, the principle land-cover in the CQ basin, to be about 5% of total basin loadings. Principally used for livestock grazing, most range lands in the area have unsustainable carrying capacities and are considered to be overgrazed (AED 2004a; Martiz and Vergara 2004). Taking into account that SWAT cannot model the erosive effects of cattle grazing and hoof trampling, pasture may contribute to erosion in the CQ basin more than SWAT simulations indicate. The largest portion of sediment loadings is from pineapple cover (over 70%). Without more quantitative data from the area, assessing the accuracy of simulated sediment loads from different land-covers and land-management practices cannot be assumed. Acquiring such data would allow fine-tuning of the model and as a result improve basin-wide sediment yield simulations.

Scenarios When compared to the business as usual scenario, cumulative sediment yield reductions over a fifty-year simulation period project reductions of 62% for conversion of pineapple cultured lands to forest cover and 58% when pineapple plantations are converted to pasture cover. However, projected water yield changes are less pronounced. Forest cover increases water yield on average 5% annually (over a fifty year simulation period), while conversion to pasture cover increases yield by only 1% from the business as usual scenario.

6. DISCUSSION Copyright © 2012. Nova Science Publishers, Incorporated. All rights reserved.

SWAT and Payment for Ecosystem Services The SWAT model was calibrated for the CQ river basin to assess its ability to contribute to the development of a Payment for Ecosystem Services (PES) and watershed management planning pilot project in the Panama Canal Watershed (PCW). The calibrated model demonstrated good performance for mean weekly streamflow and baseflow simulation, while monthly sediment yield was simulated with sub-par performance. In applying this model to planning in the greater PWC, where cumulative sediment yield would be most important, fine resolution sediment yield data may not be so crucial. Conversely, estimates of actual erosion on pineapple farms, lands used for grazing and in forest fragments, while not currently available, would be particularly central to using SWAT for the development of a PES project in the basin. In the context of PES, farmers will potentially be earning money for implementing soil conservation techniques and their payments will likely be contingent on successful sediment yield reductions (e.g. the expected reduction within a given range would be determined by the model). Yet, if the model provides only ball-park estimates of the expected sediment yield reductions for a given conservation technique, monitoring mechanisms implemented by the PES program could find that specified reductions are not being met. This would be especially true in the likely case of limited financial resources that would rely on coarse monitoring techniques. It may be assumed, then, that farmers are not adhering to their side of the bargain (soil-conservation)

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even if they indeed were. Given that a PES program could directly alter peoples’ livelihoods in the basin, it seems particularly pertinent to understand the true nature of different erosionprevention mechanisms in situ and calibrate the model accordingly. Effective and efficient use of the SWAT model to develop and implement conservation plans, such as PES, risk analysis, or best management practice recommendations are hindered by issues of data scarcity. This is an important barrier for the PCW, as little data is available and it does not cover a large geographical area. To confidently judge the performance of the model, longer temporal datasets would be required. With only three years of data available, affirming the accuracy and usability of the SWAT model is difficult in terms of planning and policy making. As more data becomes available, the model should continue to be adjusted and validated to further affirm its ability to predict accurately. Despite this limitation, the model results are promising and indicate that future efforts will be a good investment. Information shortages in Panama pertain not only to the GIS data and sediment yield and streamflow data necessary to calibrate a distributed model such as SWAT, but also complementary datasets, socio-economic information for example. This knowledge has been characterized as important for sustainable planning of any watershed or conservation activities, especially PES (Wunder 2005).

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SWAT and Land Cover Change Scenarios The land-cover scenario results project major shifts in sediment yields upon conversion of pineapple plantations to either forest or pasture cover, while projected water yields remain stable. The model thus indicates that either land-cover would produce similar results, yet several in situ studies in the tropics demonstrate that pasture and forest cover do not have the same ecological functions or land management implications and would not yield similar effects on water and sediment yields. Poorly managed pastures with high cattle densities can result in erosion comparable to agriculture, while pastureland that is well managed may result in minimal erosion similar to that of forests, as SWAT seems to indicate (Mwendera and Saleem 1997). SWAT currently has no component for modeling livestock management practices (cattle densities or grazing rotations), thus the effects of trampling or overgrazing on vegetation and erosion cannot be directly integrated. However, a targeted classification of vegetative cover using remote sensing technology and ground-truth data on cattle densities could provide modelers with a means for categorizing pasturelands according to their erosion potential. Modelers can then fine-tune SWAT parameters for each category to make pastures with little to no vegetation and higher cattle densities produce more erosion than areas with more vegetative cover and lower grazing densities. Doing so could improve model accuracy for monthly sediment yields and therefore improve the overall reliability of the model for scenario building and planning. Lack of such data made it difficult to perform such a fine-tuned operation. SWAT also has limitations in modeling forest cover transitions. Currently, vegetation modeled by SWAT is limited to species common to Europe and North America (trees, crops, plants, etc.), which could integrate an unknown level of uncertainty into the model when used in the tropics where plants are different from that of temperate zones (roots depth, water uptake, etc.). Modify the model to simulate other types of vegetation, such as tropical forests, is data intensive (Oestreicher 2008a). Other models could alternatively be combined as a

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J. S. Oestreicher

complement to the SWAT model, such as TOPMODEL, which has been successfully adapted to model water yields in the forested regions of Panama (Kinner and Stallard 2004).

CONCLUSION SWAT is a good tool to complement watershed management planning and conservation decision making through land-cover change and land management scenarios. However, there are several improvements to the model that will need to be addressed before its application can be reliably used. Applying the model to predict more detailed processes, such as the effects of tillage or cropping patters on sediment yield (as required for PES program planning) or land-use change scenarios (required for best management practice recommendations) would necessitate: a) thorough estimates of current erosion in the basin for pineapple crops and under different land management scenarios; b) consideration of the effects direct (grazing) and secondary (trampling) effects of cattle on sediment generation; and c) improved parameter estimates to reduce model uncertainty and longer temporal datasets for calibration and validation.

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ACKNOWLEDGMENTS This research could not have been completed without the academic, financial and logistical support from Dr. Robert Bonnell, Catherine Potvin, the Neotropical Environmental (NEO) program at McGill, the Levinson family, the Smithsonian Tropical Research Institute, the Instituto de Investigaciones Agropecuarias de Panama including Rubiela Garcia, Ruth del Sid, Manuel de Gracia and Miguel Saramiento, the Centro International de la Papa especially Dr. Robert Quiroz, Percy and Heline, Dr. Duane Bartholemew.

REFERENCES ACP. (2005) Anuario hidrologico 2004, ACP, Panama City. ACP. (2006) Anuario hidrologico 2005, ACP, Panama City. ACP. (2007) Anuario hidrologico 2006, ACP, Panama City. AED. (2004a) Estudio Hidrogeologico en las subcuencas de los Hules, Tinajones y Caño Quebrado, Academy for Educational Development and USAID, Panama. AED. (2004b) Proyecto silvopastoril y manejo ambiental de la ganadería en las subcuencas de Los Hules, Tinajones y Caño Quebrado, Academy for Educational Development, CICH, and USAID, Panama. ANAM, ITTO. (2003) Informe Final de Resultados de la Cobertura Boscosa y Uso del Suelo de la Republica de Panama: 1992 - 2000, Panamá. Anderson K. (2007) Existing Supply of Watershed Services in the Panama Canal Watershed, in: B. Gentry, et al. (Eds.), Emerging Markets for Ecosystem Services: A case of the Panama Canal Watershed, Haworth Press.

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Application of Soil Water Assessment Tool (SWAT) in Watershed Management

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Arnold J.G., Fohrer N. (2005) SWAT2000: current capabilities and research opportunities. Hydrological Processes 19:563 - 572. Arnold J.G., Srinivasan R., Mittiah R.S., Williams J.R. (1998) Large Hydrologica Modeling and Assessment Part I: Model Development. Journal of the American Water Resources Association 34:73 - 89. Barsanti P., Disperati L., Marri P., Mione A. (2003) Soil erosion evaluation and multitemporal analysis in two Brazilian basins, 2nd International SWAT Conference, ASAB, Bari, Italy. Benavides F., Veenstra J.N. (2005) The Impact of Tropical Deforestation on River Chemical Pollution. Global NEST Journal 7:180 - 187. Bruijnzeel L.A. (2004) hydrological functions of tropical forests: not seeing the soil for the trees? Agriculture, Ecosystems and Environment 104:185 - 228. FAO, UNESCO. (2003) Map of World Soil Resources, Rome, Italy. Fotos M., Chou F., Newcomer Q. (2007) Assessment of Existing Demand for Watershed Services in the Panama Canal Watershed, in: B. Gentry, et al. (Eds.), Emerging Markets for Ecosystem Services: A case of the Panama Canal Watershed, Haworth Press. IDIAP. (1996) Proyecto de Muesto de Suelos. IDIAP. (2007) Resultados de las entrevistas del los pineros, IDIAP, Panama. Jacobs J., Angerer J., Vitale J., Srinivasen R., Kaitho R., Stuth J., Clarke N. (2003a) Exploring the Potential Impact of Reforestation on the Hydrology of the Upper Tana River Catchment and the Masinga Dam, Kenya, Center for Natural Resource Information Technology. Jacobs J., Angerer J., Srinivasan R., Kaitho R., Stuth J., Vitale J., Clarke N. (2003b) Integrating ground and charm weather data with the SWAT hydrological model to assess reforestation impacts in the Upper Tana River Basin of Kenya, Center for Natural Resource Information Technology. Kinner D.A., Stallard R.F. (2004) Identifying Storm Flow Pathways In A Rainforest Catchment Using Hydrological and Geochemical Modelling. Hydrological Processes 18:2851 - 2875. Krause P., Boyle D.P., Base F. (2005) Comparison of the different efficiency criteria for hydrological model assessment. Advances in Geosciences 5:89 - 97. Lal R. (1990) Soil Erosion in the Tropics: principles and management McGraw-Hill, USA. Levinson D.H., Waple A.M. (2004) State of the Climate in 2003, American Meteorlogical Society. Marín M.D., Yee C. (2004) Diagnóstico de las condiciones de saneamiento básico en las subcuenceas Los Hules, Tinajones y Caño Quebrado, Academy for Educational Development, Comisión Interinstitucional de la Cuenca Hidrográfica del Canal, Panama. Martez J.A.L., Vergara L.K. (2004) Caracterización de la actividad piñera de las subcuencas Los Hules, Tinajones y Caño Quebrado, Academy for Educational Development, Commisión interinstitutional de la cuenca hídrografíca del Canal de Panamá, Panama. Martez J.A.L., Vergara L.K. (April 2004) Caracterización de la actividad piñera de las subcuencas Los Hules, Tinajones y Caño Quebrado, Academy for Educational Development, Commisión interinstitutional de la cuenca hídrografíca del Canal de Panamá, Panama. Martiz G., Vergara L.K. (2004) Caracterización de la Actividad Ganadera en las Subcuencas de Los Hules-Tinajones y Caño Quebrado, AED, CICH, and USAID, Panama.

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MEA. (2005) Ecosystems and Human well-being Island Press. Mwendera E.J., Saleem M.A.M. (1997) Infiltration rates, surface runoff, and soil loss as influenced by grazing pressure in the Ethiopian highlands. Soil use and Management 13. Neitsch S.L., Arnold J.G., Kiniry J.R., Srivivasan R., Williams J.R. (2002) Soil and Water Assessment Tool Users Manual - Version 2000. Oestreicher J.S. (2008a) Using computer models to support soil conservation and erosion evasion initiatives for pineapple crops in the Panama Canal Watershed. Pineapple News of the International Society for Horticulture Science 15. Oestreicher J.S. (2008b) Application of the Soil Water Assessment Tool in a Tropical Agricultural Watershed: Implications for payment for ecosystem services program and watershed management planning in the Panama Canal Watershed., Bioresource Engineering, McGill University, Montreal. pp. 145. OIRSA. (1999) Manual Técnico: Buenas Practicas de Cultivo en Pina, El Organismo Internacional Regional de Sanidad Agropecuaria, Panama. Ouyand W., Hao F., H.G.Cheng, Wang X.L. (2007) Non-point source pollution responses simulation for conversion of cropland to forest in mountains by SWAT in China, 4th International SWAT Conference, UNESCO-IHE, Delft, The Netherlands. PMCC. (1999) Panama Canal Watershed Monitoring Project, USAID, STRI, ANAM, Panama. Rivera S., Martinez W.N. (2003) The Effect of land use dynamics on stream flow fluctuations: A SWAT simulation conducted in a third-order watershed of central Honduras, in: A. Saleh (Ed.), TMDL Environmental Regulations - II, ASAE, Albuquerque, New Mexico. pp. 154 - 160. Saxton K.E., Rawls W. (2005) Soil Water Characteristics by Texture and Organic Matter for Hydrologic Solutions, Soil Science Society of America, Annual Conference, Seattle, WA, USA. Saxton K.E., Rawls W. (2006) Soil Water Characteristics by Texture and Organic Matter for Hydrologic Solutions. Soil Science Society of America Journal 79:1569 - 1578. Sharpley A.N., Williams J.R. (1990) EPIC-Erosion Productivity Impact Calculator model documentation, U.S. Department of Agriculture, Agricultural Research Service. Singh A., Gosain A.K. (2007) Water Allocations using GIS based Hydrolgical Modelling, 4th International SWAT Conference, UNESCO-IHE, Delft, The Netherlands. USDA, NSCR. (2005) Global Soil Regions Map, Washington, D.C. Wischmeier W.H., Johnson C.B., Cross B.V. (1971) A soil erodibility nomograph for farmland and construction sites. Journal of Soil and Water Conservation J26:189 - 193. Wunder S. (2005) Payments for environmental services: Some nuts and bolts, CIFOR Occacional Paper No. 42, Jakarta, Indonesia.

In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 3

ORGANIC AMENDMENTS FOR AGRICULTURE LAND RESTORATION PRACTICES Surendra Suthar1,, Sushma Singh2 and Pravin Mutiyar3 1

School of Environment & Natural Resources, Doon University, Dehradun, India 2 Department of Chemistry, Nehru Memorial PG College, Hanumangarh Town, India 3 Indian Institute of Technology, Hauz Khas, New Delhi, India

ABSTRACT Copyright © 2012. Nova Science Publishers, Incorporated. All rights reserved.

The continuous application of synthetic fertilizers has raised several issues like soil biodiversity depletion, loss of natural detoxification capability of soils, soil acidification, low soil organic matter, and low soil fertility. The low soil productivity and a hike in price of fossil fuels have raised the question of sustainability of modern farming system. The issues of agriculture sustainability need to be addressed effectively in order to meet the challenges of ever-growing human populations and future food security. It is clear that apart from chemical inputs though synthetic fertilizers another sources of nutrient supply in cropping system need to be explored. Livestock excreta, crop residues, human excreta etc. are some potential sources of nutrient for crop production. It is interesting that each year, human, livestock and crops produce approximately 38 billion metric tons of organic waste worldwide, which may be an efficient source of organic matter supply in soils. On the other hand soil organic matter (SOM) which plays a fundamental role in the maintenance of the main soil properties and regimes related not just to the soil fertility has been depleted in modern agro-ecosystems with synthetic-chemical inputs. The decline in soil fertility and productivity due to excessive soil erosion, nutrient run-off, and loss of SOM has stimulated interest in improving overall soil quality by the addition of organic matter. Organic farming systems which involve the use of catch crops, the recycling of crop residues, the use of organic rather than artificial fertilizers, and the use of perennial crops are assumed to promote higher levels of organic matter in the soil. Organic manure (compost and vermicompost, farmyard manure etc.) has number of apparent agronomic and environmental advantages. The recycling of organic wastes 

Tel. (91) 135 2255103, E-mail: [email protected].

40

Surendra Suthar, Sushma Singh and Pravin Mutiyar (crop residues, livestock excreta, source-segregated municipal solid wastes, agroindustrial wastes etc.) through composting/vermicomposting methods is the key technology for disposal of organic manures. Results of recent case studies clearly suggested that in containerized production systems, vermicompost used as an alternative soil amendment could help reduce several problems associated with the use of conventional synthetic fertilizer such as excessive leaching loss of nutrients and salinityinduced plant stress. In addition compost/vermicompost can improve soil porosity, and thus provide a better root growth medium.

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1. INTRODUCTION The modern technology and chemicals considerably raised outputs and enabled new cultivation even in less than fifty years of modern farming; it has started showing many negative effects such as land degradation, increasing per capita production cost, pesticide contamination in biological resources, environmental deteriorations, soil fertility degradations etc. In synthetic chemical-based farming system the nutrients are supplies in ready forms of NPK for plants. However, the continuous applications of synthetic nutrients in soils have been deteriorating the soil health and soil biological fertility. Soil fertility holds the key to soil quality which has aptly been defined as the quality of a soil to produce safe and nutritious crops in a sustained manner over a long-term and to enhance human and animal health without impairing the natural base or harming the environment (Chonkar and Rattan, 2000). The continuous application of nitrogen-based fertilizers alone causes sharp reduction in soil organic matter levels, a key indicator of soil quality, irrespective of the cropping systems and soil types. Deficiencies of nutrients other than NPK have appeared in soils continuously supplied with NPK. In addition to the primary nutrients (NPK), less intensively used secondary nutrients (sulfur, calcium, and magnesium) are necessary as well. A number of micronutrients such as chlorine, iron, manganese, zinc, copper, boron, and molybdenum also influence plant growth. These micronutrients are required in small amounts (ranging from a few grams to a few hundred grams per hectare) for the proper functioning of plant metabolism. Soil acidification and enhanced level of some metal toxicants in soils with continuous supply of ammonium sulphate and urea is also reported in some Indian soils (Chhonkar and Rattan, 2000).

2. CHEMICAL FERTILIZER: DEMAND, SUPPLY AND SUSTAINABLE SOLUTION? The world fertilizer consumption is to grow annually at about 1.7 % from 2007/2008 to 2011/2012, equivalent to an increment of about 15 million tons. About 69% of this growth will take place in Asia and 19% in America. The overall scenario of demand and supply of NPK fertilizer in Asia is described in Table 1. It is clear that chemical based-farming system needs more resources for sustainable crop productivity. The hike in oil prices led to increase in production and supply cost of fertilizers which resulted in economical burdens to smallscale farmers which cannot affords such expensive chemical based farming practices.

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Organic Amendments for Agriculture Land Restoration Practices

41

In India about 7.54 % increment in total fertilizer (NPK) demand has been recorded during the last decade (Figure. 1). However, current production capability in country did not fulfill the demand therefore majority of K fertilizer is imported from other countries. It is clear that apart from chemical inputs though synthetic fertilizers another sources of nutrient supply in cropping system need to be explored. Livestock excreta, crop residues, human excreta etc. are some potential sources of nutrient for crop production. It is interesting that each year, human, livestock and crops produce approximately 38 billion metric tons of organic waste worldwide, which may be an efficient source of organic matter supply in soils. According to Lal (2005) the annual crop residue production in the world is estimated at 2.8 billion Mg of cereals, 305 million Mg of legumes, 108 million of oil crops, 373 million Mg of sugar crops and 170 million Mg of tubers (Table 2). Although, crop residue biomass may be used as fodder, fibers, industrial raw material or a soil amendment (Lal, 2005) and may have multi-facet uses, but integrated approaches to utilize the crop residues for industrial, animal husbandry, crop production, bioenergy production, industrial development, and soil amendment technology may be a key component of sustainable environmental development. In India, around 600 to 700 million MT of agricultural waste (including 272 MT of crop residues) are available every year, but most of it remains unutilized. The crop residue contains a high range of NPK and that can be converted into products for supply of nutrients to plants. Nevertheless, a great proportion of the crop nutrient input during cultivation returned in the form of the plant residues. Estimation showed that 30-35 % of applied N and P and 70-80 % for K remained in the crop residues of food crops (Suthar, 2007). The livestock excreta have also been used traditionally as fertilizers in many part of the world. However, small or marginal farmers especially in India use cattle manure along with recommended NPK for cereals and fodder crops in order to minimize the production costs. Livestock excreta and other community wastes have great potential in order to meet the current nutrient demand in the country. According to the estimation of National Academy of Agricultural Sciences, to meet the 25 % nutrient demand of Indian soils in 2000 AD, about 200 million tons farmyard manure, 30 million tons crop residues and 10 million tons urban waste/rural waste will be required. Against these requirements, theoretical and tappable availability of human excreta, livestock dung and crop residues during this period will be 16.5 and 13,375 and 113, and 300 and 99 million tons (Figure. 2) respectively (Tandon et al., 1997). Such nutrient rich organic wastes must be processed biologically before they are used as a fertilizer and composting or vermicomposting seem to be appropriate candidates for this process. Composting or vermicomposting may be an appropriate technology to recover these nutrients from wastes and convert into organic fertilizers. Livestock waste solids may be utilized effectively as resource for energy and nutrient supply in rural India. Livestock excreta which are a major byproduct of agriculture based industry have made an important contribution to soil nutrient inputs, since ancient time; although their relative importance has decreased in modern crop production practices due to heavy use of mineral fertilizers. In India, millions of tons of livestock excreta are produced annually. Disposal of manure from intensive livestock has raised a problem all over the world. The best solution is to recycle the manure as an organic fertilizer.

42

Surendra Suthar, Sushma Singh and Pravin Mutiyar Table 1. Asia fertilizer production and consumption

N

P

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K

Demand Supply Surplus (deficit) Demand Supply Surplus (deficit) Demand Supply Surplus (deficit)

2007 - 08 75255 72123 (2132)

2008 - 09 76111 76317 206

2009 - 10 77961 79933 1972

2010 - 11 80431 85491 5078

2011 - 12 82476 89850 7374

19209 13882 (5327)

19890 14744 (5146)

20560 15484 (5076)

21168 16185 (4983)

21784 17964 (3820)

14485 5428 (9057)

15138 5524 (9614)

15794 6226 (9568)

16464 6450 (10014)

17073 6530 (10543)

Figure. 1. Trends in fertilizer consumption in India (Source: Fertilizer Associate of India, 2010) [4].

India is known as a country with the largest number of cows and buffaloes in the world. The total number of all kinds of cattle and buffaloes well exceed 400 million. In other words, one sixth of the world's cows and one half of the world's buffaloes live in India. India possesses one of the largest livestock populations in the world. In 1992 the country had 205 million cattle, 84 million buffalo, 115 million goats, 51 million sheep, 13 million pigs, 1 million horses and 307 million poultry. Currently the fertilizer values of animal dung are not being fully utilized resulting in loss of potential nutrients returning to agricultural systems. Table 3 describes the cattle population and total dung production in the country during 2003. Traditionally, compost prepared from cattle waste solids is considered as one of the potential sources for soil nutrients for commercial cropping systems in rural India. Livestock excreta are rich in soil nutrients (Table 4) and microbial population which can be utilized effectively to restore land biological as well as chemical structure. Animal manure increases

Organic Amendments for Agriculture Land Restoration Practices

43

soil OM content, soil aggregate stability, water-holding capacity, water infiltration and hydraulic conductivity and decreased bulk density and evaporation rate (Eck and Stewart, 1995). The composted animal manure is always better than raw materials for soil applications. Studies have supported the fact that the composted material is always better than raw materials for land applications. For example, Bernal et al. (1998) found that the degradation of raw animal manure in the soil led to a higher CO2 production than that of composted animal manure, which could cause anaerobic and reducing conditions in the soil, due to the decreased O2 level. Composting may be a sound tool to enhance the quality of cattle dung prior to land application.

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Table 2. Production and chemical characteristics of major crop residues Crop

Residue production in (106 Mg) (FAO, 2001)

Rice straw Wheat straw Sorghum Millet Corn Total pulses Pigeon peas Chickpea Sugarcane Oilseeds Cotton

152 214 43 379 138 66 6.65 5.05 19 70 16

Nutrient contents % (oven dry basis) N 0.58 0.49 0.40 0.65 0.59 1.60 1.10 1.19 0.35 -

P 2O 5 0.23 0.25 0.23 0.75 0.31 0.15 0.58 0.04 -

K 2O 1.66 1.28 2.17 2.50 1.31 2.00 1.28 1.25 0.50 -

Figure. 2. Some projection on the availability of organic resources for agriculture in India during 2000 – 2025 (Source: Tandon, 1997). Tappable – 30 % of dung, 80 % excreta, 33 % of crop residues.

44

Surendra Suthar, Sushma Singh and Pravin Mutiyar Table 3. Cattle population and dung production in India during 2003 Livestock Bovines

Population (million) 285.1

Dung production (million kg/day) 1273.95 a

Annual dung production (million tons) 468.28

Sheep

61.5

24.6 a

8.98

Goat

124.4

Pig

13.5

Poultry a

49.8

489.0

a

18.18

36.45

b

13.3

19.56

b

7.14

Dun yield data used in the estimation of dung production: 4.5 kg/bovine/day and 0.4 kg/day/sheep or goat; b American standards.

3. SOIL ORGANIC MATTER (SOM) UNDER CHEMICAL FARMING SYSTEMS: AN ISSUE OF CONCERN According to Smith et al. (1999) soil organic matter (SOM) plays a fundamental role in the maintenance of the main soil properties and regimes related not just to the soil fertility. The whole functioning of soils is profoundly influenced by SOM, its ability to provide conditions for plant growth, soil biota functioning, reduction of greenhouse gases, modification of pollutants and maintenance of soil physical condition.

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Table 4. The chemical characteristics of animal manure (Moral et al., 2005). All values in per cent except C/N and NH4+-N/NO3--N ratio

*

Manure

OM

Total C

Organic N

C/N ratio

HI*

Horse Cow Pig Sheep Goat Rabbit Chicken

69.7 39.6 67.7 51.3 54.6 65.0 45.6

41.5 22.5 40.7 31.4 29.5 36.5 32.6

1.9 1.5 2.1 1.8 1.9 1.7 2.9

20.8 14.2 19.1 17.7 13.2 20.4 11.1

3.38 2.85 1.86 3.80 3.56 1.15 3.62

NH4+N/NO3--N 0.82 0.32 0.89 0.48 0.15 1.20 1.01

Humification index.

The great importance of detailed estimates of C stocks emphasizes the need to understand the role of SOM dynamics and quantitative changes as affected by natural conditions and sitespecific management (Swift, 2001). The depletion of SOM from conventional farming system not only affects the soil physical structure but at the same time also influences the natural soil detoxification efficiency. Many common agricultural practices, especially ploughing, disctillage and vegetation burning, accelerate the decomposition of soil organic matter and leave the soil susceptible to wind and water erosion. On the other hand, the conservation agriculture encompasses a range of such good practices through combining no tillage or minimum tillage

Organic Amendments for Agriculture Land Restoration Practices

45

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with a protective crop cover and crop rotations. It maintains surface residues, roots and soil organic matter, helps control weeds, and enhances soil aggregation and intact large pores, in turn allowing water infiltration and reducing runoff and erosion. In addition to making plant nutrients available, the diverse soil organisms that thrive in such conditions contribute to pest control and other vital ecological processes. The decline in soil fertility and productivity due to excessive soil erosion, nutrient run-off, and loss of SOM has stimulated interest in improving overall soil quality by the addition of organic matter (Bastian and Ryan, 1986). The supply of organic matter plays a central role in the maintenance of soil fertility. Changes in SOM caused by new farming practices may manifest themselves for the first time many years later (>100 years). In the longer term, use of the same agricultural practice will produce a balance between decomposition and accumulation processes with the pool of organic matter remaining constant (Hansen et al. 2001). The organic matter accumulation in soils can be enhanced by such farming techniques including zero tillage, organic farming, maintenance of permanent grassland and cover crops, mulching, manuring with green legumes, application of farmyard manure, compost, vermicompost, strip cropping and contour farming (Roldan et al., 2005). According to Lal (1991) it may be possible to build up organic matter levels in agricultural soils by cropping with perennial grass, or by applying large amounts of organic matter in the form of crop residues or animal manure. Organic farming systems which involve the use of catch crops, the recycling of crop residues, the use of organic rather than artificial fertilizers, and the use of perennial crops are assumed to promote higher levels of organic matter in the soil. In recent years increasing fertilizer inputs cost, soil health, sustainability and pollution consideration have led to renewed interest in use of organic manure.

4. ORGANIC FARMING: A SOLUTION FOR MANIFOLD PROBLEMS OF MODERN CHEMICAL FARMING SYSTEM Organic agriculture is a holistic approach based upon a set of processes that leads to sustainable ecosystem, safe and nutritive food, animal welfare and social justice. The organic farming is define in various ways, but the definition as described by Lampin (1990) appears to be the most comprehensive one covering all essential components and principles. As per this description” organic farming is a production system which avoids or largely excludes the use of synthetic compounds like fertilizers, pesticides, growth regulators and livestock feed additives. To the maximum extent feasible, organic farming system relies on crop rotations, crop residues, animal manures, legumes, green manures, off-farming organic wastes and aspects of biological pest control to maintain soil productivity, to supply plant nutrients and to control insects, weeds and other pests”. Moreover, organic agriculture is based on three strongly interrelated principles under autonomous ecosystem management, mixed farming, crop rotation and organic cycle optimization. In organic agriculture system the soil fertility is maintained and enhanced in a sustainable manner by a system, which optimize soil biological activity and physical and mineral nature of soil as the means to provide a balanced nutrient supply for plant and animal life as well as to conserve soil resources with the recycling of plant nutrients part of the fertilizing strategy. Organic manure derived from community wastes may be a good option for supplying SOM and other essential soil nutrients in cropping

46

Surendra Suthar, Sushma Singh and Pravin Mutiyar

lands. Organic manure (compost and vermicompost, farmyard manure etc.) has number of apparent agronomic and environmental advantages. The recycling of organic wastes (crop residues, livestock excreta, source-segregated municipal solid wastes, agro-industrial wastes etc.) through composting/vermicomposting methods is the key technology for disposal of organic manures. Composting is a biochemical process in which diverse and mixed groups of micro-organisms (bacteria, fungi, actinomycetes and protozoa) break down organic materials into humus-like substances. The resulting product has a lower bulk volume than the original materials and also high range of essential plant nutrients. The vermicomposting is stabilization of organic material through the joint action of earthworms and microorganisms. While, microbes are responsible for biochemical degradation of organic matter, earthworms are the important drivers of the process, conditioning the substrate and altering the biological activity. Earthworm’s foregut acts as mechanical blenders and modifies the physical status of ingested organic wastes and consequently increases the surface area for digestive enzyme actions. In earthworm, the gut-associated-microbes provide several essential enzymes (exogenous) required for rapid digestions of ingested organic fractions (Suthar, 2010). Vermicomposting procures a better quality product than traditional composting system in terms of nutrient availability. Compared to conventional composting systems the vermicomposting often results in mass reduction, shorter time for processing and high levels of humus with reduced phytotoxicity in ready material (vermicompost). The major characteristics of vermicompost and compost are described in Table 5. Table 5. Chemical characteristics of vermicompost and FYM

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Parameters pH -1 orgC (g kg ) -1 totN (g kg ) -1 avaiP (g kg ) Organic matter (g kg-1) C/N ratio -1 exchK (g kg ) -1 exchCa (g kg ) -1 exchMg (g kg ) -1 exchNa (g kg ) -1 extCu (mg kg ) -1 extFe (mg kg ) -1 extMn (mg kg ) -1 extZn (g kg )

Vermicompost Suthar (2009 f) 7.82  0.04 286.5  1.67 23.1  1.0 9.85  0.10 495.5  2.7 12.3  0.13 15.2  0.19 23.8  2.91 6.74  0.10 6.03  0.06 0.97  0.04 8.68  0.14 13.6  0.18 16.9  0.17

Farmyard manure Suthar (2009 f) 7.81  0.01 266.3  0.51 14.4  0.31 6.59  0.03 461.2  1.31 18.5  0.13 8.87  0.05 15.7  1.31 2.59  0.06 5.70  0.01 0.77  0.01 5.59  0.121 7.72  0.12 8.31  0.10

Organic Amendments for Agriculture Land Restoration Practices

47

5. IMPACT OF ORGANIC AMENDMENTS ON SOILS QUALITY: A CASE STUDY 5.1. Background The use of manures from animal excreta as organic fertilizer can benefit agriculture and can be potentially, an inexpensive way for society to protect the environment and to conserve natural resources (Moral et al., 2005). A study of changes in soil characteristics was conducted in a agriculture filed which is under organic farming operation since last 6 years. The major organic nutrient inputs includes: compost, vermicompost, vermin-wash, crop residues and livestock excreta. Apart to that other inputs in terms of pest management were also of organically derived. The study area is located at Chamanpura village of Saharanpur district of Uttar Pradesh. In this region few farmer communities warmly adopting organic farming practiced as a result of encouragement of local government and social awareness. Wheat, vegetables, fodder are the main crops grown in this agriculture plots using organic amendments. The study of chemical characteristic of soils in wheat cropping system was conducted during 2010. To compare the results of introduction of organic farming practices on soil quality a separate study on soil characteristics of conventional (chemical-based) farming system was also conducted in the same village. In conventional farming system the nutrient inputs is mainly of synthetic chemicals (ammonium based fertilizers) and for pest management is also through chemical pesticides. The detail of cropping history, chemical and other inputs in each study plot is described in Table 6.

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Table 6. Inputs in both conventional and organic crop of wheat in experimental field Inputs

quantity

Application frequency

Application time

Organic farm Compost Vermicompost

1000 kg/ac 500 kg/ac

1 2

5 litre/ac 200 kg/ac 5 litre/ac 5 kg/ac

2 1 2 1

after three month sowing time and after three month sowing time & flowering time At the time of sowing

50kg/ac 50 kg/ac 1 litre/ac 300 kg/ac Weedicides 5 kg/ac 1000 kg/ha

3 1 2 1 1 1 1

Vermi-wash Agriculture waste Organic pesticide Weed management Soil supplement Chemical-based farm Urea DAP Pesticide Agriculture west Weed management Soil supplement FYM

sowing time & flowering time after two month At the time of sowing During pest attack At the time of sowing At the time of sowing At the time of sowing

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Surendra Suthar, Sushma Singh and Pravin Mutiyar

5.2. Results and Discussion The results of soil analysis for both farming system is described in Table 7. pH of soils in the ranges of 7.4 – 7.5 in organic field and 7.1 – 7.2 in conventional filed. pH of soil indicates overall chemical health of the cultivating soils and in this study the low pH in conventional farm than organic system could be due to type of chemical inputs in the field. The use of ready N-fertilizer in the form of urea and ammonium phosphate probably causes slight acidic impact in soils. EC indicates the level of cations in soils and in this experiment EC was comparatively higher in conventional farms than organic filed. It was mainly due to the supply of inorganic fertilizers and more availability of dissolved forms of some key nutrients like nitrate, sulphate and phosphate. In organic supplements such nutrient release gradually and hence increases the rate of plant uptakes. Acidity is an important feature of soil health and it directly indicates the adverse impacts of chemical fertilizers in the soils. In conventional farming systems which receive heavy dose of N-fertilizer and other inorganic nutrient supplements showed slightly more soil acidity value than organic farm. Several other workers also have reported the problem of soil acidity in chemical-based farming systems (Bouman et al., 1995; Barak et al., 1997) [20]. Table 7. Chemical characteristics of soils under different farming systems

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Parameters

pH EC m Acidity (ml/L) TOC (%) TP (mg/kg) PO43-(mg/kg) SO42- (mg/kg) N-NO3- (mg/kg) Ca 2+ (mg/kg) Mg2+ (mg/kg) Total Na (mg/kg) Total K (mg/kg)

Faming system Organic farm Conventional farm Depth Depth 10cm 25cm 10cm 25m 7.5 7.4 7.2 7.1 647 635 700 709 63 61 66 63 23 21 18 16 908 900 788 787 59.7 59.1 48.7 48.1 50.7 49.7 53.1 51.9 18.2 17.8 17.5 17.0 792 781 751 450 159 152 155 154 113 111 110 109 108 106 107 105

Total organic carbon (TOC) is an important component of soil ecosystem and it reflects the overall quality of the soil and productivity of agroecosystems. In this study the organic carbon varied among different sampling stations. In this study TOC was higher in sampling plots which received organic amendments. The TOC ranged 21 (10 – 25 cm depth) – 23 (0 – 10 cm depth) % in organic plot and 16 (10 – 25 cm depth) – 18 (0 – 10 cm depth) % in conventional farming system. Data suggests the significant impact of organic amendments on carbon budget of the soils. Soil carbon dynamics play a crucial role in sustaining soil quality, promoting crop production and protecting the environment (Doran and Parkin, 1994; Robinson et al., 1996). The soil organic

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Organic Amendments for Agriculture Land Restoration Practices

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carbon (SOC) pool, a significant indicator of soil quality, has many direct and indirect effects on such quality. Increases in the SOC pool improve soil structure and tilth, counter soil erosion, raise water capacity and plant nutrient stores, provide energy for soil fauna, purify water, denature pollutants, enhance soil biodiversity, improve the crop/crop residue ratio and mitigate the effects of climate (Lal, 2007). Sombrero and de Benito (2010) reported a high TOC pool in soils of agriculture plot receiving conservative farming inputs. They attributed the high TOC pool in soils to addition of organic residues to soils. Nitrate is an essential component required for plant growth and development. Application of inorganic N may influence soil structural properties through changes in root development, microbial community composition and activity, SOC concentration, and soil chemical properties (e.g., flocculation, zeta potential) (Haynes and Naidu, 1998). The nitrate was relatively higher in organically managed agroecosystems than the conventional farm. The ranges of nitrate in soils of organic farming system was 17.8 (subsoil: 10- 25 cm depth) – 18.2 (topsoil: 0 – 10 cm depth) mg kg-1 while in conventional farm N-NO3- ranged between 17.0 (subsoil: 10- 25 cm depth) – 17.5 (topsoil: 0 – 10 cm depth) mg kg-1. The high nitrate in organic farming system could be due to slow release of N-NO3- from organic pools through natural mineralization processes. This process conserve N pools in soils while in chemical based farming system readily available N sources either absorbed by plant systems or some fraction is lost through surface runoff or deep soil leaching. The slow mineralization of nitrate in compost material is of prime importance because it conserves the N-pool in the soils. The high nitrate some time leach down to deep soil layers and consequently causes pollution to groundwater. Phosphate is important plant nutrient and essentially required for several plant functions and soil microbial richness. The soil phosphate content did not varied drastically between the conventional and organically managed agriculture plots, but in some areas the phosphate was relatively high in organic farm soils. The phosphate in organically managed soils was 59.1 (subsoil: 10 – 25 cm depth) – 59.7 (topsoil: 0 – 10 cm depth) mg kg-1. In conventional farm the phosphate ranged: 48.1 (subsoil: 10 – 25 cm depth) – 48.7 (topsoil: 0 – 10 cm depth) mg kg-1 mg/kg. The chemical input of phosphate is the main source of phosphate in conventional farming systems, while in organically managed agroecosystems compost as well as vermicompost was applied at appropriate rate in order to meet the necessities of essential plant nutrients in soils. Vermicompost contains a high range of plant available form of phosphorous and hence acts as potential source of phosphate in soils (Suthar, 2009, 2010). Plant-derived wastes (farmyard manure, composted crop residues etc.) and animal excreta is important source of phosphate in soils and majority of organic manures were prepared from either animal excreta or crop residues spiked with cattle dung. Sulphate is very essential nutrient for microbial growth and plant metabolism. The overall range of sulphate was relatively high in soils of conventional farming systems than organically managed farm. In organic farming plot the sulphate was 49.7 mg kg-1 in top soil and 50.7 mg kg-1 in subsoil while in conventional farm soil sample sulphate ranged: 51.9 (subsoil: 10 – 25 cm depth) – 53.1 (topsoil: 0 – 10 cm depth mg kg-1 (Table 2). In general, in chemical based farming system sulphate is supplied either by inorganic fertilizer or by crop residues after crop residues burning after harvesting. But in organically managed agro-ecosystem industrial fly ash, compost and vermicompost were the major source of sulphate in soils.

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Surendra Suthar, Sushma Singh and Pravin Mutiyar

The calcium and magnesium were relatively higher in organic plot soils as compared to conventional farm (Table 2). The calcium contents ranged 781 (subsoil: 10 – 25 cm depth) – 792 (topsoil: 0 – 10 cm depth) mg kg-1 in organic field soils and 450 (subsoil: 10 – 25 cm depth) – 751 (topsoil: 0 – 10 cm depth) mg kg-1 in conventional farm soils. The magnesium plays an important role in soil metabolism and microbial activities in soil ecosystem. The magnesium content in conventional farm was relatively high (ranged: 154 – 155 mg kg-1 in different soil depths) than organically managed wheat farm (ranged: 152 – 159 mg kg-1 in different soil depths). Major source of these nutrients in soils is irrigated water especially river water irrigations. In general, people do not supply any material to agriculture plots for fulfillment of calcium and magnesium need of the plant, although these materials are required in micro quantity to plants. On the other hand plant residues and other post harvest plant material also acts as another potential source of micronutrients in soils. However, organic fertilizers especially vermicompost contains a significant amount of calcium due to secretion of calcium in vermicomposted material by calcium glands of earthworms. Earthworm mediated mineralization also enhance the level of some mutants like calcium and magnesium in final products (Suthar, 2010). The biological communities usually high in organically managed soils and hence adding of calcium through microflora especially by fugal hypae is also important. The level of available cations (K+ and Na+) in soils was in plots those received organic amendments than chemical based wheat farm. Available potassium content was in the ranges of 106 (subsoil: 10 – 25 cm depth) – 108 (topsoil: 0 – 10 cm depth) mg kg-1 in organic field and 105 (subsoil: 10 – 25 cm depth) – 107 (topsoil: 0 – 10 cm depth) mg kg-1 in conventional farming systems, although different between both farming system was not significant. Sodium in organic farm soils ranged: 109 (subsoil: 10 – 25 cm depth) – 110 (topsoil: 0 – 10 cm depth) mg kg-1 while in conventional farming system its range was slightly higher than organic field soils: 111 (subsoil: 10 – 25 cm depth) – 113 (topsoil: 0 – 10 cm depth) mg kg-1 (Table 2). In general organic fertilizers especially vermicompost and compost contains a great ranges of some readily available plant micronutrients which directly affects not only soil quality but at the same time also influences the overall plant growth.

6. ORGANIC AMENDMENTS AND SOIL HEALTH BUILDING Application of green manure with chemical NPK is a soil building process. It not only buildup the organic matter pool in the soils but at the same time also supply the other macronutrients which in general are not supplied through modern chemical fertilizers. The soil organic pools provides a range of humic acid like substances which directly acts as buffering agents in soils to maintain soil pH. The organically amended soils require lower fertilizer-N to maximize productivity of crops, thus effecting a saving in industrially fixed N. Application of organic amendments alone or in combination with green manure is a carbon sequestrating process. However, residues with wider C:N ratio and high humification co-efficient than green manure possibly leave more C in soil for conversion to soil organic matter (Chhonkar and Rattan, 2000). However, it has been realized that composted organic waste substances may be utilized effectively if mixed with recommended NPK. Such combinations led to enhanced plant uptake capacity. According to Chhonkar and Rattan (2000) the FYMamended alluvial soil requires lower fertilizer-N to maximize productivity of rice-wheat

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Organic Amendments for Agriculture Land Restoration Practices

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system. The soil microbial buildup is another important benefit from continuous application organic amendments in arable lands. Kale et al. (1992) investigated the impact of vermicompost application on soil nutrient quality and microbial population under paddy field crops. They applied half recommended dose of NPK and half in the form of vermicompost. After two month of cultivation there was significant increase in all the groups of microbes except for the actinomycetes in the experimental plot those received vermicompost. In this study micorrhizal colonization was about 14.3 % in experimental plot (1/2 vermicompost + limited N) and it was significantly high than 7.0 % as recorded in control plot (FYM + recommended NPK). Moreover, the symbiotic association of Mycorrhizae in the roots showed a remarkable difference in infection which was just 2.85% in control plots compared to 10% in the experimental plot. Studies have also supported the enhanced soil enzymatic profile after organic amendments in soils. Arancon et al. (2006) studied the influence of vermicompost on soil microbial and chemical properties of soils of strawberries plantations. In this experiment the vermicompost was applied @ 5 or 10 t ha-1 supplemented with inorganic fertilizers NPK. However, soil nutrient contents did not show significant variations between control and experimental plots but soil enzymatic profile and microbial activities varied drastically among plots. Two major results of vermicompost applications to soils were observed: increases in dehydrogenase activity and microbial biomass-N. Increased dehydrogenase activity and microbial biomass-N was correlated positively with the increased amounts of NH4-N, NO3-N and orthophosphates in the vermicompost-treated plots than in the controls. Serra-Wittling et al. (1995) reported increases of dehydrogenase activity in soils amended with compost. They attributed these increases to intense activity of the soil microorganisms in degrading easily metabolizable compounds, with subsequent decreases in activity, attributed to the decreases in quantities of easily biodegradable substances. Similarly, Pascual et al. (1997) have reported significant increases in dehydrogenase activity after amending soil with composts for 8 years compared with activity in unamended soils. The integrated nutrient management including green manure with chemical NPK in combination is a sustainable practice because it synchronizes the nutrient demands set by the plants both in time and space with supply of the nutrients from the labile soil and applied nutrient pools. Cantanazaro et al. (1998) demonstrated the importance of the synchronization between nutrient release and plant uptake and showed that slower release fertilizers (vermicompost, compost, FYM etc.) can increase plant yield and reduce nutrient leaching. Compost/vermicompost could serve as a naturally produced slow release source of plant nutrients. Traditional composts also have agronomic value, but N immobilization (Sims, 1990), salinity effects (O’Brien and Barker, 1996), and pathogen levels (Eastman, 1999) may be problematic. Vermicompost has been appeared as better organic amendment for filed crop than traditional composts. Vinceslas-Akpa and Loquet (1997) compared the effects of composting and vermicomposting and reported that the vermicompost product had a lower C/N ratio, higher protein:organic C ratio, and higher levels of N, which indicates that the vermicompost products were more suitable for soil amendment use. According to Chaoui et al. (2003) in containerized production systems, vermicompost used as an alternative soil amendment could help reduce several problems associated with the use of conventional synthetic fertilizer such as excessive leaching loss of nutrients and salinity-induced plant stress. In addition compost/vermicompost can improve soil porosity, and thus provide a better root growth medium.

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CONCLUSION Adverse effects of chemical-based agricultural practices have been well documented all over the world. Nowadays there is much concern over the introduction of environmentally safe, economically viable and socially acceptable agriculture practices. Organic agriculture is a holistic approach based upon a set of processes that leads to sustainable ecosystem, safe and nutritive food, animal welfare and social justice. Integrated soil nutrient management is an important aspect of organic inputs system. Organic wastes are typically by-products of farming, industrial or municipal activities and they can be used as resource for sustainable land fertility management operations. The soil biological fertility under chemical-based farming system is again issue of concern. The continuous applications of synthetic nutrients in soils have been deteriorating the soil health and soil biological fertility. The supply of SOM in agriculture soils not only restores natural soil detoxification efficiency natural but at the same time helps to buildup the soil biological quality. It is clear that application of organic amendments in cropping system may solve many fold problems of soil degradations and human health safety.

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REFERENCES Arancon, N.Q. Edwards, C.A., Bierman, P. (2006). Influences of vermicomposts on field strawberries: Part 2. Effects on soil microbiological and chemical properties’, Bioresour. Technol. 97, 831–840. Barak P, Jobe, B.O., Krueger, A.R., Peterson, L.A., Laird, D.A. (1997). Effects of long-term soil acidification due to nitrogen inputs in Wisconsin. Plant Soil 197,61 – 69. Bastian, R. K., Ryan, J. A. (1986). Design and management of successful land application system. In: Utilization, Treatment and Disposal of Waste on Land. Soil Science Society of America, Madison, WI, USA, 217-129. Bernal, M.P., paredes, C., sanchez-Monedero, M.A., Cegarra, J. (1998) maturity and stability parameter of compost prepared with a wide range of organic wastes. Bioresour. Technol 63, 91 – 99. Bouman, O.T., Curtin, D., Campbell, C.A., Biederbeck, V.O., Ukrainetz, H. (1995). Soil acidification from long-term use of anhydrous ammonia and urea. Soil Sci. Soc. Am. J. 59, 1488 – 1494. Cantanazaro, C.J., Williams, K.A., Sauve, R.J. (1998). Slow release versus water soluble fertilization affects nutrient leaching and growth of potted chrysanthemum. J. Plant Nutri. 21, 1025–1036. Chhonkar, P.K., Rattan, R.K. (200) Soil fertility management for sustainable agriculture. Indian Farming (2), 26 – 31. Doran, J.W., Parkin, T.B. (1994). In: Defining soil quality for a sustainable environment. SSSA Spec. Publ. 35 SSSA, Madison, WI. Eastman, B.R. (1999). Achieving pathogen stabilization using vermicomposting. Biocycle 40, 62–64. Eck, H.V., stewart, B.A. (1995) manure. In: Rechcigl, J.E. (Ed), Soil Amendments and environmental Quality. CRC Press, Inc., Boca Raton, FL, pp. 169 – 198.

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FAO (2001) Production yearbook. Food & Agriculture Organization (FAO). Rome, Italy7. Fertiliser Association of India (2010), “Fertiliser Statistics 2009-10 and earlier issues”, The Fertiliser Association of India, New Delhi. Hansen, B., Fjelsted, A.H., Steen, K.E. (2001). Approaches to assess the environmental impact of organic farming with particular regard to Denmark. Agri. Ecosyst. Environ. 83 (1-2), 11-26. Hala I. Chaoui1, Larry M. Zibilske2, Tsutomu Ohno (2003). Effects of earthworm casts and compost on soil microbial activity and plant nutrient availability. Soil Biol. Biochem. 35, 295–302. Haynes, J.R., Naidu, R. (1998). Influence of lime, fertilizer and manure application on soil organic matter and soil physical conditions. Nutrient Cycl. Agroecosyst. 51, 123 – 137. Kale, R.D., Mallesh, B. C., Kubra, B., Bagyaraj, D.J. (1992). Influence of vermicompost application on the available macronutrients and selected microbial populations in a paddy field. Soil Biol. Biochem. 24, 1317–1320. Lal, R. (1991). Tillage and Agricultural Sustainability. Soil Till.Res.20, 133–146. Lal, R. (2005) World crop residues production and implications of its use as biofuel. Environ. International: 31, 575 –585. Lal, R. (2007). Farming carbon. Soil Till. Res. 96, 1-5. Lampkin N.H. (1990). Organic farming. Farming Press, Ipswich. Moral, R., Moreno-Caselles, J., Perez-Murcia, M.D., Perez-Espinosa, A., Rufete, B., Paredes, C. (2005). Characterization of the organic matter pool in manures. Bioresour. Technol. 96, 153 – 158. O’Brien, T.A., Barker, A.V. (1996). Evaluation of ammonium and soluble salts on grass sod production in compost. I. Addition of ammonium or nitrate salts. Commun. Soil Sci. Plant Anal. 27, 57–76. Robinson, C.A., Cruse, R.M., Ghaffarzadeh, M. (1996). Cropping systems and nitrogen effects on Mollisol organic carbon. Soil Sci. Soc. Am. J. 60, 264–269. Roldan, A., Salinas-Garcia, J. R., Alguacil, M. M., Caravaca, F. (2005). Changes in soil enzyme activity, fertility, aggregation and C sequestration mediated by conservation tillage practices and water regime in a maize field. App. Soil Ecol. 30, 11 –20. Serra-Wittling, C., Houot, S., Barriuso, E. (1995). Soil enzymatic response to addition of municipal solid-waste compost. Biol Fertil. Soils 20, 226–236. Sims, J.T. (1990). Nitrogen mineralization and elemental availability in soils amended with composted sewage sludge. J. Environ. Qual. 19, 669–675. Smith, P., Falloon, P., Coleman, K., Smith, J., Picollo, M.C., Cerri, C., Bernoux, M., Jenkinson, D., Ingram, J.,Szabo, J., Pastor, L. (1999). Modeling soil carbon dynamics in tropical ecosystems. In: Lal, R., Kimble, J.M., Steward, B.A. (Eds.), Global Climate Change and Tropical Ecosystems. CRC Press, Boca Raton, FL, pp. 341–364. Sombrero, A., de Benito, A. (2010). Carbon accumulation in soil. Ten-year study of conservation tillage and crop rotation in a semi-arid area of Castile-Leon, Spain. Soil Till Res. 107 (2), 64 – 70. Suthar, S. (2007) Nutrient changes and biodynamics of epigeic earthworm Perionyx excavatus (Perrier) during recycling of some agriculture wastes. Bioresour. Technol.: 98, 1614. Suthar, S. (2009). Impact of vermicompost and composted farmyard manure on growth and yield of garlic (Allium stivum L.) field crop’, Internat. J. Plant Prod. 3(1), 1-12.

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Suthar, S. (2010). Potential of domestic biogas digester slurry in vermitechnology. Bioresour. Technol.101, 5419-5425. Swift, R.S. (2001). Sequestration of carbon by soil. Soil Sci. 166, 858–871. Tandon, H.L.S. (1997) Plant Nutrient Needs, Supply, Efficiency and Policy Issues, NAAS, New Delhi, pp. 15 – 28. Vinceslas-Akpa, M., Loquet, M., 1997. Organic matter transformations in lignocellulosic waste products composted or vermicomposted (Eisenia fetida andrei): chemical analysis and 13C CPMAS NMR spectroscopy. Soil Biol. Biochem. 29, 751–758.

In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 4

COMPARATIVE EFFECT OF COMPOSTS AND VERMICOMPOSTS ON P-MINERALIZATION IN LATERITIC SOIL: FACTORS AFFECTING THE PROCESS P. Pramanik1,3 and G. K. Ghosh2 1

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Agricultural and Ecological Research Unit, Indian Statistical Institute, India 2 Department of Soil Science and Agricultural Chemistry, Palli Siksha Bhavana, Institute of Agriculture, Visva-Bharati, Bolpur, India 3 Division of Applied Life Science (BK 21 Program), Gyeongsang National University, South Korea

ABSTRACT In this experiment, composts and vermicomposts of four different organic wastes viz., cow manure, garden wastes, aquatic weeds and municipal solid wastes were applied to the lateritic soil to study its effect on dynamics of P mineralization and also on the various factors of P-solubilization e.g., C/ P ratio and humic acids content, phosphatase activity, microbial respiration, microbial biomass C, biomass P and biomass C/ P ratio of soil. Results revealed that soil organic carbon content was significantly (P < 0.05) increased due to compost and vermicompost application; however, the values were not significantly different. Vermicompost application significantly (P < 0.05) increased available P content of soil which in turn recorded comparatively narrower C/P ratio in these treatments. Except MSW, vermicompost prepared from other treatments registered higher humic acids content than that of composts. Data indicated that vermicompost application significantly (P < 0.05) improved activity of acid phosphatase enzyme, microbial respiration and microbial biomass of lateritic soil. Based on these data, it could be concluded that vermicompost, prepared from garden wastes, was the best treatment to influence different P-solubilizing factors which in turn leads to the comparatively higher available P content in lateritic soil received this treatment. In soil, phosphate solubilizing bacteria produce several organic acids such as oxalic, citric acids and phosphatase enzymes to solubilizing in soluble P.

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P. Pramanik and G. K. Ghosh

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1. INTRODUCTION Lateritic soils are typically low in nutrient content especially in phosphorus (P) and continuous fertilization is required to obtain desired crop yield. Application of inorganic phosphatic fertilizers in soil converts P into secondary insoluble form by combining with iron- and aluminium hydroxyl ions and solubilization of P from these compounds indicates the rate of P-release from fertilizer itself (Brady, 2002). In this perspective, application of organic amendments (compost and vermicompost) has been proved to be comparable to the chemical fertilizers in terms of increasing available P content of soil (Atiyeh et al., 2001). Pramanik et al. (2010) revealed that application of vermicomposts of different organic wastes significantly increased P-availability in lateritic soil and they also improved enzyme activities and microbial status of soil. Both composting and vermicomposting are recycling techniques of solid organic wastes. Composting, the controlled oxidative biological decomposition of organic matter, is an important process for recycling organic substrates. However, composting has some disadvantages such as nutrient loss, cost of land, equipment and labour required for composting and odour is also associated with this process (Eghball et al., 2002). Vermicomposting has been recognized as more eco-friendly technique for converting organic wastes into nutrient-rich amendments. Vermicomposting is the controlled oxidative nonthermophilic decomposition of organic matter by mutual interaction between earthworms and microorganisms (Elvira et al., 1998). In this experiment, comparative effect of composts and vermicomposts, prepared from four different organic wastes viz., cow manure, garden wastes, aquatic weeds and municipal solid wastes, were applied to lateritic soil to study their effect on dynamics of P-mineralization and also on various factors responsible for P-solubilization e.g., C/P ratio and humic acid content, activity of phosphatase enzyme, microbial respiration, microbial biomass C, biomass P and biomass C/P ratio of soil. In this study, definite mechanism of P-solubilization of phosphate-solubilizing bacteria was studied. The objectives were to find the best treatment to increase soil P content and to predict the factor(s), the manipulation of which could improve P-availability in lateritic soil.

2. EXPERIMENT SETUP 2.1. Substrates Used The incubation study was conducted with soil of the agricultural farm of Indian Statistical Institute at Giridih, Jharkhand, India. The area belongs to the eastern plateau region of India having lateritic soils (Aqualfs). The surface soil (0-18 cm depth) was collected and sieved (< 2mm). Some chemical properties viz. pH, EC, water holding capacity, texture (sand, silt and clay percentage), organic carbon (OC), mineralizable nitrogen (N) and available phosphorus (P) of that soil are presented in the Table 1. Vermicomposts and composts of cow manure, grass, aquatic weeds and municipal solid wastes (MSW) were incubated in soil to study the release of nutrients and P dynamics in soil. Some chemical and biochemical properties of those composts and vermicomposts were mentioned in Table 2.

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Table 1. Properties of the soil used for incubation study pH (1: 2.5) 5.35

1

Bulk density (Mg m-3) 1.24

Water holding capacity (%) 37.19

Sand (%) 42.0

Texture Silt (%) 31.7

Clay (%) 26.3

Organic C (%)

Mineral. N (mg kg-1)

Avail. P (mg kg-1)

Acid phosphatase Activity 1

Microbial respiration 3

0.61

148.60

9.759

21.492

0.098

μg p-nitrophenol g-1 hr-1, 2 μg C02-C g-1 d-1.

Table 2. Some chemical and biochemical properties of composts and vermicomposts, prepared from different organic wastes, used for incubation study

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CM GR AW MSW LSD p 0.05 SE (±)

CM GR AW MSW LSD p 0.05 SE (±)

Total organic C CP VC 258.7 241.5 267.9 256.4 262.0 248.3 195.9 186.9 0.45 0.17 Total phosphorus CP VC 9.47 10.53 8.28 9.27 8.08 9.46 6.33 6.91 0.13 0.04

TotaTotal nitrogen CP VC 15.36 17.16 13.85 15.94 12.09 13.40 9.98 10.67 0.13 0.05 SPA CP VC 241.36 243.93 242.58 242.86 245.01 241.36 96.59 81.10 5.83 2.20

CP 16.84 19.34 21.67 19.63

C/N ratio VC 14.07 16.09 18.53 17.52

SMR CP 3.52 2.31 2.58 1.38 0.611 0.231

VC 3.75 3.07 2.94 1.65

CM: cow manure, GR: grasses, AW: aquatic weeds and MSW: municipal solid wastes; CP: traditional compost and VC: vermicompost; SPA: acid phosphatase activity and SMR: substrate-induced microbial respiration; a: mg g-1, b: g p-nitrophenol gm-1 hr-1 and c: µg CO2-C g-1 d-1.

2.2. Soil Incubation Study For the incubation study, composts and vermicomposts were applied at 15 ton ha-1 basis in soil. The experiment was conducted for 90 days with three replications. The moisture content was maintained at field capacity by sprinkling water as and when required. For the estimation of available P content, soil samples were collected at the intervals of 0, 7, 15, 30, 45, 60, 75 and 90 days of incubation. Organic carbon, mineralizable nitrogen, exchangeable potassium content, acid phosphatase activity and microbial properties of soils were estimated initially and at the end of incubation study.

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3. RESULTS AND DISCUSSION 3.1. Soil Chemical Properties Lateritic soils, by the law of genesis, are the most weathered soil. In this type of soil, most of the cations are leached down to the lower soil profiles due to intense mineralization and higher precipitation. That makes the soil acidic in nature. Application of compost and vermicompost shifted the pH (5.35) of the soil towards neutrality (6.5 – 7.5). Soil, received vermicompost of grass, registered the highest pH (pH 7.45) as compared to other treatments (Table 3). The increase in soil pH might be attributed to the insoluble chelate formation of humic acid and humate ions with acid forming cations like Al3+ and Fe3+ (El-Beruni and Olsen, 1979). Application of compost (52-80%) and vermicomposts (47-70%) increased organic carbon (OC) content of lateritic soil after 90 days of incubation (Table 3). Table 3. Chemical properties of soils as affected by composts and vermicomposts prepared from different organic wastes

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pH (1: 2.5, w/v) Compost Vermicompost

7.30 6.65

Compost Vermicompost

7.25 7.45

Compost Vermicompost

6.85 7.05

Compost Vermicompost

6.90 6.75

SE (±)

pH LSD

Organic C (g kg-1) Cow manure 1.524 1.465 Grasses 1.649 1.556 Aquatic weeds 1.607 1.539 MSW 1.391 1.347 Organic C SE (±) LSD

p 0.05

S P SxP

0.203 0.143 0.287

0.411 0.291 0.582

Mineralizable N (mg kg-1)

0.383 0.271 0.542

184.76 189.68

11.735 12.727

134.21 143.60

11.617 12.131

142.63 155.56

11.680 12.378

110.05 133.76

11.549 11.745

Miner. N SE (±) LSD

p 0.05

0.189 0.133 0.267

Available P (mg kg-1)

Avail. P SE (±) LSD

p 0.05

1.081 0.765 1.529

2.195 1.552 3.105

p 0.05

0.362 0.256 0.516

0.734 0.519 1.039

Organic C content of compost-treated soils was comparatively higher than that of vermicompost-treated soils. Addition of organic amendments (composts and vermicomposts) also significantly (P < 0.05) increased mineralizable nitrogen (N) content of soil after 12 weeks of treatment. Irrespective of organic substrates, vermicomposts were proved to be more effective in increasing N-content of soil as compared to traditional compost application. The highest N content was recorded in vermicompost of cow manure, though mineralizable nitrogen content of soil, treated with compost of same organic waste, did not differ

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significantly from that value. Data indicated that N content of soils, received vermicompost of grasses and compost of aquatic weeds, were statistically at par. Phosphorus deficiency in lateritic soils is due to adsorption of phosphorus in the soil rich in sesquoxides (Brady, 2002). Application of compost and vermicompost releases humic and organic acids, which combines with iron and aluminium of soil colloids and thereby reduces phosphorus adsorption (Illmer et al., 1995). Application of composts (17 - 18%) and vermicomposts (18 – 28%) significantly (P < 0.05) increased the concentration of plant available fraction of phosphorus (P) in lateritic soils (Table 3). Application of organic amendments of cow manure recorded the highest available P content in soil. Data revealed that vermicompost, prepared from aquatic weeds, were more effective in increasing available P content of soil as compared to that of grass, though P content of these soils were statistically at par. Application of compost of MSW recorded the lowest P-content in lateritic soil. P-solubilization of organic amendment treated soils might be attributed to the presence of humate and organic anions, which compete with phosphate ions for the ion-exchange sites of soil colloids (Mengel, 1997; Chen, 1995). Changes in soil pH due to earthworm cast and compost application might also be played an important role in solubilization of P in acid soil. However, these effects varied depending on the chemical nature of compost and vermicompost (Chen, 1995). Periodical estimation of available phosphorus (P) content in both compost and vermicompost treated soils revealed an initial decrease in available phosphorus fraction after 7 days of incubation (Table 4). In lateritic soils, where phosphorus is limiting, addition of P in the form of organic amendment stimulates microbial activity (Atiyeh et al., 2000). Due to narrower C/P ratio of added vermicomposts, soil microorganisms accumulate P from inorganic or organic sources at the expense of added organic substrates (Coyne, 1999). During the decomposition of added organic substrates, increase in microbial abundance leads to initial luxury absorption of inorganic P (Enwezor, 2005) and consequently leads to decrease in plant available P fraction of soil. Comparatively higher P-content and narrower C/P ratio of vermicomposts leads to higher mineralization rate in vermicompost treated soils as compared to that of compost-treated soils, which in turn registered higher P-content in earlier treatments. Syers and Springett (1984) also reported comparatively higher rate of Pmineralization in vermicompost-treated soils. Results of this experiment revealed that vermicompost-treated soils recovered their initial P deficiency much faster (after 15 days of vermicompost application) than traditional compost-treated soils (30 days). Thereafter, Pcontent of both the organic amendment-treated soils increased steadily up to about 75 days and then it was stabilized or decreased slightly depending on the nature of treatments. This stationary phase of P-dynamics after 11 to 12 weeks of incubation might be attributed to the insoluble complex formation with iron and alumunium hydroxy-ions present in soil (Kuo, 1990; Begum et al., 2004). The P-dynamics in organic amendment treated lateritic soil revealed three different phases, initial decrease, then extended lag phase, when P-content of soil increased steadily and finally stationary phase. Dependence of soil available P content on total phosphorus (TP) content of incubated organic manures suggested that the rate of phosphorus release depends on the amount of TP present in substrates. Assuming mineralization to follow first order kinetics (r = dC/dt = kC), available phosphorus content of soil was fitted against time of sampling (in days) in the following exponential decay function to obtain the decay constant (k) of organic matter from a linear regression (Breland, 1994)

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P. Pramanik and G. K. Ghosh

Table 4. Dynamics of available phosphorus (mg g-1) in soil as affected by composts and vermicomposts of organic substrates

0 Compost Vermicompost

Compost Vermicompost

Compost Vermicompost

Compost

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Vermicompost

9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37 9.92 ± 0.37

Period of sampling (in days) 7 15 30 Cow manure 9.59 ± 9.94 ± 10.08 ± 0.27 0.18 0.42 9.69 ± 10.27 ± 10.75 ± 0.39 0.36 0.24 Grass 9.43 ± 9.81 ± 10.10 ± 0.44 0.40 0.28 9.55 ± 9.95 ± 10.64 ± 0.51 0.37 0.29 Aquatic weeds 9.50 ± 9.76 ± 10.12 ± 0.28 0.41 0.43 9.67 ± 10.13 ± 10.55 ± 0.51 0.44 0.35 MSW 9.72 ± 9.97 ± 10.25 ± 0.21 0.24 0.33 9.75 ± 10.09 ± 10.39 ± 0.30 0.26 0.19

45

60

75

10.53 ± 0.31 11.39 ± 0.33

11.49 ± 0.41 12.39 ± 0.34

11.74 ± 0.39 12.73 ± 0.33

10.66 ± 0.26 11.12 ± 0.30

11.20 ± 0.37 11.80 ± 0.24

11.62 ± 0.28 12.13 ± 0.26

10.39 ± 0.19 11.21 ± 0.22

11.18 ± 0.33 11.77 ± 0.40

11.68 ± 0.36 12.38 ± 0.41

10.80 ± 0.41 11.01 ± 0.32

10.80 ± 0.36 11.01 ± 0.27

11.55 ± 0.39 11.75 ±0.031

Table 5. Rate of P mineralization (k-values) of rock phosphate amended composts and vermicomposts in soil k-values Cow manure Compost Vermicompost Aquatic weeds Compost Vermicompost

0.0027 0.0033 0.0024 0.0029

k-values Grasses Compost Vermicompost MSW Compost Vermicompost

0.0022 0.0028 0.0023 0.0027

Log (Pt/ P0) = -kt where, Pt = available P content at time t, P0 = available P content of initial soil. For all four types of organic amendments, rate of P-mineralization (k-values) indicated that vermicompost-treated soils hastened the rate of P-solubilization as compared to compost (Table 5). This suggested that application of vermicomposts was more beneficial than traditional compost application in terms of increasing available P content of soil. Humic acids and Psolubilizing bacteria present in the compost play important role to mineralize P for plant

Comparative Effect of Composts and Vermicomposts …

61

uptake. Singh and Amberger (1998) also observed similar findings in wheat straw compost treated soil.

3.2. Phosphatase Activity in Soil Acid phosphatase activity (SPA) was increased due to compost and vermicompost application in lateritic soil (Figure 1). Compost-treated soils had shown higher SPA as compared to that of soils received vermicompost. Comparatively weaker SPA in vermicompost treated soils was probably due to the inhibitory effect of inorganic phosphate ions on SPA (McGill and Cole, 1981). Soils, received organic amendments from cow manure recorded significantly (P < 0.05) higher acid phosphatase activity (41.363 and 43.934 g pnitrophenol g-1 hr-1 for compost and vermicompost, respectively) as compared to other treatments. Soil treated with compost of MSW had the lowest acid phosphatase activity, however, SPA of vermicompost obtained from MSW was significantly (P < 0.05) higher than that of the initial soil (21.492 g p-nitrophenol g-1 hr-1). 47

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Phosphatase activity

45 43 41 39 37 CM

GR

AW

MSW

Treatments CP VC

Figure 1. Acid phosphatase activity (μg p-nitrophenol g-1 hr-1) of soil as affected by composts and vermicomposts of different organic wastes (CP: traditional compost and VC: vermicompost; CM: cow manure, GR: grasses, AW: aquatic weeds and MSW: municipal solid wastes).

Comparison of soil SPA with their available P content of that soil revealed that these two parameters are linearly correlated (r = 0.814*) to each other. However, soil enzyme activity did not show good correlation (r = 0.498) with that of applied organic amendment. Therefore, it could be concluded that phosphatase enzyme of compost or vermicompost did not directly determine the extent of P-solubilization in lateritic soil, though application of these organic amendments increased the enzyme activity of soil, which in turn increased P-solubilization and P-availability in soil. To obtain better idea about source of phosphatase activity and Psolubilizing mechanism in soil, some microbiological parameters were studied and those were discussed below.

62

P. Pramanik and G. K. Ghosh Table 6. Microbial properties of soil as affected by application of compost and vermicompost of different organic wastes

Soil treatments CM GR AW MSW

MBCa CP VC 5.13 5.29 5.78 6.05 5.22 5.41 4.90 5.11

CP 0.69 0.77 0.71 0.63

MBPa VC 0.78 0.84 0.81 0.70

MBP/MBC CP VC 0.135 0.147 0.133 0.139 0.136 0.150 0.129 0.137

SMRb CP VC 0.156 0.166 0.150 0.154 0.169 0.174 0.136 0.149

qCO2c CP VC 30.41 31.38 25.95 25.45 32.38 32.16 27.76 29.16

SMR: substrate-induced microbial respiration and qCO2: metabolic quotient; CP: traditional compost and VC: vermicompost; CM: cow manure, GR: grasses, AW: aquatic weeds and MSW: municipal solid wastes; a: μg g-1, b: μg CO2-C g-1 d-1 and c: μg CO2-C mg-1 MBC d-1.

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3.3. MICROBIAL PROPERTIES OF SOIL Results revealed that vermicomposts were comparatively more effective in enhancing microbial activity than traditional composts (Table 6). Microbial activity was significantly (P < 0.05) increased due to application of both composts and vermicomposts in lateritic soil. The greater pore volume in cast and compost amended soil increases the availability of both water and nutrients to microorganisms (Scott et al., 1996). The highest SMR was observed in soil that received vermicompost prepared from cow manure (0.166 g CO2-C g-1 d-1). Though organic amendments, prepared from MSW, recorded comparatively lower SMR than that of the soil received vermicompost prepared from MSW, SMR of former soil was significantly (P < 0.05) higher than that of initial soil. Higher substrate-induced microbial respiration (SMR) in earthworm cast treated soils was probably due to the presence of different groups of microorganisms in the casts (Chaoui et al., 2003) and release of immobilized nutrients that may have a stimulatory effect on microbial activity and active dormant microbes (Zhang et al., 2000). Soil biochemical processes are significantly regulated by microbial activities. Analysis revealed that SPA of lateritic soils as affected by different compost and vermicompost treatments were significantly correlated (r = 0.787*) to their microbial respiration values. Therefore, extra-cellular secretion of phosphatase enzyme by microbial community is possible the major source of SPA in soil. Since SMR of soil was varied due to nature of applied organic amendments, quality of compost and vermicompost was indirectly controlled the enzyme activity of soil. Microbial biomass carbon (MBC) and phosphorus (MBP) content of soil were estimated in soil initially and after 90 days incubation. Both MBC and MBP were significantly (P < 0.05) increased due to compost and vermicompost application. Results indicated that soil treated with vermicompost of grass had the highest microbial biomass as compared to other treatments and it was followed by vermicomposts of aquatic weeds, cow manure and MSW. Application of traditional composts also significantly (P < 0.05) increased microbial biomass of soil. Metabolic quotient (qCO2), estimated as the ratio of microbial respiration (SMR) to the microbial biomass carbon (MBC), indicates the rejuvenation of the microorganisms in the environment. Analysis revealed that qCO2 of lateritic soil was increased due to vermicompost application. However, qCO2 of soils treated with vermicomposts of cow manure, MSW and aquatic weeds were significantly (P < 0.05) higher than that of grasses, though the values

Comparative Effect of Composts and Vermicomposts …

63

7.5

750

7.0

600

6.5

450

6.0

300

5.5

150

pH

a

5.0

Soluble P (mg/L)

earlier three treatments did not differ significantly (P < 0.05) among them. Higher qCO2 in vermicompost treated soils suggested that vermicompost application not only activated soil inherent microorganisms, but also provided favourable conditions for proliferation of those microorganisms in lateritic soil.

0 0

1

2

3

4

5

Time (days) pH

b

pH

Soluble P

Soluble P

2.0

7.5

7.0

pH

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6.5 1.0 6.0

Growth (A600)

1.5

0.5 5.5

5.0

0.0 0

1

2

3

4

5

Time (days) pH

pH

Growth

Growth

Figure 2. Periodical changes in cell growth, pH and soluble P of R. elymusia culture in M1 () and M2 () media.

3.4. Phosphate Solubilizing Mechanism Results of this experiment revealed that soil microbiota plays an important role in solubilization of insoluble P in soil environment. To describe the phosphate-solubilizing mechanism of soil microorganisms especially of phosphate-solubilizing bacteria (PSB), soil from experimental plot was serially diluted 104 fold with sterile distilled water and 1.0 ml of

64

P. Pramanik and G. K. Ghosh

that soil suspension was spread on Pikovskaya (1948)’s solid agar medium. Bacterial colony was then eluted by inoculating needle and inoculated again in the same broth medium under aseptic condition. Quantitative analysis revealed that concentration of PO4-P in culture medium was increased with increasing cell growth over time (Figure 2a) while the pH of broth medium was dropped drastically with incubation time (Figure 2b). This suggested that PSB produce acids, which have active role in P-solubilization.

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3.4.1. Organic Acid Assay After 5 days incubation at 300C, culture broth medium was centrifuged at 6000 rpm for 15 minutes to separate pellets and supernatant was analysed by TLC for organic acids detection. The mixture of acetone, ammonium hydroxide, ethanol, chloroform and water (30: 11: 5: 3: 1, volume basis) was used as mobile phase for separating organic acids of culture medium. Methyl red (0.25 g) and bromophenol blue (0.25 g) were dissolved in 70% methanol and the resultant solution was used for staining TLC plates (Lee et al., 2001). In this experiment, pure acetic, citric, lactic, oxalic and salicylic acids were used as reference standards. Analysis revealed that presence of lactic, citric and oxalic acids in the culture medium of PSB (Figure 3). The comparative effect of these organic acids was studied on insoluble phosphates like calcium phosphate and rock phosphate. Results indicated that oxalic acid is most effective to solubilize calcium phosphate followed by citric acid and lactic acid while for rock phosphate the order is oxalic acid ≈ citric acid > lactic acid. Researchers proposed that production and release of organic acids is the most probable reason for solubilization of insoluble P (Park et al. 2009). They found the presence of gluconic acid, tartaric acid, formic acid and acetic acid in the culture of Pseudomonas cepacia while Kumari et al. (2008) revealed that oxalic and citric acids are mainly responsible for P-solubilizing activity by endophytic bacteria.

Figure 3. Detection of organic acids in supernatant of R. elymusia broth culture (a: acetic acid, c: citric acid, l: lactic acid, o: oxalic acid and s: salicylic acid, S: broth sample).

2.4.2. Enzyme Assay Phosphatase activity of the five days old culture medium (same culture that used for organic acids assay) was estimated by colorimetric method (Tabatabai Bremner 1969). For measuring activity of acid phosphatase enzyme, p-nitrophenyl phosphate was used as a

Comparative Effect of Composts and Vermicomposts …

65

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substrate and yellow colour intensity of p-nitrophenol was measured at 420 nm. Protein concentration was determined by Lowry method using bovine serum albumin as the standard (Lowry et al., 1951). Results indicated that these microorganisms also produce phosphatase as one of the extracellular enzymes to solubilize insoluble P. Since PSB were isolated from red lateritic soil, only acid phosphatase activity was the main concern during this study. Data (Table 1) revealed that specific acid phosphatase activity of these bacteria in standard Pikovskaya medium was 0.133 μg p-nitrophenol hr-1 mg-1 protein. To purify this phosphatase enzyme, proteins were precipitated in 70% ammonium sulphate solution, redissolved in minimum volume of 50 mM phosphate buffer (pH 8.0) and dialysed against the same buffer for overnight. Ammonium sulphate precipitated proteins had shown 0.215 μg p-nitrophenol hr-1 mg-1 protein specific activity for alkaline phosphatase enzyme with 1.62 fold purification. The dialysed protein solution was then analysed by fast protein liquid chromatography (FPLC) using 50 mM tris-buffer solution (pH 8.0) at a flow rate of 1.0 ml min-1. The retained proteins were eluted with a linear NaCl gradient and total 120 fractions were collected. The fractions were then analysed colorimetrically to obtain the active fraction(s) for acid phosphatase activity. Out of 120 fractions, obtained from FPLC separation of proteins, fractions E7 to E11 (5 fractions) had shown activity of alkaline phosphatase. Among these fractions, E9 had the highest specific enzyme activity with maximum 8.65 fold purification (Table 7). However, overall 6.64 fold purification was obtained after FPLC analysis. Proteins in the enzyme fractions were analyzed by discontinuous sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing PAGE using vertical slab gel electrophoresis unit (the separating gel was 14% acrylamide, pH 8.3 and 5% stacking gel, pH 6.8).

Figure5. SDS-PAGE of crude proteins and isolated alkaline phosphate enzyme from broth culture of R. elymusia(a: crude protein and b: isolated alkaline phosphatase enzyme.

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P. Pramanik and G. K. Ghosh

Table 7. Summary of purification of extracellular alkaline phosphatase enzyme from cultural supernatant of R. elymusia

a

Purification stage

Total activitya

Total proteinb

Crude medium Crude protein solution Fraction E7 Fraction E8 Fraction E9 Fraction E10 Fraction E11 Combined fractions (E7-E11)

80.7 44.9 0.7 1.4 2.3 2.0 1.7 1.59

607.2 208.9 0.9 1.7 2.0 2.6 2.4 1.8

Specific activityc 0.133 0.215 0.778 0.824 1.150 0.769 0.708 0.883

Purification fold 1.62 5.85 6.19 8.65 5.78 5.33 6.64

: μg p-nitrophenol hr-1 ml-1 solution. : mg ml-1 solution. c : μg p-nitrophenol hr-1 mg-1 protein.

b

Proteins were stained using coomassie brilliant blue solution followed by destaining with acetic acid solution. SDS-PAGE analysis of crude protein solution and combined fractions revealed the presence of single enzyme (Figure 4), responsible for solubilization of insoluble P.

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REFERENCES Atiyeh, R.M., Dominguez, J., Sobler, S. and Edwards, C.A. (2000). Changes in biochemical properties of cow manure during processing by earthworms (Eisenia anderi) and the effects on seedling growth. Pedobiologia 44, 709-724. Atiyeh, R.M., Edwards, C.A., Suber, S. and Metzger, J.D. (2001). Pig manure vermicompost as a comonent of a horticultural bedding plant medium: effects on physicochemical properties and plant growth. Bioresour. Technol. 78, 11-20. Begum, M., Narayanasamy, G. and Biswas, D.R. (2004). Phosphorus supplying capacity of phosphate rocks as influenced by compaction with water-soluble P fertilizers. Nutr. Cycl. Agroecosyst. 68, 73-84. Brady, N.C. (2002). The Nature and Properties of Soil. Thirteenth edition. Colier McMillan, London. Breland, T.A. (1994). Enhanced mineralization and denitrification as a result of heterogeneous distribution of clover residues in soil. Plant Soil 166, 1-12. Chaoui, H.I., Zibilske, L.M. and Ohno, T. (2003). Effects of earthworm casts and compost on soil microbial activity and plant nutrient availability. Soil Biol. Biochem. 35, 295-302. Chen, Jen-Hshuan (1995). Effects of organic fertilizers addition on the availability and mineralization of soil phosphorus. J. Chinese Agricul. Chem. Soc. 33, 533-549. Coyne, M. (1999). Soil Microbiology: An Exploratory Approach. Delmar Publishers, New York, 201 pp. Eghball, B., Wienhold, B.J., Gilley, J.E. and Eigenberg, R.A. (2002). Mineralization of manure nutrients. J. Soil Water Conser. 57, 470-473.

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El-Baruni, B., Olsen, S.R., 1979. Effect of manure on solubility of phosphorus in calcareous soils. Soil Science 128, 219–225. Elvira, C., Sampedro, L., Benitez, E. and Nogales, R. (1998). Vermicomposting of sludges from paper-mill and dairy industries with Eisenia andrei: a pilot-scale study. Bioresour. Technol. 63, 205-211. Enwezor, W.O. ( 2005). The biological transformation of phosphorus during the incubation of a soil treated with soluble inorganic phosphorus and with fresh and rotten organic materials. Plant Soil 25, 463-466. Illmer, P., Barbato, A. and Schinner, F., 1995. Solubilization of hardly-soluble AlPO4 with Psolubilizing microorganisms. Soil Biol. Biochem. 27, 265-270. Kumari, A., Kapoor, K.K., Kundu, B.S., Mehta, B.S. (2008). Identification of organic acids produced during rice straw decomposition and their role in rock phosphate solubilization. Plant Soil Environ. 54, 72-77. Kuo, S. (1990). Phosphate sorption implications on phosphate soil tests and uptake by corn. Soil Sci. Society America J. 54, 131-135. Lee, K-Y., So, J-S., Heo, T-R. (2001). Thin layer chromatographic determination of organic acids for rapid identification of bifidobacteria at genus level. J. Microbiological Methods 45, 1-6. Lowry, O.H., Rosebrough, N.J., Farr, A.L., Randall, R.L. (1951). Protein measurement with folin phenol reagent. J. Biological Chem. 193, 265–275. McGill, W.B. and Cole, C.V. (1981). Comparative aspects of cycling of organic C, N, S and P through soil organic matter. Geoderma 26, 267-286. Mengel, H. (1997). Agronomic measures for better utilization of soil and fertilizer phosphates. Eur. J. Agronomy 7, 221-233. Park, J-A. (2010). Isolation and identification of two novel endophytic bacteria from root of halophytes, MS thesis, Molecular Microbial Ecology Laboratory, Division of Applied Life Sciences, Gyeongsang National University, Jinju, South Korea. Park, K-H., Lee, C-Y., Son, H-J. (2009). Mechanism of insoluble phosphate solubilization by Pseudomonas fluorescens RAF15 isolated from ginseng rhizosphere and its plant growthpromoting activities. Lett. App. Microbiol. 49, 222-228. Pikovskaya, R.I. (1948). Mobilization of phosphorus in soil with the vital activity of some microbial species. Microbiologiya 17, 362-370. Pramanik, P., Ghosh, G.K., Chung, Y.R. (2010). Changes in nutrient content, enzymatic activities and microbial properties of lateritic soil due to application of different vermicomposts: comparative study of ergosterol and chitin to determine fungal biomass in soil. Soil Use Manag. 26, 508-515. Scott, N.A., Cole, C.V., Elliott, E.T. and Huffman, S.A. (1996). Soil textural control on decomposition and soil organic matter dynamics. Soil Sci. Soc. America J. 60, 1102-1109. Singh, C.P., Amberger, A. (1998). Solubilization of rock phosphate by humic and fulvic acids extracted from straw compost. Agrochimica 41, 221–228. Syers, J.K. and Springett, J.A. (1984). Earthworm and soil fertility. Plant Soil 76, 93–104. Tabatabai, M.A., Bremner, J.M. (1969). Use of p-nitrophenyl phosphatase for assay of soil phosphatase activity. Soil Biol. Biochem. 1, 301 – 307. Zhang, B.G., Li, T-S., Shen, J-K., Wang, and Z., Sun (2000). Changes in Microbial Biomass C, N and P and Enzyme Activities in Soil Incubated with the Earthworms Metaphire guillelmi or Eisenia fetida. Soil Biol. Biochem. 32, 2055 – 2062.

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In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 5

SUSTAINABLE MANAGEMENT OF LAND AND PEOPLE’S FORESTS IN THE INDIAN EASTERN HIMALAYA: A C&I APPROACH G. Pangging1, Kusum Arunachalam2 and A. Arunachalam3

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1

Department of Forestry, North Eastern Regional Institute of Science and Technology, Nirjuli, Arunachal Pradesh, India 2 School of Environment and Natural Resources, Doon University, Dehra Dun, Uttarakhand, India 3 Division of Natural Resources Management, Indian Council of Agricultural Research, New Delhi, India

ABSTRACT The criteria and indicators (C & I) have become a new revolution in assessing the sustainable forest management that has been a focal point in the forest principle of agenda 26 of Rio Earth summit. Though Bhopal-India process has evolved with C&I for the Indian forests, certain inclusions are needed to be made for more appropriate application in northeast Indian forests that form part of the Indo-Burma mega biodiversity hotspot in the eastern Himalaya. The pattern of land ownership and traditional knowledge systems and the role of informal institutions in forest management make this region unique from rest of the country. After appropriating the C & I developed through BhopalIndia process and that of Ahmad (2004), we have arrived at 10 feasible C & Is for the Indian eastern Himalayan region. Over all, the C & I feasibility was tested based on the human values that are attributed with ecology, economics and ethics in the context of socio-ecological and institutional linkages for natural resource management and environmental conservation in the biodiversity rich north-eastern hilly region of India.

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G. Pangging, Kusum Arunachalam and A. Arunachalam

CRITERIA and Indicators (C&I) are considered as the assessment tools to sustainable forest management (SFM) globally. This concept tends to balance the three important aspects of sustainable development viz., ecology, economics and ethics. This initiative has started in the 20th century and various organizations have developed C&I to assess SFM. Forest Steward council (FSC), International Timber Trade Organizations (ITTO), Pan European Forest process and other nation’s certification processes have been a few such initiatives, by which millions of hectares of forest area have been brought under sustainable forest management. Earlier, the Indian Institute of Forest Management (IIFM, Bhopal, India) took the lead in developing 8 criteria and 51 indicators for sustainable forest management at the national level and launched the Bhopal-India Process in 1998 (Cheng and Durst, 1999). Recently, Ahmad (2004) evaluated the feasibility of Bhopal-India process, and modified and reframed the C&I for all forest types making more a system specific/agro-climatic zone specific. Table 1. Number of C&I of different forest classes

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Sl. No. 1. 2. 3. Source: Ahmad, 2004.

Forest Class Production forest Protected forest Community forest

Criteria 4 6 6

Indicators 15 30 29

In India, C&I (Bhopal-India Process) has been developed recently by the Indian Institute of Forest Management (IIFM), wherein 8 criteria and 51 indicators have been identified to assess the SFM of Indian forests. Recently, cross analysis has been done by Ahmad (2004) to assess the feasibility of C&I on three different forest classes i.e., production forest, protected forest and community forest (Table 1). It is found that differential C&I are suitable for different forest classes to assess the SFM. Although comparable set of criteria and indicators have been found suitable for management of community forests and protected forests (Table 1), certain analyses are still needed to condition the complex biodiversity rich landscape such as in the Indian eastern Himalaya, where most forests are owned by private or by clan. As such, the natural resources have been traditionally managed by communities from time immemorial, besides such efforts from the forest department. In the eastern Himalayan region, people’s interdependence of forest resources have resulted in various forms of forested zones such as private forest, clan forest and community forest. The ‘modus operandi’ for managing these forests includes concerns of protection and meeting the needs for self-sustenance as well. In most cases, production is not the sole objective of managing forest. Nevertheless, inventory of forest resources for commercial purposes are observed nowadays that may even deteriorate the quality of forests both structurally and at functional levels. Thus, ecological economics in relation to resources utilization need to be considered while assessing the sustainability of forests (Arunachalam et al., 2003).

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Sustainable Management of Land and People’s Forests …

Figure 1. Selected forested systems managed by tribal societies in north-east India; (A) Sacred grove, (B) Agro-forest, (C) Community forest.

Table 2. The type of forest and mode of function Sl. no 1. 2. 3.

Forest Sacred Forest (SF) Forest managed by tribal people (CF) Agro-forestry (AF)

Protection √ √

Production X √

Conservation √ √

√

√

X

71

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G. Pangging, Kusum Arunachalam and A. Arunachalam

Evidently, large areas have been brought under village forests that are primarily community-managed with vibrant customary practices. We have delineated 3 types of tree cover systems (Figure 1) namely agroforests (AF) (Upadhyaya et al., 2005), sacred forest (SF) and forests managed by tribal people i.e. community forest (CF). Their primary functions have been documented in Table 2; the agroforests had production function (Tanjang et al., 2004) and sacred forests are embedded with conservation values (Arunachalam et al., 2004). We have attempted to screen and identify various C&I that could apply to AF, CF and SF to have coordinated efforts for SFM. Nevertheless, the enactments of customary law/rules, which is a dynamic in the northeast Indian states, village council plays a vital role in management of forest through enactment of customary laws (local rules and regulation) (Box 1). Evidently, large areas of forests are community managed (Sarmah et al., 2004). Some relevant communities are Mangmajom in the monpa community, Thiko or Jung in Sherdukpens, Mimiang in Miji, and Malley or Riaz in Akas (Hegde, 2002). Box 1.

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Customary law – The local governance systems exist since time immemorial, which consist of chieftaincy system, gerontocracy, democratic and arbiter system (Hedge, 2002). The rules and regulations are the uncodified laws that have been followed by the tribal communities that play an important role in conservation as well as management resources. Although formal institutions are in place, the customary law is still respected in the decision making process of most tribes living in the Indian eastern Himalayan region. Keeping in view the complexity of forest and its management in the ecologically fragile Indian eastern Himalayan region, there is an urgent need to undertake feasibility testing of C&I as identified for the India forests for their appropriateness in managing the least studied north- eastern hill forests in particular. And then efforts to modify and/or update the C&I to enhance the management of forest in a sustainable manner in this “Mega Biodiversity Global Hotspot” needs a process that should balance ecological efficiency with economic returns to catalyze and perpetuate human values. Thus we prescribe to the C&I formulation for the Indian eastern Himalayan region considering the following points: 1. Ownership of forests viz., private forest, clan forest and community forest. As such, there is no land use policy in any of the states. 2. Dynamics of customary law and social transformation. 3. Traditional ecological knowledge systems and resource conservation. 4. Alternative income generation activities e.g. apiculture, sericulture, pisciculture, etc. 5. Traditional institutional linkages and livelihood management. Nonetheless, the indigenous communities are moving away from traditional practices due to advent of modernization and life style synchronization of a forest dependent livelihood has been in swept off (Arunachalam et al., 2001).

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Table 3. Appropriating criteria and indicators of Ahmad (2004) in identified forested systems in northeast India S. No 1.

2.

3.

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4.

5.

Criteria Increasing Forest Cover (i) Percentage of forest cover (including tree cover & grasslands) in relation to geographical area. (ii) Percentage degraded area, in relation to total forest area Conservation of Ecosystem Vitality & Biodiversity (i) Percentage of budget availability w.r.t. annual requirement according to Management Plan (ii) Regular analysis of Population estimation & behavior (iii) Grazing area Percentage (iv) Weed infested area Percentage (v) Percentage of area affected by fire (vi) Incidence of outbreak of diseases (vii) Removal of forest produce ( both permissible & illicit) (viii) Percentage of tourism area (ix) Percentage of tourists who, regarding the Ecosystem Vitality & Biodiversity are satisfied by their visit: (x) Percentage of forest produce removed within sustainable limits going for direct consumption by the surrounding communities. Soil & Water Conservation (i) Percentage of eroded area (ii) Number of perennial streams from the forest (iii) No. of 5 km. x 5 km. quadrants in which there is no natural waterhole in pinch period Enhancing Productivity (i) Growing stock of wood, animals and other marketable produce (ii) Percentage of removal of forest produces W.R.T. sustainable production (iii) No. of seed orchards, seed productivity areas & good breed animals (iv) Revenue from tourism Meeting the basic needs of communities through Eco-compatible activities (i) Percentage of families not using synthetic fertilizers & pesticides (ii) Percentage of locally produced crop consumption W.R.T. the annual need (iii) Percentage of fuel wood, fodder and small timber requirements produced from plantation on field bunds, courtyard and other private lands (iv) Percentage of families aware and practicing natural health care systems (v) percentage of family aware and practicing natural health care systems (vi) Man days generated by eco-tourism & other forestry activities (vii) Percentage of tourism revenue going for eco-development activities

AF

CF

x

√

x

SF √ √

x

√

√

x √ √ √ √ √ x x

√ √ √ √ √ x √ √

√ x √ √ √ x √ √

x

√

x

√ √ x

√ √ √

√ √ √

√ x

x x

x x

x √

x x

x x

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√ x

√ √

√ √

74

G. Pangging, Kusum Arunachalam and A. Arunachalam Table 3. (Continued)

S. No

6.

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7.

Criteria (viii) Literacy Percentage (persons educated up to primary level) (ix) Percentage of families adopting family planning schemes Increasing Participatory Status (i) No. of Committees (ii) Percentage of Committees with role based sub committees (iii) Participatory status Increasing Managerial Sensitiveness (i) Percentage of claims of staff disposed off within stipulated time (ii) Percentage of essential facilities provided to staff (iii) Percentage of claims of the public disposed off according to citizens charter (iv) Percentage of right to information cases disposed off within stipulated time

√ √

AF √ √

CF

SF √ √

x x x

√ √ √

√ √ √

x x x

x x x

x x x

x

x

x

Presently, the society is more agrarian than forest dependent. Further, growing feathery ideas of cash cropping, mining, jatropha cultivation, medicinal and aromatic plant cultivation are also threatening the human values that were more attributed with forests where services to humankind are generally invisible. In spite of own great efforts, we have not been able to restore any degraded forest particularly from animal diversity view point. Therefore, it is all the more important that a robust model linking rural Panchayat Raj Institutions to other formal and informal institutions for SFM be drawn through feasibility testing and appropriate evaluation of C&I for SFM, particularly in the floral and faunal resource rich areas of northeast India. Therefore, we have appropriated the application of the C&I system by Ahmad (2004) and Bhopal-India Process (Tables 3, 4) in the context of the biodiversity rich Indian eastern Himalayan region. Table 4. Appropriating criteria and indicators of the Bhopal-India Process with the forested systems practiced by tribal societies in the north-east India S.No 1.

2.

3.

Criteria Extent of forest and tree cover 1.1 Area and type of natural and manmade forests. 1.2 Forest area under fragile ecosystems. 1.3 Area under dense and degraded forest. 1.4 Forest in non-forest area. 1.5 Area rich in NWFP species. 1.6 Forest area diverted for non-forestry use. 1.7 Community managed forest areas. Ecosystem function and vitality 2.1 Status of natural regeneration. 2.2 Status of natural succession. 2.3 Weed pest, diseased, grazing, fire, etc. Biodiversity conservation

AF

CF

SF

X X X X √ X √

√ √ √ √ √ √ √

√ √ √ x √ x x

√ X √

√ √ √

√ √ √

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4.

Criteria 3.1 Area of protected and fragmented ecosystems. 3.2 Number of rare, endangered, threatened and endemic species including tiger population. 3.3 Level of species richness and diversity. 3.4 Canopy cover. 3.5 Medicinal and aromatic plants and other NWFPs. 3.6 Level of non-destructive harvest. Soil and water conservation 4.1 Soil moisture. 4.2 Soil compaction. 4.3 Status of erosion. 4.4 Run-off (water yield)

4.5 Soil pH. 4.6 Soil organic carbon. 4.7 Nutrient status of the soil. 4.8 Soil flora, fauna and microbes. 4.9 Level of water Table. 4.10 Sediment load. 5. Forest resource productivity 5.1 Growing stock of wood and non-wood forest products. 5.2 Natural regeneration status. 5.3 Increment of wood and non wood products. 5.4 Area of afforestation and new plantations. 5.5 Level of material and technological inputs. 5.6 Extent of protection measures. 5.7 Level of tangible benefits. 6. Forest resources utilization 6.1 Aggregate and per capita wood and non-wood consumption. 6.2 Import and export of wood and non-wood forest products. 6.3 Recorded and unrecorded removals of wood and non-wood forest products. 6.4 Direct employment in forestry and forest industries. 6.5 Contribution of forest to the income of forest dependent people. 7. Social, cultural and spiritual needs 7.1Well-being in terms of livelihood, recreation, cultural and aesthetic needs. 7.2 Degree of economic, social, gender and participatory equity. 7.3 Conflict management mechanisms. 7.4 Traditional (Indigenous) Knowledge application. 8. Policy, legal and institutional framework 8.1 Existing policy and legal framework. 8.2 Extent of community, NGO and private sector participation. 8.3 Investment in research and development. 8.4 Human resources capacity building efforts. 8.5 Forest resource accounting. 8.6 Monitoring and evaluation mechanisms. 8.7Status of information dissemination and utilization. √ - feasible; x – not feasible.

75

AF X X

CF √ √

SF √ √

√ √ √ √

√ √ √ √

√ √ √ x

√ √ √ √

√ √ √ √

√ √ √ √

√ √ √ √ √ √

√ √ √ √ √ √

√ √ √ √ √ √

√ √ √ √ √ √ √

X x X √ √ √ √

x √ x x x √ x

√ √ X

√ √ X

x X X

√ X

X √

X X

√

√

√

√ √ √

√ √ √

√ x X

X √ √ √ X X X

X √ √ √ X X X

X √ √ √ X X X

76

G. Pangging, Kusum Arunachalam and A. Arunachalam Table 5. Feasible C&I for different forest in the Indian eastern Himalaya

S. No

Forest

1. 2. 3.

AF CF SF

C&I of Ahmad (2004) Criteria Indicators 6 17 6 26 6 24

C&I of Bhopal-India process Criteria Indicators 8 35 8 40 8 29

It is observed that 6 criteria developed by Ahmad (2004) have been found suitable to study the feasibility of sustainable forest management wherein 14, 26 and 24 indicators have been found to suitable to AF, CF and SF, respectively (Table 5). In appropriating the feasibility of C&I developed by the Bhopal-India process to the northeast Indian forests, it has been found that 8 criteria are feasible for all the forest types, and 35, 40 and 29 indicators shall be suitable for agro-forest, community forest and sacred forest, respectively. The study revealed that there are about six criteria found common between C&I as recommended by Ahmad (2004) and Bhopal-India process (as shown in Table 4 and 5). They are as follows: 1. Forest and tree cover 2. Ecosystem function and vitality 3. Biodiversity conservation 4. Soil and water conservation 5. Forest resource productivity 6. Forest utilization

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Out of the uncommon criteria found between these two C&I processes, 4 criteria have been found suitable to the eastern Himalayan region. They are as follows: 1. 2. 3. 4.

Meeting the basic needs of communities through eco-compatible activities Increasing participatory status Social, cultural and spiritual needs Policy, legal and institutional framework

Thus by incorporating the common and uncommon criteria found from the C&I process (Table 4 and 5), 10 criteria have been found to be suitable to assess the SFM of the aforesaid forests (AF, CF and SF). Despite of C&I developed by the Ahmad (2004) for three categories of forests, there is an urgent need to modify C&I to make it more relevant for the eastern Himalaya. In case of Bhopal-India process, emphasis has been given to all types of forest wherein the traditional (indigenous) knowledge applications (as shown in indicator 7.4) have been given emphasis. However there can be more inclusions of factors based on the prevailing sites to make it more applicable to northeast in general and eastern Himalaya in particular viz., the ownership of forest, application of customary laws, alternative income generation activities e.g. apiculture, sericulture, pisciculture, etc. and traditional institutional linkages & livelihood management.

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Table 6. Significance of different forest systems managed by the tribal societies S. No 1

2

3

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4.

Parameters Structural parameters Biodiversity Plants Animals Tree diversity Canopy cover (approx.) Functional parameters Biomass/carbon Soil and water conservation Nutrient cycling Production Utilisation Socio-cultural parameters Food-security potential Human values Economics Cultural needs Spiritual needs Institutional involvement Participatory status Involvement of traditional institution Customary law

AF

CF

SF

Low Low Low Open

Medium-High Medium – High High Closed

High High High Closed

Low Moderate Closed High High

More High Open Low Low

More High Open Low Low

High Moderate High Medium Low

Low – Moderate High Moderate High Low

Low High Low High High

High Low Low

High High High

High High High

The aforesaid criteria have shown significant role in the forest systems managed by the tribal communities (Table 6). Over all, the sacred forests and community forests registered greater values attached with tribal societies based on the socio-ecological and institutional linkages with traditional knowledge systems. In conclusion, the present theoretical C & I analysis for the Indian eastern Himalayan region warrants further in-depth pilot study on feasibility analysis of C & I as suggested by the Bhopal-India Process and also that of Ahmad (2004) that could be quantified through field samplings. The study expectedly evolve a policy document that could help in sustainable management of the biodiversity rich forest/vegetation that has much more invisible goods and services to human livelihood and sustenance in this green planet.

REFERENCES Ahmad, S. (2004). Criteria and Indicators for Good Forest Management. Paper material in International Training Programme on Forest Certification, Garpenberg, Sweden. http://www.ssc-forestry.com/fc04/files/material/material/Criteria_Indicator_good_forest_ management.pdf.

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Arunachalam, A., Melkania, U., Arunachalam, K. and Ghosh, G. (2001). Protected area management in Arunachal Pradesh: Issues and options for biological conservation. Himalayan Biosphere Reserves, 3 (1&2): 62-66. Arunachalam, A., K. Arunachalam, Adhikari, D., Sarmah, S and Majumder, M. (2003). Biotic pressure on forest resources in and around Namdapha national park, Arunachal Pradesh, India. Arunachal University Research Journal, 6 (1): 250-266. Arunachalam, A., Arunachalam, K. and Khan, M.L. (2004). Significance of sacred groves in sustainable development of northeast India. In: (P.K. Singhal and P. Shrivastava, Eds.) Challenges in Sustainable Development, Pp. 64-73 (Chapter 5), Anmol Publications Pvt. Ltd., New Delhi. Cheng L.T and Durst, P.B. 1999. Asia-Pacific Forestry Commission. Development of National-level Criteria and Indicators for the Sustainable Management of Dry Forests in Asia: Background Papers. Bhopal, India 30 November-3 December 1999. Hegde, S.N. 2002. Arunachal Pradesh State Biodiversity Strategy and Action Plan (Final Report). State Forest Research Institute, Arunachal Pradesh, Itanagar. Sarmah, R., Adikhari, D., Majumder, M., Arunachalam, A., Upadhyaya, N., and Tapasvi, S. (2004). Institutional Arrangement for Forest Management in Arunachal Pradesh: A Case Study from Namdapha National Park. Arunachal University Research Journal, 7 (1): 1526. Tanjang, S., Deb, S., Arunachalam, A., Melkania, U., Arunachalam, K., Shrivastava, K. and Brahma, S. (2004). Tribal communities and vegetational characteristics in traditional agroforestry systems of northeast India. Indian Journal of Agroforestry 6(1): 73-80. Upadhyaya, K., Arunachalam, A., Arunachalam, K. and Joshi, R.C. (2005). Traditional homestead agroforestry in Tawang: A prospective land use system for the high mountains. Arunachal University Research Journal, 8 (2): 21-29.

In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 6

LANDSCAPE STABILITY EVALUATION BY LANDSCAPE GEOMORPHOLOGIC DYNAMICS (LGD) ASSESSMENT: PLANNING AND MANAGING LANDSCAPES Selma Beatriz Pena1,* and Maria Manuela Abreu2

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1

Centro de Estudos de Arquitectura Paisagista “Prof. Caldeira Cabral”, Instituto Superior de Agronomia, Universidade Técnica de Lisboa (TULisbon), Tapada da Ajuda, Lisboa, Portugal 2 Unidade de Investigação de Química Ambiental, Instituto Superior de Agronomia, Universidade Técnica de Lisboa (TULisbon), Lisboa, Portugal

ABSTRACT A landscape is an open system that comprises several natural and cultural subsystems standing in interaction. Among those subsystems, energy and matter flows in a dynamic equilibrium or disequilibrium. The methodology applied to measure the equilibrium/disequilibrium of landscapes considers the morphogenesis/pedogenesis rate. This rate embraces the assessment of interdependent processes that model landscape – Landscape Geomorphologic Dynamics (LGD). With this approach, it is possible to distinguish between stable and unstable landscapes. Landscape Geomorphologic Dynamics assessment evaluates landscape stability in four main classes: Pedogenesis, Morphogenesis, Intergrade to Pedogenesis and Intergrade to Morphogenesis. According to this method, if the trend is for morphogenesis, landscape will evolve towards disequilibrium. Otherwise, if it is to pedogenesis, landscape evolution will reach a (dynamic) equilibrium. The pedogenesis concept includes processes that lead to soil formation, and consequently to biomass production, CO2 sequestration and energy conservation. Morphogenesis occurs in locales with high morphodynamic activity, leading to soil loss by erosion and insufficient vegetation growth. The intergrade areas are those which are approaching stability or instability. *

E-mail: [email protected].

80

Selma Beatriz Pena and Maria Manuela Abreu Landscape Geomorphologic Dynamics assessment was carried out with data collection from observation and interpretation of landscapes by field work using geological, topographic information and orthophoto maps. In the field work, erosion factors, rock weathering, vegetation cover density, soil depth and agricultural practices were evaluated. After data collection, this information was integrated into a Geographic Information System. As a result, Landscape Geomorphologic Dynamics assessment allowed for diagnosing landscape stability. With this analysis, it was possible to achieve a framework for promoting the dynamic equilibrium of landscapes. Therefore, LGD in conjunction with other planning instruments such as ecological networks can lead to accomplishing priority intervention actions with management measures of recovery, conservation and redevelopment of land uses. This methodology was studied in several municipalities of the Lisbon Metropolitan Area (Portugal). The present study cases include the municipalities of Sintra and Almada. In these study cases, it was possible to identify the advantages of LGD assessments in planning and managing landscapes.

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1. SCOPE OF THE REVIEW Landscape Geomorphologic Dynamics (LGD) Assessment has as its main goal determining landscape stability or instability in a specific geographical area, within a period of time t. Through this assessment, it is possible, according to the interaction between natural and cultural factors, to predict how the landscape will tend to evolve. This will allow for establishing priority actions for geomorphological stabilisation. This knowledge, in articulation with the ecological network, will permit understanding: (1) landscape geomorphological stability of an ecological network; (2) management measures that should be prioritised to achieve ecological network stability. This chapter describes the Landscape Geomorphologic Dynamic Assessment methodology based on the concepts expressed since 1948 by the geographer-geomorphologist Jean Tricart, and developed in the R&D unit «Centro de Estudos de Arquitectura Paisagista – “Prof. Caldeira Cabral”» from the Technical University of Lisbon (TULisbon) (Abreu et al., 2003; 2007; Magalhães et al., 2003; 2005; 2006; 2008). The LGD assessment methodology was applied in two study cases, the Almada and Sintra municipalities, with the development of LGD management plans.

2. INTRODUCTION Landscape is defined in the European Landscape Convention (Council of Europe, 2000) as “an area perceived by people, whose character is the result of the action and interaction of natural and/or human factors”. Accordingly, landscape is a heterogeneous area composed of a cluster of interacting ecosystems (Barnes, 2000). Considering ecosystems as open systems, which are open for mass and energy transfer (Jorgensen & Svirezhev, 2004), landscape is a complex open system (Magalhães, 2001), comprising several ecosystems (including cultural systems) standing in interaction with themselves and with each other, in a dynamic and

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81

balanced interaction (Figure 1). Understanding the natural and cultural interrelationships constitutes a first step towards achieving landscape sustainability (Pena et al., 2010).

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Figure 1. General interactions between landscape components.

However, this balanced interaction can be easily broken when one (or more) landscape components is disturbed. Normally, humans can have a negative (or positive) action on landscape, but natural hazards can also unbalance the system (earthquakes, floods, etc.). Energy sources in a landscape system include the energy coming from the interior of the Earth (tectonics and volcanism), gravity and solar energy (Tricart, 1972). All this energy is key to all processes that take place in the lithosphere. The environmental conditions for life support results from the interactions between atmosphere-hydrosphere-lithosphere-biosphere. The adjustments of these dynamic systems to new conditions which generate disequilibrium occur mostly in the biosphere (Tricart, 1972). These interactions between subsystems occur within a defined space through time – landscape is always changing. The scientific study of landforms and the processes that sculpture them as well as the time evolution of these processes have been the target of geomorphology studies. In the history of geomorphology, the Davisian cycle was the first theory which intended to explain landform evolution. In this theory, the earth’s landforms were all closely interrelated, forming parts of an evolutionary sequence (Huggett, 2003; Small, 1970). In the beginning of the 20th century, a new theory of landform evolution arose – the dynamic equilibrium theory. This theory was first developed by Penck, Hack, Strahler, Chorley and Tricart (Huggett, 2003; Small, 1970). The dynamic equilibrium theory assumed that all features (components) of a landform, as well as the processes, are related to each other in a condition of energy balance in an open system (Bull, 1991). The same theory points out that those components will be subject to morphological adjustments if the energy balance is modified. Unlike the Davisian cycle, the Dynamic Equilibrium Theory considers that when landscape changes do occur, they do not always result in landforms evolving in the same direction towards an inevitable form. Instead, landforms will only go through adjustments to meet the requirements of new conditions (Bull, 1991; Christofoletti, 1980; Small, 1970). The Dynamic Equilibrium theory is the background concept of Landscape Geomorphologic Dynamics (LGD) assessment. In each instant, landscape evolution tends towards a dynamic equilibrium state in order to achieve ecological system stability.

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However, over a certain period of time, landscape can be in different evolutionary stages that will range from imbalanced to balanced situations in which ecological stability/sustainability has been achieved (Abreu et al., 2007). In the latter situation, landscape is in dynamic equilibrium. The degree of stability or instability of a landscape, at a certain time t, is determined by landscape geomorphologic dynamic analysis. This is carried out through the study of the morphogenesis/pedogenesis rate that characterises the landscape in four main states: Pedogenesis, Morphogenesis, Intergrade to Pedogenesis and Intergrade to Morphogenesis (Tricart, 1965; 1994). The different states of landscape evolution are evaluated qualitatively by cartography analysis and field work. The pedogenesis concept involves all processes that lead to soil formation and, consequently, by means of vegetation, to biomass production, energy conservation and CO2 sequestration. In contrast, the morphogenesis state is a result of erosion processes leading to soil loss, decreased soil formation and insufficient vegetation growth. These processes are energy wasting and result in actual landscape disruption and destruction. The intergrade landscape states between pedogenesis and morphogenesis represent an intermediate stage in which the landscape dynamic approaches stability or instability, respectively (Pena et al., 2010). Some studies have been made based on geomorphologic dynamic theory, especially in Brazil where Tricart had a profound influence. Areas susceptible to degradation have been assessed (fragility degree) in order to plan activities that restrict and direct land use to prevent and minimise problems related to environmental quality (Amaral & Ross, 2009). The comprehension of environmental sensitivity can give way to sustainable development (Cloquell-Ballester et al., 2008) by supporting decisions regarding interventions from ecological, economic and social perspectives (Pena et al., 2010).

3. LANDSCAPE GEOMORPHOLOGICAL DYNAMICS ASSESSMENT: MORPHOGENESIS/PEDOGENESIS RATE 3.1. Morphogenesis/Pedogenesis Rate Landscape Geomorphological Dynamics assessment is based on the Morphogenesis/ Pedogenesis rate evaluation. Morphogenesis is a set of processes leading to landscape change and degradation. The morphogenesis evolution state is the result of the interactions that occur among landscape components defining actual landscape modifications. This set of landscape component interaction lead to mass and energy loss. The result is soil erosion (accelerated erosion or sometimes also known as anthropic erosion) or the maximisation of geological erosion (natural erosion). The pedogenesis state leads to landscape conservation through energy capture and conservation (biomass production), soil genesis and minimisation of geological erosion. The balance between pedogenetic and morphogenetic processes that together, but with different intensities, are occurring in a landscape determines whether the landscape is in equilibrium (a steady state) and therefore ecologically stable or in disequilibrium (unstable). Thus, it is possible to assess which areas are suitable for a specific land use and what priority

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actions should be implemented in order to deter landscape instability and to promote ecological equilibrium. Landscape balance is defined in terms of dynamic equilibrium occurring in an open system in which there are import and export of energy and matter through an adjustment of the system itself (Christofoletti, 1980). Stable landscape situations (pedogenesis) are those where the morphogenesis/ pedogenesis rate favours pedogenesis (Tricart, 1962; 1994). They are characterised by slow geomorphologic evolution which is not perceptible over short time intervals. Unstable landscape situations (morphogenesis) are characterised by the prevalence of morphogenesis over pedogenesis processes. This situation leads to landscape degradation by facilitating accelerated erosion (soil erosion) and/or geological erosion. Compared to pedogenesis, morphogenesis processes occur at a very rapid rate. Besides the stability or instability of landscape states, the intermediate stage (intergrade states) between morphogenesis and pedogenesis must also be considered. This evolution state of the landscape can show a tendency towards morphogenesis (intergrade to morphogenesis) or toward pedogenesis (intergrade to pedogenesis). The morphogenesis/pedogenesis rate is also based on the principle that acts vertically under the effect of water infiltration, and morphogenesis takes place tangentially to the surface flow by the erosion processes (Tricart, 1994). Water infiltration enriches the soil with the circulation of chemical elements, allowing biogeochemical cycles to proceed. It is possible to establish, at a given time t, the variation of pedogenesis and morphogenesis according to different land morphologic/topographic locations (Tricart, 1994). Combined with the interpretation of landscape morphology, based on wet system and dry system concepts (Magalhães, 2001), it is possible to distinguish the rate of morphogenesis and pedogenesis which influence landscape morphology (Figure 2). A dry system comprises the summit, the hillside slope and the footslope: the summit is a flat surface where material accumulation does not occur (no sedimentation occurs); a hillside slope is a zone of the landscape where material export occurs; in the footslope zone, material accumulation takes place. The wet system is represented by the flat surface of the valley subject to aeolian or fluvial accumulation (sedimentation). Summits are flat or gently waved surfaces and, due to its topographic position, are not subject to the accumulation of materials. In these areas, the materials flow tends to be null and a tendency for water infiltration is observed. In this zone, there is a marked prevalence of pedogenesis processes. Matter flow is influenced by slope as the materials are largely exported through the hillside slope. In general, higher slopes are associated with greater gravitational energy. Consequently, there is a high probability of mass wasting. On steeper slopes, besides the increase of gravitational energy, kinetic energy also increases; the runoff becomes faster and removes the superficial soil horizon which is, for the majority of soils, an organic horizon. Organic matter leads to a better soil structure which promotes water infiltration into the soil. With the ablation of this horizon, soil fertility decreases and erosion process become even more intense, progressing to deeper horizons with consequent mass wasting even progressing to the bedrock. However, if vegetation is present, resulting in an efficient soil surface cover, erosion processes could be strongly decreased.

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Selma Beatriz Pena and Maria Manuela Abreu

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Figure 2. Morphogenesis (M) and Pedogenesis (P) prevalence (indicated by the vectors) in different landscape morphology locations.

At the footslope, there is a tendency for material accumulation. Organic materials as well as inorganic materials resulting from slope denudation are displaced and deposited in the foothills. The surface soil horizon becomes thicker and is enriched; consequently, pedogenesis is favoured. However, even in places where wind and fluvial sediment deposition occurs, morphogenesis can be favoured. In fact, Tricart (1972) states that in some areas corresponding to flood plains, terrace deposits or areas of wind sediment accumulation, deposition can be faster than pedogenesis processes. Contrary to the foot-slope, in this zone, the soil horizons rich in organic matter can be covered with less reactive and poorly nutritional inorganic materials, whose capacity to support life is small. But, between two deposition stages, pedogenesis processes can take place if favourable conditions occur. On those flat surfaces pedogenesis or morphogenesis processes may have an equal probability of occurrence.

3.2. Morphogenesis Morphogenesis represents the disequilibrium of the landscape system: adverse conditions for life, energy consumption and degradation of the present landscape. The morphogenetic system is a set of interdependent processes that are responsible for changes to landscape morphology, which cause the flow or movement of matter (Tricart, 1972). The intensity of such flows and the mass of the materials that are transported are decisive factors in the functioning of an ecosystem. Morphogenesis has radiation energy and gravitational attraction as sources of energy that feed the fluxes of matter, resulting in disequilibrium and changes to landscape morphology. Thus, morphogenetic processes tend to give rise to topographic instability, change of land morphology and also limit or suppress the development of plant and animal communities.

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A system in morphogenesis is characterised by an ecosystem which is less evolved, less productive, with reduced biomass production and which is thought to be more susceptible to the erosion processes (Tricart, 1972). Apart from the weakness of systems in morphogenesis, morphogenetic processes are fast, leading to rapid soil loss. A morphogenetic system usually includes processes of ablation, transport and accumulation of materials (Tricart, 1965). Ablation involves the prior occurrence of physical, chemical and biological weathering, which strongly depends on climatic conditions. Transport involves water, wind and gravity, and parameters such as speed and distance essentially obey to the laws of physics. Accumulation occurs when the transport agents lose their energy, which depends mostly on the topographical conditions of the site. Therefore, morphogenesis is related to the agents of erosion. Landscape degradation caused by erosion can occur through so-called natural processes (normal or geological erosion) and anthropic processes (accelerated erosion). Geological erosion is a natural process that, in the majority of cases, does not represent a risk. The risk arises when natural erosion processes are accelerated. While the natural dynamic balance of the landscape has not changed, erosion processes are carried out at such a rate that the redistribution of the particulated material is compensated for by soil genesis. The rupture of equilibrium corresponds to the change from a slow evolution of the landscape to an accelerated evolution. An important aspect of landscape degradation is accelerated erosion. The effect of accelerated erosion is expressed by the loss of soil constituents, particularly inorganic and organic colloids and nutrients. Consequently, there is a loss of essential nutrients for plants and a reduction in the thickness of the soil, resulting in barren areas (Brady & Weil, 2008). Accelerated erosion occurs when people disturb the soil or the natural vegetation by grazing, livestock, cutting forests for agricultural use, ploughing hillsides, or tearing up land for facilities construction (roads and buildings) without taking into account the natural function (matter and energy fluxes) of the landscape. As a matter of fact, with the emergence of mankind, a disturbing element disturbed the natural equilibrium (Cabral, 1993). The cultural landscape reflects the interactions between people and their natural landscapes, forming a complex mosaic structure including agriculture, pasture and forest (Farina, 1998). The landscape undergoes an evolution where its resources are exploited by humans. Mankind always has had an impact on landscape evolution (Hart, 1986), and with the industrial revolution and evolution of new technologies, the impact has increased and therefore resulted in natural resources becoming increasingly scarce. Anthropic degradation primarily affects vegetation and soils (Tricart, 1972). This anthropic landscape degradation causes a disequilibrium that arises from incorrect land use practices. These practices usually accelerate soil erosion, causing soil losses. Other landscape components can accelerate soil loss, like characteristics of the soil, rainfall characteristics, slope degree and vegetation cover. The improper use of landscapes by humans is present in several types of land uses: agriculture, pastoralism, forestation and urban expansion.

Agriculture Human land use has degraded five billion hectares of the Earth’s vegetated land during the second half of the 20th century, which is about 43% of the Earth’s total land surface

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(Brady & Weil, 2008). The removal of natural vegetation and subsequent tillage of the soil for crop production has abruptly changed soil properties. Agricultural systems have been evolving throughout history leading to land productivity maximisation without any, or less, concern for the landscape and its natural equilibrium. The replacement of natural vegetation with non-native vegetation is one of the first factors leading to disequilibrium, and through the fact that biomass is also produced, soil nutrients decreased and biogechemical cycles are disturbed. Since the time that humans started to use agriculture, the average sediment load of the world’s rivers has been estimated to have more than doubled (Sawkins et al., 1978). Soil erosion becomes more significant when the soil is completely bare. Agricultural lands are also subject to these dangers until the plants have grown large enough in order to fulfil one of their crucial functions – soil protection. Conventional agriculture practices have encouraged extensive soil tillage, which give rise to bare and unprotected soils that lead to soil erosion. Soil is commonly washed out, or blown away faster than new soil can form by weathering, pedogenesis or deposition. Consequently, the soil depth suitable for plant roots is often reduced (Brady & Weil, 2008). Recently, conservation tillage systems have been used that leave significant amounts of organic residues on the soil surface after harvest, which protects soil from accelerated erosion and reduces nutrient losses. Therefore, adapting agricultural techniques and practices to the environment is part of the sustainable use of that landscape. This requires good knowledge of soil characteristics and environmental conditions and in what measure these change and evolve in response to human intervention.

Pastoralism/Grazing Pastoralists are engaged in active efforts to reduce the probability of unavoidable hazards by managing temporal and spatial diversity in grazing opportunities and livestock capabilities (Roe et al., 1998). However, this can contribute to landscape degradation if it is done using intensive practices. One example of these practices is a number of excessive livestock per unit of area, which will lead to soil compaction and consequently soil erosion. The decrease in vegetation and soil compaction will reduce water infiltration, increasing runoff and contributing to soil loss by hydric erosion. Forestation Natural vegetation has been replaced over many decades with other productive species. In the forest, replacements have been made by introducing species with faster growth, greater economic benefits and fewer benefits in terms of the ecosystem’s equilibrium. The major problem with these species is that they are flammable and normally planted in large monospecific areas that facilitate wildfire (Loepfe et al., 2010). Consequently, this type of land use increases erosion risk by being a continuously flammable area, which might lead to the absence of vegetation and soil loss by erosion. The variability of natural vegetation that is expected to occur in the landscape, which is given by the Natural Potential Vegetation model (Capelo et al., 2007), should be a strength and an opportunity for the economy. Woodlands are fundamental for water and soil conservation, and contribute to biodiversity enrichment. Consequently, the economic value of woodlands has to be promoted alongside environmental protection.

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Riverbanks are areas susceptible to water erosion, depending on the water flow velocity, the lithological materials and, particularly, the absence of natural vegetation. The lack of riparian woodlands leads to accelerated erosion on those areas, since vegetation is a flow velocity reducer. Unfortunately, it is a common practice in some municipalities to “clean” riverbanks by eradicating all vegetation, which contributes to landscape degradation.

Urban Expansion Since antiquity, most urban areas have been located in the proximity of soils with a high potential for agriculture. However, recent urban expansion processes have strongly threatened the existence and quality of those soils (Magalhães, 2001; Pipkin et al., 2005). In urbanising areas, the effect on soils is almost akin to that of the ancient glaciers, where the clock of soil formation was set back to zero (Brady & Weil, 2008). Thus, urban expansion must be planned in order to not endanger this highly valued natural resource. Despite this, soils with high value for biomass production are scarce. Urban expansion should be developed in areas with fewer ecological constrains, such as areas in which soils are of poorer quality.

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3.3. Pedogenesis Pedogenesis represents the equilibrium state of the landscape system. In this state, the system presents conditions providing for biomass production, supporting life, and for soil and water conservation. This system plays an important role in the cycling of chemical elements and in the evolution and accumulation of organic matter in soil, contributing to carbon sequestration. Soil is a natural body consisting of layers of mineral and organic constituents of variable thickness, which differ from their parent materials in their morphological, physical, chemical, and mineralogical properties and their biological characteristics (Birkeland, 1999). Parent material, climate, organisms (biota), topography and time are the environmental factors of soil genesis which contribute to the definition of the soil system (Birkeland, 1999; Brady & Weil, 2008). The parent material is the material from which soil is formed, including both weathered and unweathered materials (Birkeland, 1999). Consequently, the nature of the parent material influences soil characteristics, such as texture, type of clay minerals, soil pH, permeability, and plant nutrients, which influence the type of natural vegetation which can grow in the soil (Brady & Weil, 2008). The natural vegetation is also responsible for the pedogenetic processes. The principal climatic variables influencing soil formation are precipitation and temperature. The climate is a pedogenetic factor, which determines the nature and intensity of weathering that occurs over a large geographic area (Brady & Weil, 2008). Organisms, mainly native vegetation, animals (especially earthworms and termites), fungi and bacteria, and increasingly human beings, are also responsible for the development of soils. They have an influence on organic matter accumulation, biochemical weathering, profile mixing, nutrient cycling and aggregate stability (Brady & Weil, 2008). Topography is described in terms of differences in elevation, shape and landscape position (Brady & Weil, 2008). On steep slopes, rainfall moves rapidly downhill and the

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bedrock is usually less weathered. Therefore, slopes tend to have rather shallow, poorly developed soil profiles. In contrast, in the lowest landscapes, weathering can be more intense and soil profile development is more advanced and thick. However, water may saturate the soil to such a degree that drainage and aeration are restricted. The topography of the landscape often influences the type of vegetation which will in turn influence soil characteristics. Topography also affects the absorbance of solar energy. Consequently, warmer slopes are commonly lower in moisture, which can influence the soil organic matter. The interaction of environmental variables establishes soil forming processes whose actions on parent materials manifest themselves as characteristic soil morphologies which may alter the nature of ongoing processes (Chadwick & Graham, 2000). Thus, the interdependency of factors and processes that lead to soil formation and evolution is a rule (Brady & Weil, 2008). Pedogenetic processes take time to show their effects. The time factor is the elapsed time since the deposition or the exposure of materials on the Earth’s surface which influence the weathering rate, or formation of the slope to which the soil relates (Birkeland, 1999). Soilforming processes are very slow. Soil genesis has a thickness formation rate of 0.1 mm/year to 1 mm/year (Zachar, 1982), depending on other factors influencing soil formation, which means soil should be considered as a non-renewable resource at the human scale (Magalhães, 2001). Soils, landscapes and superficial materials/rocks together comprise three-dimensional systems that co-evolve through the interaction of physical and chemical weathering, erosion and deposition (Wysocki et al., 2000). Soil forming processes and the described factors which influence them provide a framework for predicting the nature of soil bodies likely to be found on a particular site (Brady & Weil, 2008). Soil organisation and its functioning allows us to consider soil as an ecological system to which the properties of systems are applicable, especially those related to living organisms where energy flux and matter cycling occur (Brady & Weil, 2008; Gobat et al., 2004; Odum, 1971). In planning landscapes, minimum disturbance of the natural soil-forming processes should be a goal (Pena & Abreu, 2005). Different land uses will have different influences on soil properties (Marzaioli et al., 2010); consequently, they should be planned correctly, according to the functioning of landscape sub-systems. Thus, agriculture and pastoralism can be understood as land uses which can also contribute to soil evolution. However, these soil uses must be undertaken using sustainable practices (Zuazo et al., 2009) in order to not compromise the equilibrium of the landscape.

4. LANDSCAPE GEOMORPHOLOGIC DYNAMICS APPLICATION OF ASSESSMENT CASE STUDIES 4.1. Methodology The Landscape Geomorphologic Dynamics assessment methodology is accomplished through the gathering and interpretation of field data collection (field survey), which is complemented with published documents and cartography (previously known factors).

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This methodology allows for mapping homogeneous areas for each class (Morphogenesis, Pedogenesis, Intergrade to Morphogenesis and Intergrade to Pedogenesis) in cartographic data integration with the use of a Geographic Information System. As previously known factors, the existent cartography and documentation are used and comprise the following maps and the respective published information: geology-lithology, topography, slopes, soils, land morphology and orthophoto maps. The observed factors in field survey are properly analysed, interpreted and mapped in a topographic base. These factors include soil and geological erosion, rock weathering (when observable and the respective depth), rocky outcrops, soil characteristics and relative thickness, when observable, soil use, cultural practices and vegetation cover (type and density). Through this methodology, areas are classified as follows: Morphogenesis, Pedogenesis, Intergrade to Pedogenesis and Intergrade to Morphogenesis (Figure 3).

Figure 3. Landscape Geomorphologic Dynamics assessment methodology.

4.2. Case Studies Landscape Geomorphologic Dynamics assessment was applied to the Sintra and Almada municipalities located in the Lisbon Metropolitan Area (Figure 4). The Sintra municipality comprises 317 km² and has three general types of landscape: a rural landscape, in the north; an urban landscape, in the south; and a hill landscape represented by Sintra hill and located in the west. The diversity of landscapes in this municipality is very helpful for the study and application of LGD assessment. The Almada municipality is smaller (70.2 km²) than the Sintra municipality, but presents a higher urban pressure with 2366 inhabitants/km2, while Sintra municipality has 1437 inhabitants/km2.

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The simplified geology-lithology map of the municipalities is shown in Figure 5. Due to the geological lithological diversity and the susceptibility of the analysed landscapes in both municipalities, the areas classified as in the Intergrade situation were subdivided into Intergrade I and Intergrade II. The Intergrade I geomorphic dynamic means that the landscape dynamic is closest to the class specified in the classification, while the Intergrade II geomorphic dynamic refers to a class in which the characteristics are far away from the same class. Intergrade to Morphogenesis I are areas in the Intergrade situation where intense degradation is observed, whereas Intergrade to Morphogenesis II areas correspond to those in the Intergrade situation but presenting some stabilisation indicators (Table 1). Thus, from the point of view of geomorphological dynamics, the study areas were classified into six different classes: Morphogenesis, Intergrade to Morphogenesis I, Intergrade to Morphogenesis II, Intergrade to Pedogenesis II, Intergrade to Pedogenesis I and Pedogenesis (Table 1 and Figure 6). Table 1. Description of the six Landscape Geomorphologic Dynamics (LGD) classes LGD classes Morphogenesis Intergrade to Morphogenesis I Intergrade to Morphogenesis II Intergrade to Pedogenesis II Intergrade to Pedogenesis I Pedogenesis



Stability

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Figure 4. Study area locations.

Description Degraded areas due to accelerated and geological erosion Areas in Intergrade with intense degradation Areas in Intergrade with some stabilisation indicators Areas in Intergrade with some degradation Areas in Intergrade with some stabilisation Stable areas with biomass production

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The percentage of each LGD class in the Sintra and Almada municipalities is shown in Table 2. The Sintra municipality presented a higher percentage of areas classified as stable classes than Almada, which was due to important human pressure observed in this region. In fact, Almada is a small municipality with large urban sprawl and a history of inadequate landscape management measures, and the built-up areas represent approximately 55% of the total area. Table 2. Description and quantification (% of the total area) of the six Landscape Geomorphologic Dynamics (LGD) classes for Sintra and Almada municipalities LGD classes

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Morphogenesis Intergrade to Morphogenesis I Intergrade to Morphogenesis II Intergrade to Pedogenesis II Intergrade to Pedogenesis I Pedogenesis Built-up areas

Figure 5. (Continued).

Sintra Municipality 5.70 7.61 12.35 19.03 23.50 14.24 17.57

Almada Municipality 14.33 8.18 7.41 1.80 7.17 6.54 54.58

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Figure 5. Simplified geology-lithology map of Sintra and Almada municipalities (adapted from Magalhães et al., 2005; 2006).

Figure 6. (Continued).

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Figure 6. Landscape Geomorphic Dynamics assessment of Sintra (top) and Almada (bottom) municipalities.

(i). Morphogenesis Areas Morphogenesis classes comprise unstable degraded landscape areas, as a result of accelerated or geologic erosion processes. In the Sintra municipality, unstable areas are represented by limestone quarries (Figure 7a) and areas where mass wasting by landslides and rill or gully erosion take place. Limestone quarries are very common in the north of the Sintra municipality, and waste materials from this industrial activity are deposited in heaps that, in most situations, can obstruct the streams and modify the land’s natural morphology. Mass wasting appears especially in steep slopes, with a lack of vegetation cover and a clastic sedimentary lithological substratum (Figure 7b). Fire also contributes to landscape instability because bared soils are strongly subject to soil erosion in Mediterranean climatic conditions, with local, heavy and intense rainfall. Areas in morphogenesis were also found on the coastlines, both on cliffs and beaches due to wind and wave erosion. In a great number of cases, anthropic actions increased the rate of these erosive processes, through the high pressure of building and infrastructure construction. This class covers 5.7% of the total municipality area, corresponding to the lowest proportion of the total land area. In the Almada municipality, morphogenesis areas comprised 14% of the total municipality area. They were located mainly on the north and west sides of the municipality, along the coastline, in the contiguous areas of streams (flat surfaces of the valley) and on some steeper slopes. In the north, the morphogenetic processes occurring on the cliffy coast depend on several factors as lithological characteristics, slopes, climatic conditions and human actions.

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Sedimentary rock formations are part of a monocline structure organised in strata with different mineral compositions, hardness, permeability and plasticity. Those strata will have different behaviours in response to external geodynamic processes. Differential erosion processes take place as a consequence of the alternation between strata composed of fractured hard rocks (calcarenite or limestone) and soft rocks such as clays and marls. In addition, the built-up areas near the cliffs increase pressure, which leads to an increase in erosion by rock falls, landslides and mudflows. Along the northern and western coast, the dune systems were subject to degradation due to edification pressure (Figure 8a), industrial establishments and incorrect (non-native and invasive) vegetation cover (e.g. Carpobrotus edulis (L.) N. E. Br. in E. Phillips).

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(a)

(b) Figure 7. Morphogenesis areas in the Sintra municipality: (a) limestone quarry; (b) mass wasting (gully erosion) in the hill slope in the Sintra municipality.

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Soil impermeabilisation by edification was constant in several areas of the Almada municipality, and bank erosion along some streams was also observed (Figure 8b). Steeper slopes on clastic Miocene and Pliocene rocks, which present high susceptibility to erosion processes, showed deep mass movements in areas without vegetation cover.

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(a)

(b) Figure 8. Morphogenesis areas in the Almada municipality: (a) building pressure along coastal area; (b) bank erosion along the water line with deep mass wasting and headwater erosion.

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(ii). Pedogenesis Areas Pedogenesis areas are those where soil genesis and conservation are promoted, and favourable conditions for biomass production as well as minimal erosion processes occur. In the Sintra municipality, those areas are located in flattened wide valleys or in depressed areas (Figure 9a), footslopes, summits (gently waved) (Figure 9b), slight slopes with good vegetation cover (natural woods), correct landscape compartmentation (olive tree hedges) or with sustainable agricultural use. The areas with Pedogenesis processes correspond to 14% of the total area of the Sintra municipality.

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(a)

(b) Figure 9. Pedogenesis areas in the Sintra municipality: (a) flattened wide valley; (b) Gently waved summit in a pedogenesis dynamic.

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In the Almada municipality, the total areas in pedogenesis processes were smaller than in the Sintra municipality and corresponded to 7% of the total area. Among them were agricultural fields with correct compartmentation, pinewoods that fixed coastal dunes and flattened summit areas where good agricultural practices (Figure 10) were followed.

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(a)

(b) Figure 10. Pedogenesis areas in the Almada municipality: (a) agricultural land; (b) agricultural land with a fossil cliff behind it.

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(iii). Intergrade to Morphogenesis Areas

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Intergrade to Morphogenesis I Areas classified as Intergrade to Morphogenesis I show intense degradation and represent in the Sintra municipality approximately 8% of the total area (Table 2). However, the rate of this degradation is less than that observed in areas classified as in morphogenesis. In the Sintra municipality, the factor that mainly contributes to this geomorphic dynamic is the lack of vegetation cover in sensitive areas where vegetation would be crucial to improve pedogenesis (Figure 11). Such sensitive areas have been delimited to include soft rocks where the soils are still incipient (Leptosols, Regosols) and sedimentary rocks with alternating strata of argillaceous or marly rocks, as well as limestones and sandstones. Those strata present direction and attitude concordant with the direction of the slope, which can be responsible for disrupting the equilibrium of these areas. Also, steep slope areas where agriculture activity has been abandoned but have not been converted to woodland, and areas where livestock cause soil compaction with the consequent increase of erosion processes (rill or gully erosion) were included in the Intergrade to Morphogenesis I class. Incorrect agricultural practices, conjugated with the soil type, are the main factors that contribute to mass wasting. The spread of urban and/or industrial wastes near or even in seasonal streams is another factor of instability, as it disturbs the correct hydrological function of the hydrological basin, causing instability upstream and downstream.

(a) Figure 11. (Continued).

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(b) Figure 11. Intergrade to Morphogenesis I areas in the Sintra municipality. Mass movement in steep slopes with insufficient vegetation cover.

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In the Almada municipality, the percentage of the areas in Intergrade to Morphogenesis I was similar to that in the Sintra municipality (Table 2). This geomorphic dynamic occurred on some stream banks and on steeper slopes where inadequate practices were taking place. Headwater streams are mostly impervious areas as a result of human landscape intervention (Figure 12a). This will affect the normal function of the watershed, increasing runoff and flood risk downstream (Figure 12b).

(a) Figure 12 (a). Impervious areas in the stream watershed from the Almada municipality: headwater stream.

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(b) Figure 12 (b). Impervious areas in the stream watershed from the Almada municipality: flat surface valley areas.

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Intergrade to Morphogenesis II The Intergrade for Morphogenesis II areas already show some landscape stabilisation indicators such as vegetation cover and/or sustainable agricultural practices. However, it has been noted in some areas, soil erosion, and soil compaction together with intense urban pressure (edification and waste disposal). These areas correspond to 12% of the total area in the Sintra municipality. The south slope of Sintra hill was classified as Intergrade to Morphogenesis II because, in some places, outcrops as a result of soil erosion or shallow mass movements due to decreased vegetation (wildfire events) were observed on a slope with the driest conditions (Figure 13a).

(a) Figure 13(a). Intergrade to Morphogenesis II areas: the south slope of Sintra hill.

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(b)

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Figure 13 (b). Intergrade to Morphogenesis II areas: vegetation covering dunes on the Almada coastline with the fossil cliff on the right.

In the Almada municipality, the Intergrade to Morphogenesis II areas comprised about 7% of the total area, showing different erosion process intensities. Those areas were limited by vegetation patches where plants were growing. Some dune areas showing a few erosion processes were also included in this classification, although these areas were protected with vegetation. However, this vegetation was comprised of infesting species like Acacia sp., which are not adequate for dune systems located in this geographic area (Figure 13b). This class also included the areas where urban pressure began, showing a tendency to edification spread and soil impermeabilisation.

(iv). Intergrade to Pedogenesis Areas Both Intergrade to Pedogenesis I and II areas are evolving towards Pedogenesis. However, Intergrade to Pedogenesis I areas are closer to stabilisation than Intergrade to Pedogenesis II areas. If Intergrade to Pedogenesis II areas present some landscape degradation processes, the geomorphic dynamic could easily turn into Intergrade to Morphogenesis II. In the Sintra municipality, the Intergrade to Pedogenesis areas represented 40% of the total area, whereas for Almada, this percentage was relatively small (9% of the total).

Intergrade to Pedogenesis II In the Sintra municipality, the Intergrade to Pedogenesis II areas included old quarries that already presented vegetation showing, consequently, dynamics that tended towards landscape stabilisation. This classification also included areas with soil showing low nutritional value, but where biomass production has been implemented. Urban agricultural

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areas near edification that could be at risk due to urban pressure proximity were also classified as Intergrade to Pedogenesis II, as well as the steep slope areas with dense vegetation cover (Figure 14a). In the Almada municipality, the Intergrade to Pedogenesis II dynamics took place in areas where soil erosion was observed in spite of vegetation cover, meaning that its removal led to morphogenesis (Figure 14b). Slope factor determined in the Intergrade to Pedogenesis II areas a tendency for accelerated/geological erosion, especially if combined with clastic and/or soft sedimentary lithologies. Consequently, these areas should be monitored in order to maintain and improve the pedogenesis processes.

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(a)

(b) Figure 14. Intergrade to Pedogenesis II areas: (a) North slope of Sintra hill; (b) slope in Almada municipality with slight erosion and sparse vegetation.

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Intergrade to Pedogenesis I The Intergrade to Pedogenesis I areas in the Sintra and Almada municipalities corresponded to rural areas with sustainable agriculture and soil conservation. Gently waved summits with vegetation cover and stream banks with more-or-less developed riparian vegetation were also included in this geomorphologic class (Figure 15).

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(a)

(b) Figure 15. Intergrade to Pedogenesis I areas. Sustainable agricultural practices in (a) the Sintra municipality and (b) the Almada municipality.

Selma Beatriz Pena and Maria Manuela Abreu

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Figure 16. LGD Management Plan–Priority classes for the Sintra (top) and Almada (bottom) municipalities.

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5. LANDSCAPE GEOMORPHOLOGIC DYNAMICS ASSESSMENT AND LAND MANAGEMENT Landscape Geomorphologic Dynamics assessment is a landscape diagnosis framework that informs stake holders about the evolutionary stage of the landscape. In articulation with ecological networks (Cook, 2002; Gurrutxaga et al., 2010; Hepcan et al., 2009; Jongman, 1995; Jongman et al., 2004; Magalhães et al., 2007; Zhang & Wang, 2006), this knowledge provides a definition of management measures for those areas, as well as prioritisation towards field implementation. A landscape is a dynamic and an open system where a set of interdependent processes interact to accomplish a natural (dynamic) equilibrium. This concept must be taken into account for landscape management. Therefore, it is necessary to be aware that every action or modification of the landscape will generate a negative or positive reaction by the landscape (Huggett, 2003; Pena et al., 2010; Tricart, 1994). The basic principles of landscape planning are the following (Telles, 2001):

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1) Continuum naturale - continuous system of natural events that allow the functioning of ecosystems and the permanence of genetic potential (biodiversity); 2) Continuum culturale - continuous system of built-up spaces and urban voids; 3) Genius loci – places beyond the physical place, which comprises symbolic values and history; 4) Versatility (multifunction) of the landscape area – considering the protection, production and recreation functions in order to achieve an intensity of biological processes through sustainability, resilience and biodiversity; 5) Capacity for self-regulation, self-regeneration and self-purification of natural resources – leading to the maintenance, continuity and stability of the landscape. The Morphogenesis/Pedogenesis rate is therefore crucial in landscape planning and management because it allows for the assessment of landscape stability/instability. With this knowledge, it is possible to establish priority actions to the achievement of the dynamic equilibrium of the landscape. In Table 3, the relationship between the Landscape Geomorphologic Dynamics (LGD), the stability/instability of the landscape and the priority actions for each LGD class are given. The priority actions in the Management Plan comprise land use conservation, recovery or conversion (Figure 16). In the case studies, the priority classes are mapped (Figure 16) based on the LGD assessment (morphogenesis/pedogenesis rate) mapped in Figure 5. The Ecological Network allows the coexistence between humans and landscape in a sustainable manner (Magalhães, 2001). Consequently, ecological systems need to be protected for the conservation and sustainability of natural resources: soil, water and vegetation. The Ecological Network comprises the areas that support environmentally sensitive ecological systems which must be protected. These systems are mainly the wet systems, areas with substantial soil erosion risk, maximum infiltration areas, soils with high ecological value and natural and semi-natural vegetation (Magalhães et al., 2007). The Ecological Network for the studied municipalities was designed in the CEAP R&D Unit (Magalhães et al., 2003; 2005; 2008).

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Figure 17. First level of intervention in the LGD management plan obtained from the Ecological Network and priority actions for the Sintra (top) and Almada (bottom) municipalities.

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Table 3. Landscape Geomorphologic Dynamics (LGD) Assessment and Management Plan

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LGD Assessment Morphogenesis/Pedogenesis Landscape Rate Stability/instability Morphogenesis Instability Intergrade to Morphogenesis I

Tendency for instability

Intergrade to Morphogenesis II Intergrade to Pedogenesis II

Tendency for instability Tendency for stability

Intergrade to Pedogenesis I

Tendency for stability

Pedogenesis

Stability

LGD Management Plan Priority Priority classes Action Land use Very urgent conversion Land use Very urgent recovery or conversion Land use Urgent recovery Land use Urgent/Medium recovery Land use Medium recovery or conservation Land use Minimum conservation

As the Ecological Network is essential for an adequate balance of the landscape, the previously defined priority actions should be applied in the Ecological Network system, which represents the first level of intervention (Figure 17). After the implementation of the first intervention level, the municipality should implement the second level of the LGD management plan, which is applied to the remaining areas not included in the Ecological Network. The general stability measures for land use recovery and conversion are presented in Table 4. The implementation of these measures will promote stability in degraded areas, and the landscape system will readapt towards stability.

CONCLUSION A landscape is a complex open system comprised of several ecological and cultural systems standing in interaction and in permanent evolution. Humans, as a component of the landscape, play an important role in its evolution. Despite being normally associated with a bad influence on the environment, humans can also have a positive effect, especially in the decision-making processes with the approval of coherent Landscape Management Plans. Landscape Geomorphic Dynamics assessment gathers a set of information on landscape factors which allow for diagnosing measures of landscape stability. This analysis designs a framework to promote landscape dynamic equilibrium. Landscape Geomorphic Dynamics assessment applied to the Ecological Network can lead to the accomplishment of priority intervention actions where management measures of recovery, conversion and redevelopment of land uses are proposed. The goal is sustainable land use in order to promote pedogenesis dynamics and to attain landscape dynamic stability.

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Table 4. General stability measure (land use) for each typological instability situation Instability areas

Stability measures – land uses

Mass wasting, creeping, mudflows, landslides, rill and gully erosion

Soil protection with natural vegetation. Sensitive zones: summits and steeper slopes

Riverbanks, stream flow

Riparian gallery

Incorrect agricultural practices: crops planted along maximum gradient lines

Sustainable agricultural practices: crops planted along contour lines

Introduce temporary grassland in crop rotations

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Incorrect agricultural practices: abandoned, bare soils. Compaction by the use of heavy machinery or livestock trampling. Permanent grassland Deforestation in bare soils

Stability measures – land uses

Combination strips of crops and shrubs

Aeolian erosion in agriculture fields

Edges in the border of fields

Aeolian erosion in dune systems

Specific dune vegetation

Human pressure on clifftops

Building forbidden. Vegetation protection.

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Landscape Geomorphic Dynamics assessment is an important tool for decision-makers on landscape evolution, and for determining what priority actions must be taken, for specific landscape time planning.

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REFERENCES Abreu, M.M., Magalhães, M.R., Cunha, N.S., Campo, S.L. & Silva, P.G. (2003). The landscape geomorphic dynamic as a contribution for the Local Ecological Structure– Loures a Municipality of Lisbon Metropolitan area (Portugal). Proceedings of the 4th European Congress on Regional Geoscientific Cartography and Information Systems. Geoscientific Information for Spacial Planning. Vol. I: 199-201. Bologna, Italy. Abreu, M.M., Magalhães, M.M.R., Pena, S.B. & Cunha, N.S. (2007). Aplicação do balanço morfogénese/pedogénese à Estrutura Ecológica da Bacia da Ribeira da Jarda (concelho de Sintra): importância no Ordenamento do Território. Dinâmicas geomorfológicas. Metodologias. Aplicação. Associação Portuguesa de Geomorfólogos Volume V, 249262, APGeom, Lisboa. Amaral, R. & Ross, J.L.S. (2009). As Unidades Ecodinâmicas na análise da fragilidade ambiental do Parque Estadual do Morro do Diabo e Entorno, Teodoro Sampaio/SP. GEOUSP – Espaço e Tempo, 26, 59-78. Barnes, T.G. (2000). Landscape Ecology and Ecosystems Management. FOR-76, 1-8. http://www.ca.uky.edu/forestryextension/Publications/FOR_FORFS/for76.pdf (access November 2010). Birkeland, P.W. (1999). Soils and Geomorphology. (3rd Edition). New York: Oxford University Press. Brady, N.C. & Weil, R.R. (2008). The Nature and Properties of Soils. (14th edition). New Jersey, USA: Pearson Prentice Hall. Bull, W.B. (1991). Geomorphic responses to climate change. New York: Oxford University Press. Cabral, F.C. (1993). Fundamentos de Arquitectura Paisagista. Lisboa: ICN. Capelo, J., Mesquita, S., Costa, J.C.C., Ribeiro, S., Arsénio, P., Neto, C., Monteiro-Henriques S.T., Aguiar, C., Honrado, J., Espírito-Santo, D. & Lousã, M. (2007). A methodological approach to potential vegetation modeling using GIS techniques and phytosociological expert-knowledge: application to mainland Portugal. Phytocoenologia, 37, 3-4, 399-415. Chadwick, O.A. & Graham, R.C. (2000). Pedogenic Processes. In M.E. Summer (ed.). Handbook of Soil Science, E41-E75, Boca Raton, London: CRC Press. Christofoletti, A. (1980). Geomorfologia. São Paulo: Adgard Blücher. Cloquell-Ballester, V., Monterde-Díaz, R., Cloquell-Ballester, V. & Torres-Sibille, A.C. (2008). Environmental education for small- and medium-sized enterprises: methodology and e-learning experience in the Valencian region. Journal of Environmental Management, 87, 507–520. Cook, E.A. (2002). Landscape structure indices for assessing Urban Ecological Networks. Landscape and Urban Planning, 58, 269-280. Council of Europe (2000). The European Landscape Convention. http://www.coe.int/t/e/ Cultural_Co-operation/environment/Landscape/. (access September 2010).

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Farina, A. (1998). Principles and methods in landscape ecology. London: Chapman&Hall. Gobat, J., Aragno, M. & Matthey, W. (2004). The living soil. Fundamentals of soil science and soil biology. USA: Science publishers, Inc. Gurrutxaga, M., Lozano, P. & Barrio, G. (2010). GIS-based approach for incorporating the connectivity of Ecological Networks into a Regional Planning. Journal for Nature Conservation, 18, 318-326. Hart, M.G. (1986). Geomorphology, pure and applied. London: George Allen & Unwin. Hepcan, S., Hepcan, C.C., Bouwma, I.M., Jongman, R.H.G. & Özkan, M.B. (2009). Ecological Network as a new approach for nature conservation in Turkey: a case study of Izmir Province. Landscape and Urban Planning, 90, 143-154. Huggett, R.J. (2003). Fundamentals of Geomorphology. Routledge Fundamentals of Physcal Geography. Jongman, R.H.G. (1995). Nature Conservation Planning in Europe: developing Ecological Networks. Landscape and Urban Planning, 32, 169-183. Jongman, R.H.G., Külvik, M. & Kristiansen, I. (2004). European Ecological Networks and Greenways. Landscape and Urban Planning, 68, 305-319. Jorgensen, S.E. & Svirezhev, Y.M. (2004). Towards a Thermodynamic Theory for Ecological Systems. Oxford: Elsevier. Loepfe, L., Martinez-Vilalta, J., Oliveres, J., Piñol, J. & Lloret, F. (2010). Feedbacks between fuel reduction and landscape homogenisation determine fire regimes in three Mediterranean areas. Forest Ecology and Management, 259, 2366–2374. Magalhães, M.R. (2001). A arquitectura Paisagista morfologia e complexidade. Lisboa: Editorial Estampa. Magalhães, M.R., Abreu, M.M., Cortez, N., Lousã, M., Cunha, N., Campo, S.L., Silva, P.G., Raposo, C., Espírito-Santo, D., Costa, J.C., Rego, T. & Mesquita, S. (2003). Plano Verde de Loures–Final Report. Magalhães, M.R., Abreu, M.M., Marques, M., Lousã, M., Mata, D., Cunha, N., Campo, S.L., Pena, S.B., Costa, J.C., Mesquita, S. & Arsénio, P. (2005). Plano Verde do Concelho de Sintra (1 Fase)–Final Report. Magalhães, M.R., Abreu, M.M., Cortez, N., Lousã, M., Mata, D., Cunha, N., Campo, S.L., Pena, S.B., Ferro, I. & Saavedra, A. (2006). Estruturas da Paisagem do Concelho de Almada–Ecológica, Cultural e Ciclável–Contribuições para o Ordenamento Municipal– Final Report. Magalhães, M.R., Abreu, M.M., Lousã, M. & Cortez, N. (2007). Estrutura Ecológica da Paisagem, Conceitos e Delimitação – escalas regional e municipal. Lisboa: Isapress. Magalhães, M.R., Abreu, M.M., Marques, M., Lousã, M., Mata, D., Cunha, N., Campo, S.L., Pena, S.B., Saavedra, A., Costa, J.C., Mesquita, S. & Arsénio, P. (2008). Plano Verde do Concelho de Sintra (2 Fase) –Final Report. Marzaioli, R., D’Ascoli, R., De Pascale, R.A. & Rutigliano, F.A. (2010). Soil quality in a Mediterranean area of Southern Italy as related to different land use types. Applied Soil Ecology, 44, 205–212. Odum, E.P. (1971). Fundamentals of Ecology. Philadelphia, PA (USA): Saunders College Publishing. Pena, S.B. & Abreu, M.M. (2005). A Importância dos Solos no Ordenamento do Território. Caso dos Barros desenvolvidos no Complexo Vulcânico de Lisboa. IV Seminário Recursos Geológicos, Ambiente e Território. DVD (E-42-E-46), Vila Real, Portugal.

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Pena, S.B., Abreu, M.M., Teles, R. & Espírito-Santo, M.D. (2010). A Methodology for creating greenways through multidisciplinary sustainable landscape planning. Journal of Environmental Management, 91, 970–983. Pipkin, B., Trent, D.D. & Hazlett, R. (2005). Geology and the Environment. 4th edition. USA: Thomson, Brooks/Cole. Roe, E., Huntsinger, L. & Labnow, K. (1998) High reliability pastoralism. Journal of Arid Environments, 39, 39-55. Sawkins, F.J., Chase, C.G., Darby, D.G. & Rapp Jr, G. (1978). The Evolving Earth. A text in physical geology. New York: Macmillan. Small, R.J. (1970). The study of Landforms. Cambridge: University press. Telles, G.R. (2001). Plano Verde, Estrutura Ecológica e Componentes Ambientais. Lisboa e Urbanismo, 16, 44. Tricart, J. (1962). L’Epiderme de la Terre. Esquisse d’une géomorphologie appliquée. Paris: Masson. Tricart, J. (1965). Morphogènese et pédogènése, géomorphologie et pédologie. Science du Sol, 1, 69-85. Tricart, J. (1972). La Terre planète vivante. Paris: Presses Universitaires de France. Tricart, J. (1994). Écogéographie dês Espaces Ruraux. Paris: Nathan. Wysocki, D.A., Schoeneberger, P.J. & LaGarry, H.E. (2000). Geomorphology of Soil Landscapes. In M.E. Summer (ed.) Handbook of Soil Science, E5-E39, Boca Raton, London: CRC Press. Zachar, D. (1982). Soil erosion. Amsterdam: Elsevier Scientific Publishing Company. Zhang, L. & Wang, H. (2006). Planning on Ecological Network of Xiamen Island (China) using landscape metrics and network analysis. Landscape and Urban Planning, 78, 449456. Zuazo, V.H., Pleguezuelo, C.R.R. & Pandero, L.A. (2009). Soil Conservation Measures in Rainfed Olive Orchards in South-Eastern Spain: Impacts of Plant Strips on Soil Water Dynamics. Pedosphere, 19(4), 453–464.

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In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 7

RESTORATION AND THE SUSTAINABLE USE OF COMPLEX LANDSCAPES: AN INTEGRATIVE CONCEPTUAL MODEL Roberto Lindig-Cisneros1, Ian MacGregor-Fors2, Rubén Ortega-Álvarez1 and Arnulfo Blanco-García3 1

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Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Campus Morelia, Morelia, Michoacán, Mexico 2 Instituto de Ecología, El Haya, Xalapa, Veracruz, Mexico 3 Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Michoacán, México

1. INTRODUCTION Conceptual models are common in restoration ecology and some, like Bradshaw's model (1984), have been greatly influential to the research agenda. Being developed from a scientific perspective, most models address issues related to the ecological aspects of restoration processes, such as the relationship between structure and function (Bradshaw, 1984) or the relationship between the conditions of restored sites and their surroundings (Palmer et al., 1997). Recently, state-and-transition models have received considerable attention in restoration ecology because they are helpful to explain more adequately what happens under many restoration scenarios. These models, first proposed for range management purposes (Westoby et al., 1989), were created because of the inability that successional models have to effectively describe vegetation dynamics on rangelands (Laycock, 1991), which depend on several ecological processes (e.g., cyclic climatic conditions, grazing intensity, altered fire regimes) that could result in non-linear vegetation dynamics. Within the realm of restoration ecology, state-and-transition models have been proven useful based on the increased recognition that ecosystem dynamics can be complex and that ecosystems can exist in a number of different states, of which some are caused by human disturbance (Suding et al., 2004; Lindig-Cisneros, 2008).

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Around the world, managed landscapes are mosaics of different land-use types, and in some cases different management practices coexist for the same land-use. For example, agricultural lands are present under intensive, traditional, and/or organic management within the same watershed, with each type of management having contrasting environmental effects (Hendriks et al., 2000; Haas et al., 2001). Forests can also be managed with several different methods (see Mathey et al., 2005; Larsen and Nielsen, 2007; Puettmann and Ammer, 2007; and references therein), but again, within the same landscape, specific areas can be managed under sustainable and non-sustainable practices. Also, human dominated landscapes include heavily-altered systems, such as urbanization, that elevate the level of environmental heterogeneity within landscapes. Considering non-urbanized landscapes, restoration has become necessary to recover biodiversity and ecosystem services and, unless strict conservation is the final goal of management, the objective should be to create multi-functional landscapes (Lovell and Johnston, 2009). The restoration of multiple functions implies focusing on productive systems that, after restoration efforts are applied, should be sustainably managed. Therefore, the restoration of habitats within landscapes for sustainable purposes requires the generation of clear conceptual models that allow choosing and implementing management alternatives for optimizing cost-benefit relations and for providing practitioners with proper guidance. When the goal is to restore a productive system with or without areas for conservation, restoration models need to include not only ecological factors and processes, but also social dynamics and their implications.

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2. RESTORATION FOR SUSTAINABLE MANAGEMENT OF CONIFER FORESTS IN WESTERN MEXICO An adaptive restoration program for research and the implementation of productive restoration was started in 2001 by RL-C in the Comunidad Indígena de Nuevo San Juan Parangaricutiro (referred as Nuevo San Juan hereafter), located in the State of Michoacán (West-central Mexico). This adaptive restoration program was implemented with the following goals: (1) to enhance forest reestablishment in areas covered with tephra (volcanic ash) through the implementation of techniques that could be implemented by local communities; and (2) to facilitate the reestablishment of native vegetation in abandoned agricultural fields to recover biodiversity. Pine and oak-pine forests dominate this region of West-central Mexico, where the communal lands of Nuevo San Juan are located. The community's forests cover an area of 11,694 ha and are managed for timber extraction under sustainable forestry practice (Velázquez et al., 2003). This landscape consists of a mosaic of stands managed for sustainable timber extraction, protected riparian areas, areas kept exclusively for conservation, agricultural fields, and disturbed sites known as arenales (bare areas created by deposition of volcanic ash from the eruption of the Paricutín volcano between 1943 and 1952 in agricultural fields (Flores, 1945; Foshag and González, 1956). In 2008, RL-C proposed a state-and-transition model for understanding dynamics of forests that suffered the effects of the Paricutín volcano (Figure 1). This model depicts the dynamics among forests, defined by their use (either conservation or sustainable timber

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extraction), and agricultural lands following linear successional dynamics; and that between arenales and forests, non-linear state-and-transition dynamics occur. This model is supported by different lines of evidence described in detail elsewhere (Lindig-Cisneros, 2008), with the main pieces of evidence being: (1) tree recruitment not occurring in arenales, since the eruption of the Paricutín volcano that ended more than 55 years ago; (2) great limitations for recruitment of understory plant species; (3) close relationships between plant establishment and the physical characteristics of the tephra - mainly its depth and the high surface temperature, close to 70oC, that can reach during the dry season at midday; and (4) the facilitation effects of nurse plants and planting of late successional species in restoration practices set in agricultural lands (Lindig-Cisneros et al., 2002; Gil-Solórzano et al., 2009).

Figure 1. Model of transitions in a managed landscape. In Nuevo San Juan, the arenales represent a stable state because non-linear dynamics maintain the plant community structure and can change only through restoration. Agricultural lands, through linear dynamics, can transit to forests.

Although this model is useful to understand the ecological dynamics of this managed landscape in particular, it fails to reflect that agricultural lands, in terms of management, are as stable as arenales, as long as the stakeholders consider that the agricultural use is the most profitable. The model also fails to explicitly address the role of key factors in the restoration process, such as the degree of degradation and the degree of the restoration effort, factors addressed in the Zedler's ecological restoration spectrum model (Zedler, 1999). These factors determine the expectations that stakeholders create in relation to the restoration process and its goals. Therefore, if the degree of degradation is too high or the restoration effort needed considerable, the goals might be set low (e.g., recover part of the structure or specific

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functions), but if the degree of degradation is low or the effort needed also is low, goals can be ambitions (e.g. full ecosystem recovery). Consequently, stable states (SS) can exist in managed landscapes, either because non-linear ecosystem dynamics prevail, or because social interests maintain them for long periods of time. We propose that for restoring productive landscapes, especially for sustainable production, a state-and-transition model that takes into account human-maintained stable states (HMSS) should be considered. In such a model, the driving force of restoration is to create and maintain a productive landscape that ought to preserve and recover biodiversity and ecosystem services, including provision services, such as food production. In this new model (Figure 2), stable states can arise either as SS or HMSS, and although each is maintained through different processes, transitions may occur only if the benefits expected from the outcome of the restoration effort are considered higher than the benefits obtained by the current state. In our study area, restoration efforts in the arenales have yielded native pine plantations with species-poor understories and low value as habitat for fauna. However, stakeholders value the restored vegetation because, in a broad sense, the land can be incorporated into sustainable timber production scheme. In contrast, abandoned agricultural fields can be restored using nitrogen-fixing nurse plants resulting in more complex habitats with species-rich understories (Diaz-Rodriguez et al., 2012) and suitable habitat for forest-dwelling birds (MacGregor-Fors et al., 2010). However, the use of nurse plants to accelerate the restoration process was less effective than we expected, because sustainable timber production, not biodiversity restoration, was the driving force for restoration. Despite limited emphasis on species richness, enhancing biodiversity would help Nuevo San Juan keep their sustainable forest certificate.

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3. PLANT RESTORATION EXPERIENCES IN NUEVO SAN JUAN As part of the adaptive restoration program in Nuevo San Juan, we conducted a series of experiments in order to propose general guidelines for the restoration of degraded lands in the landscape. In these experiments we evaluated the effect that pine bark mulching had on the survival of three native conifer species (i.e., Pinus pseudostrobus, P. montezumae, Abies religiosa) planted in two degraded sites (i.e., abandoned agricultural fields, arenales). We also assessed the effectiveness of a leguminous shrub (i.e., Lupinus elegans) to: (1) improve soil conditions of abandoned agricultural fields and arenales; (2) increase survival and growth of native coniferous species through nurse-plant effects; and (3) enhance plant diversity within restored sites by facilitating the establishment of other vascular plant species (BlancoGarcía et al., 2011; Diaz-Rodriguez et al., 2012). We used L. elegans for these experiments, as it is an abundant leguminous shrub across the bioregion, exhibits a high nitrogen-fixing capacity (desirable in sites that are depauperate in nutrients), is fast-growing, and its propagation requirements are fully described (Medina-Sanchez and Lindig-Cisneros, 2005; Alvarado-Sosa et al., 2007). Because different disturbance agents were involved in the degradation of the habitats of Nuevo San Juan, we also considered the effort needed to achieve restoration goals at each location.

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Figure 2. Conceptual model for ecological restoration merging state-and-transition and spectrum models considering stakeholders expectations. SS = stable state; HMSS = human-maintained stable state.

Among degraded lands, abandoned agricultural fields showed moderate levels of degradation, exhibiting low understory plant richness, low soil nutrient concentrations, and no forest cover. Results of our studies suggest that P. pseudostrobus and P. montezumae survive at higher rates than Abies religiosa, a shade-tolerant species with a mild survival rate. In this way, it is preferable to perform restoration activities within abandoned agricultural fields using several native conifer species in Nuevo San Juan. Moreover, using L. elegans as a nurse plant promotes plant species richness, enhances forb and shrub composition similarity between agricultural fields and nearby forests, amends soil chemical properties (i.e., nitrogen content), and increases total nitrogen content of the soil. Thus, a relatively low effort was needed to restore abandoned agricultural fields to vegetation that resembled the composition, structure, and function of the restoration target (Blanco-García et al., 2011; Diaz-Rodriguez et al., 2012). Results from experiments carried out in arenales contrast with those described for agricultural lands. The nurse effect of L. elegans did not develop because of low survival rates for the legume. Instead, the mechanical extraction of the volcanic ash and the addition of an organic mulch layer were the most effective restoration tools for increasings survival of native conifer species. One noteworthy aspect of restoring arenales is that these sites, being formerly agricultural lands, usually are located in low-lying areas and small valleys that suffer severe frost during winter. Under such conditions, Pinus montezumae, which is adapted to frost, had the highest survival rate (Viveros-Viveros et al. 2007).

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4. ZOOLOGICAL EVIDENCE As stated in the first section of this chapter, restoration efforts are required to change the state of degradation of habitats under several environmental conditions (Paul et al., 2004). However, not all degraded habitats respond equally to restoration, as restoration practitioners can find their goals met with the same amount of actions in some sites compared to others where their goals are simply not reached (Suding et al., 2004). As vegetation plays a crucial role for animals by providing feeding, nesting, resting, and hiding resources (Murdoch et al., 1972; Gagné et al., 1999; Díaz et al., 2005), restoration efforts that mold vegetation structure and composition should be reflected on the zoological component of restored sites. A recent review gathered an important sample of papers focused on the zoological component of restored areas (Majer, 2009). Previous studies have demonstrated that animals, from benthic invertebrates to birds, generally respond positively to restoration efforts (Ford et al., 2000; Seigel et al., 2005; Hosbon et al., 2007; Aerts et al., 2008; Larkin et al., 2008). However, because restoration practices involve the modification of habitats, they can also have site-specific negative impacts on native animals. For example, Ford et al. (1999) show that fire, as a management tool, can have negative impacts on important components of salamander habitat, such as leaf litter. Also, birds can be affected by restoration in diverse ways, depending on the type of the restored habitats (Fletcher and Koford, 2003; Smiley et al., 2007) and the strategies implemented to carry out the restoration effort (Davis et al., 2000; Twedt et al., 2002). A current study in Nuevo San Juan shows that when vegetation structure and diversity are triggered by restoration efforts including more than one activity (e.g., planting both pine trees and nitrogen fixing nurse-plants), bird communities from restoration plots are richer than those from reforestation ones, while restoration plots within areas where restoration practices did not meet all the goals achieved in the latter showed very similar bird communities in both restoration and reforestation plots (DOrtega-Álvarez 2010). One restored plot that has achieved the most intended restoration goals (e.g., quick tree growth, high plant diversity) within Nuevo San Juan is San Nicolás (; Blanco-García et al., 2011; Diaz-Rodriguez et al., 2012). Where this plot is located, several habitat conditions are present, mainly cropfields, conifer reforestation plots (without any other restoration practice), a conifer restoration plot (including other restoration practices, such as the inclusion of nitrogen-fixing nurse plants), and forest remnants. When we evaluated bird community responses to both control habitats (former-state: cropfields, natural-state: forests), we found that bird communities were richer in both restoration and reforestation plots than cropfields. While bird abundances were low in cropfields, reforestation plots, and the restoration plot, bird communities recorded in the restoration plot showed highly even bird communities, and lowest dissimilarity of bird community composition was found, compared to forest remnants. Thus, results of our study support the idea that, when restoration efforts quickly enhance both vegetation structure and plant species richness, bird communities can also benefit, even withing a 5 year period (MacGregor-Fors et al., 2010). However, further studies are needed to address the detailed population responses to restoration practices under different circumstances to better comprehend the long-term effects of restoration practices on animals, and the type of actions needed to cross thresholds and transition from one environmental states to another.

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5. IMPLICATIONS FOR LANDSCAPE MANAGEMENT Our experience at Nuevo San Juan has shown that it is useful to consider production landscapes as mosaics of land uses that are stable either because: (1) they are stable states (SS) in the strict ecological sense (Schroder et al. 2005; Suding et al. 2004) and exist because ecosystem dynamics are non-linear by nature; or (2) because they are human maintained stable states (HMSS) through direct and continuous human intervention, as in the case of open pastures for grazing or agricultural land that need to be weeded to prevent secondary succession. In Nuevo San Juan, most states are HMSS, since agricultural lands and pastures would revert to wooded lands, if abandoned and ungrazed, through secondary succession. When agriculture or grazing is intense, or where native vegetation remnants are distant, secondary succession will proceed, although slowly. However, the SS found in arenales arose in our study area following the deposition of volcanic ash on agricultural lands. Although this was a rare event, there are other environmental scenarios that can create stable states in human dominated landscapes, even when linear dynamics naturally prevail. The most ubiquitous examples of the latter are plant invasions of disturbed habitats that prevent establishment of native species (Brown et al., 2006; Davis et al. 2005). From a management perspective, the barriers that prevent transitions between alternative states can be difficult to overcome, and they represent serious restoration challenges. Arenales are a good example, as the physical condition of volcanic ash prevents plant establishment, and our experience indicates that only the removal of deposits deeper than 60 cm will allow plant recovery (Gómez-Romero et al., 2006). After volcanic ash removal, trees can establish, but the understory canopy remains open for at least 6 years after the intervention, and the resulting plantation is of poor quality for native fauna. Nevertheless, because the expectations of the stakeholders are related to sustainable forest production for the arenales, this partial restoration is carried on, driving a SS into a HMSS. In areas not affected by volcanic ash deposition, other factors have determined the change of management practices. In agricultural lands, some have been reforested for sustainable timber production, either because of low crop yields or lack of attractive prices for the product, since prices fell in México after the North American Free Trade Agreement was signed (Corneluis and Martin, 1993). In abandoned agricultural fields, the seeding of a native legume species can increase survival and growth of some tree species, increase understory diversity (Blanco-García, 2010) and create habitat for birds (MacGregor-Fors et al., 2010), faster than abandonment or reforestation would do. Therefore: (1) SS challenge managers with ecological barriers that have to be overcome to achieve restoration goals, which requires costly investments of energy and resources; and (2) HMSS will remain “stable” as long as the stakeholders consider the benefits of current practice higher than the benefits that can be expected from the outcome of a restoration effort (Figure 2). Nevertheless, this leaves two open questions: (1) how should decisions be made in order to manage complex landscapes for sustainable use?, and (2) what is the role of restoration under such framework? From our perspective, what is needed is a common criterion for assessing the impact of different management practices on the environment. We propose that biodiversity should be used as the main criterion, because it is already used for the evaluation of conservation and restoration outcomes, and even used for agroforestry system designs.

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Although ecosystem services have received recent attention for evaluating production systems, relying on ecosystem services as the criteria could be flawed and misleading because relationships between management regimes and ecosystem services are poorly understood (Bennet and Balvanera 2007) and hardly measurable. If biodiversity is considered as the main criterion to evaluate land management procedures, the role of restoration is to provide: (1) ways to increase biodiversity faster than natural succession would allow in ecosystems that follow linear dynamics; (2) to provide ways to overcome barriers for ecosystems that follow non-linear dynamics; and (3) to provide stakeholders with tools to increase biodiversity in their productive landscapes. By incorporating the expectations of stakeholders into land management models, including ecological restoration, the degree of degradation and the efforts needed to achieve ecological restoration with the nature of the dynamics that the ecosystems follow, a socio-ecological state-and-transition model arises (Figure 2). Managers can thus incorporate social aspects (such as market forces or different views of nature) into the management of complex landscapes.

ACKNOWLEDGMENTS We thank the Comunidad Indígena de Nuevo San Juan Parangaricutiro for their support and Joy B. Zedler for her valuable comments, which improved the clarity and quality of our manuscript. Being part of the Posgrado en Ciencias Biológicas of the Universidad Nacional Autónoma de México R.O-A. received a a Master's scholarship (327503).

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REFERENCES Aerts, R., Lerouge, F., November, E., Lens, L., Hermy, M. & Muys, B. (2008) Land rehabilitation and the conservation of birds in a degraded Afromontane landscape in northern Ethiopia. Biodivers Conserv, 17, 53-69. Alvarado-Sosa, P., Blanco-García, A. & Lindig-Cisneros, R. (2007) Test of alternative nursery propagation conditions for Lupinus elegans Kunth plants, and effects on field survival. Rev Fitotec Mex, 30, 201-204. Bennet, E.M. & Balvanera, P. (2007) The future of production systems in a globalized world. Front Ecol Environ, 5, 191-198. Blanco-García, A., Sáenz-Romero, C., Martorell, C., Alvarado-Sosa, P. & Lindig-Cisneros, R. (2011) Nurse-plant and mulching effects on three conifer species in a Mexican temperate forest. Ecol Eng, 37, 994-998. Bradshaw, A. D. (1984) Land restoration: now and in the future. P Roy Soc Lond B Bio, 223, 1-23. Brown, K.A., Scatena, F.N. & Gurevitch, J. (2006) Effects of an invasive tree on community structure and diversity in a tropical forest in Puerto Rico. For Ecol Manag, 226, 145-152. Cornelius, W.A. & Martin, P.L. (1993) The Uncertain Connection: Free Trade and MexicoU.S. Migration. Current Issue Briefs, Center for U.S.-Mexican Studies, San Diego, USA: U.C. San Diego.

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Davis, M. A., Peterson, D. W., Reich, P. B., Crozier, M., Query, T., Mitchell, E., Huntington, J. & Bazakas, P. (2000) Restoring savanna using fire: impact on the breeding bird community. Restor Ecol, 8, 30-40. Davis, M.A., Bier, L., Bushelle, E., Diegel, C., Johnson, A. & Kujala, B. (2005) Nonindigenous grasses impede woody succession. Plant Ecol, 178, 249-264. Díaz, I. A., Armesto, J. J., Reid, S., Sieving, K. E. & Willson, M. F. (2005) Linking forest structure and composition: Avian diversity in successional forests of Chiloé Island, Chile. Biol Conserv, 123, 91-101. Díaz-Rodríguez, B., Blanco-García, A., Gómez-Romero, M. & Lindig-Cisneros, R. (2012) Filling the gap: restoration of biodiversity for conservation in productive forest landscapes. Ecol Eng, 40, 88-94. Fletcher, R. J. & Koford, R. R. (2003) Changes in breeding bird populations with habitat restoration in northern Iowa. Am Midl Nat, 150, 83-94. Flores, R. T. (1945) El Paricutín, Estado de Michoacán, México. Tomo XIV. México: Imprentas Universitarias, Universidad Nacional Autónoma de México. Ford, W. M., Menzel, M. A., McGill, D. W., Laerm, J. & McCay, T. S. (1999) Effects of a community restoration fire on small mammals and herpetofauna in the southern Appalachians. Forest Ecol Manag, 114, 233-243. Ford, W. M., Russell, K. R. & Moorman, C. E. (2000) The Role of Fire in Nongame Wildlife Management and Community Restoration: Traditional Uses and New Directions, Proceedings of a Special Workshop. Nashville, Tenessee: United States Department of Agriculture, Forest Service, Northeastern Research Station. Foshag, W. F. & González, R. J. (1956) Birth and development of Paricutin Volcano, México. Bulletin of the Geological Survey, 965-D, 355-489. Gagné, N., Bélanger, L. & Huot, J. (1999) Comparative responses of small mammals, vegetation, and food sources to natural regeneration and conifer release treatments in boreal balsam fir stands of Quebec. Can J Forest Res, 29, 1128-1140. Gil-Solórzano, D., Lara-Cabrera, S. & Lindig-Cisneros, R. (2009) Effects of organic matter added to sand deposits of volcanic origin on seedling recruitment. Southwest Nat, 54, 439-445. Gómez-Romero, M., Lindig-Cisneros, R. & Galindo-Vallejo S. (2006) Effect of tephra depth on vegetation development in areas affected by volcanism. Plant Ecol, 183, 207-213. Haas, G., Wetterich, F. & Kopke, U. (2001) Comparing intensive, extensified and organic grassland farming in southern Germany by process life cycle assessment. Agr Ecosyst Environ, 83, s43-s53. Hendriks, K., Stobbelaar, D. J. & van Mansvelt, J. D. (2000) The appearance of agriculture: An assessment of the quality of landscape of both organic and conventional horticultural farms in West Friesland. Agr Ecosyst Environ, 77, 157-175. Hobson, T., Herkert, J. R., Ware, P. R. & Randall, R. (2007) Wetland bird response to habitat restoration at Spunky Bottoms Preserve. In E. J. Heske, J. R. Herkert, K. D. Blodgett & A. M. Lemke (Eds.), Spunky Bottoms: Restoration of a Big-River Floodplain (pp. 37-39). Illinois: Illinois Department of Natural Resources. Larkin, D. J., Madon, S. P., West, J. M. & Zedler, J. B. (2008) Topographic heterogeneity influences fish use of an experimentally restored tidal marsh. Ecol Appl, 18, 483-496.

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Larsen, J. B. & Nielsen, A. B. (2007) Nature-based forest management: Where are we going? Elaborating forest development types in and with practice. Forest Ecol Manag, 238, 107117. Laycock, W. A. (1991) Stable states and thresholds of range condition on North American rangelands: A viewpoint. Journal of Range Management, 44, 427-433. Lindig-Cisneros, R. (2008) Models of alternate states for planning and implementing restoration of production systems in Michoacán, México. In K. Suding & R. Hobbs (Eds.), New Models for Ecosystem Dynamics and Restoration (pp. 311-322). U. S. A: Island Press. Lindig-Cisneros, R., Sáenz-Romero, C., Alejandre, N., Aureoles, E., Galindo, S., GómezRomero, M., Martínez, R. & Medina, E. (2002) Efecto de la profundidad de los depósitos de arena volcánica en el establecimiento de vegetación nativa en las inmediaciones del volcán Paricutín, México. Ciencia Nicolaita, 31, 47-54. Lovell, S. T. & Johnston, D. M. (2009) Creating multifunctional landscapes: How can the field of ecology inform the design of the landscape? Front Ecol Environ, 7, 212-220. MacGregor-Fors I., Blanco-García, A. & Lindig-Cisneros, R. (2010) Bird community response to different forest restoration efforts. Ecol Eng, 36, 1492-1496. Majer, J. D. (2009) Animals in the restoration process: progressing the trends. Restor Ecol, 17, 315-319. Mathey, A. H., Kramar, E. & Vertinsky, I. (2005) Re-evaluating our approach to forest management planning: A complex journey. Forest Chron, 81, 359-364. Medina-Sánchez, E. & Lindig-Cisneros, R. (2005) Effect of scarification and growing media on seed germination of Lupinus elegans H. B. K. Seed Sci Technol, 33, 237-241. Murdoch, W. W., Evans, F. C. & Peterson, C. H. (1972) Diversity and patterns in plants and insects. Ecology, 53, 819-829. Ortega-Álvarez, R. (2011) Respuesta de las aves ante diferentes escenarios de restauración en bosques templados. M. Sc. Thesis. Morelia, Michoacán; Universidad Nacional Autónoma de México. Palmer, M. A., Ambrose, R. F. & Poff, N. L. (1997) Ecological theory and community restoration ecology. Restor Ecol, 5, 291-300. Paul, J. R., Randle, A. M., Chapman, C. A. & Chapman, L. J. (2004) Arrested succession in logging gaps: is tree seedling growth and survival limiting? Afr J Ecol, 42, 245-251. Puettmann, K. J. & Ammer, C. (2007) Trends in North American and European regeneration research under the ecosystem management paradigm. European Journal of Forest Research, 126, 1-9. Schroder, A., Persson, L. & De Roos, A. M. (2005) Direct experimental evidence for alternative stable states: a review. Oikos, 110, 3-19. Seigel, A., Hatfield, C. & Hartman, J. M. (2005) Avian response to restoration of urban tidal marshes in the Hackensack Meadowlands, New Jersey. Urban Ecosystems, 3, 87-116. Smiley, P. C., Maul, J. D. & Cooper, C. M. (2007) Avian community structure among restored riparian habitats in northwestern Mississippi. Agr Ecosyst Environ, 122, 149156. Suding, K. N., Gross, K. L. & Houseman, G. R. (2004) Alternative states and positive feedbacks in restoration ecology. Trends Ecol Evol, 19, 46-53. Twedt, D. J., Wilson, R. R., Henne-Kerr, J. L. & Grosshuesch, D. A. (2002) Avian response to bottomland hardwood reforestation: the first 10 years. Restor Ecol, 10, 645-655.

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Velázquez, A., Torres, A. & Bocco, G. (2003) Las Enseñanzas de San Juan: Investigación Participativa para el Manejo Integral de Recursos Naturales. México: Instituto Nacional de Ecología. Viveros-Viveros, H., Saenz-Romero, C., Lopez-Upton, J. & Vargas-Henandez, J.J. (2007) Growth and frost damage variation among Pinus pseudostrobus, P. montezumae and P. hartwegii tested in Michoacan, Mexico. For Ecol Manag, 253, 81-88. Westoby, M., Walker, B. H. & Noy-Meir, I. (1989) Opportunistic management for rangelands not at equilibrium. J Range Manage, 42, 266-274. Zedler, J. B. (1999) The ecological restoration spectrum. In W. Streever (Ed.), An International Perspective on Wetland Rehabilitation (pp. 301-318). The Netherlands: Kluwer Academic Publishers.

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In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 8

RECLAMATION OF DEGRADED LAND THROUGH FORESTRY PRACTICES Rajeev Pratap Singh1,*, Sonu Singh2, Anita Singh3 and Puneet Singh Chauhan4 1

Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India 2 Ministry of Environment and Forests, CGO Complex, Lodhi Road, New Delhi, India 3 Department of Botany, Allahabad University, Allahabad, India 4 National Botanical Research Institute, Rana Pratap Marg, Lucknow, India

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ABSTRACT During the past few decades, global population is increasing at an exponential rate. As a consequence of that, more productive areas are needed to fulfill the increasing demand of food, fiber, livelihood and other important ecosystem services. On the contrary, due to various measures, degradation of effective and productive landmasses has been seriously increased, and become a burning issue at presently worldwide. Different socio-economic challenges (e.g. population burst, uncontrolled urbanization, improper resource management etc.) and environmental challenges (e.g. climate change, soil erosion etc.) are constantly imposing threats to land quality. The only way to survive under these increasing multidimensional challenges to restore the degraded land mass through sustainable practices. Several studies have proven that proper agro-forestry practices can check soil erosion to some extent; increase soil fertility; reduce salinity, alkalinity, acidity and desertification, etc. This chapter mainly demonstrates the significant causes and types of land degradation for possible sustainable restoration strategies using forestry practices and their potential benefits effects on environment.

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INTRODUCTION Land, a non-renewable resource, is vital for all primary production systems. Pastures and crops are the two most extensive forms of land use, occupying 25% and 12% of the global land surface, respectively (Ramankutty and Foley, 1999; Asner et al., 2004). The land also serves as storage for water and nutrients required for all living micro- and macro-organisms. However, fast depletion of natural resources such as forest soil, water, minerals and exponential increase in population rate are the serious constraints in environmental conservation, as well as land restoration. The increasing demand for food, energy and other human requirements depends upon the preservation and improvement of the productivity of land; but, as above said, land resources are limited. India, alone is the home of 16 % of global population; however, it accounts for only 2.42 % of the total land area. The per capita availability of land has declined from 0.89 hectare in 1951, to 0.37 hectare in 1991 and is projected to slide down to 0.20 hectare in 2035 (Yadav, 2000; Nagaraja, 2009). As far as agricultural land is concerned the per capita availability of land has declined from 0.48 hectare in 1951, to 0.16 hectare in 1991 and is likely to decline further to 0.08 hectare in 2035 (Nagaraja, 2009). In India, Green Revolution brought about technological breakthrough, which led to the use of short duration high yielding varieties helping intensive use of land in a year, increasing area brought under irrigation and prolific use of chemicals such as fertilizers and pesticides. It has been lately recognized that the increasing efforts to raise agricultural production has cost us dearly in the form of land and water deterioration. Large scale ecological losses, specifically species biodiversity, were reported in crop land, grass land and forest land, due to soil erosion, increasing alkalinity and salinity of soil, micronutrient deficiency, water logging and fast depletion and contamination of ground water. These factors limit future utilization of land and water resources. Many reckless anthropogenic activities, viz. rapid industrialization, improper urbanization and unsustainable resource management, have also created a crisis globally. We, the human beings, belonged to mainly two different worlds; one is the world of natural resources like - soil, water, air and so on, which we inherit; and the other is the world of social, economic and political institutions, which we create. So, we should be very much careful, because both the worlds are inter-dependent, and if the primary world of natural resources degrades then the secondary world of human civilization cannot be safe enough for a longer period. However, unfortunately for several decades, the major natural resource, i.e. global landmass, is suffering from multidimensional challenges and resulting in severe degradations. According to Singh (1994), land degradation refers to the means loss in the given land capacity to support growth of useful plants on a sustained basis. Land degradation also refers to means loss of biological or agricultural productivity or erosion in the land’s capacity to support desirable vegetation (i.e. crops, forests, pastures) and to maintain the yield level over the years of use (Kiran et al., 2009). According to Fitzpatrick (2002) land degradation (soil salinity, sodicity, acidity and erosion) is the systematic decline in the quality of land resulting from a mismatch between land use and land quality. It is the outcome of different natural processes, but is generally accelerated by anthropogenic activities. Land degradation has been observed as a critical problem in most of the third world countries. Due to land degradation; quality of land is declining or there is decline in potential productivity of land. Several factors or/and

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combination of factors results in degradation of soil, water and vegetation resources and restrict their use or production capacity. Several million hectares of barren sodic soils occur in arid and semiarid regions of India, Pakistan, Australia, United States, and many other countries around the world (Tripathi and Singh, 2005). Currently, nearly 1.9 billion hectares of land worldwide (an area approximately the size of Canada and the USA) are affected by land degradation (UN, 1997).

Source: Indian forester, page 626, 1992. Figure 1.

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More than 90% of the population of Nepal and about 65-70 per cent of the population in India is dependent on agriculture for their livelihoods (LRMP, 1986; Mandal and Ghosh, 2000). According to United Nations (1992), the survivals of more than 900 million people in about 100 countries are at present directly and badly affected by land degradation process. According to Eswaran and Kapur (1997), food security is directly linked to the ability of land to support its populations. Therefore food security of mankind will be threatened and the capability of poor nations to boost their assets through improved productivity will be impeded, unless the current rate of land degradation is slowed and reversed and throughout world many regions will never accomplish food security. The major constraints against the establishment and growth of plants are attributed to structural, chemical, nutritional, hydrological, and microbial deterioration of soils (Gupta and Abrol, 1990; Naidu and Rengasamy, 1993; Sumner, 1993; Garg, 1998). Land degradation may occur through different physical, chemical and biological processes which are directly or indirectly induced by human activities. These include soil erosion, compaction, acidification, leaching, salinity, decrease in cation retention capacity, depletion of nutrient, reduction in total biomass carbon and decline in biodiversity. Soil structure is major factor for all forms of degradative processes. It also affects the provision of ecosystem services. Human activities are responsible not only for the degradation of land but also important for improvement of land through prevention, rehabilitation and reclamation (MoEST, 2008). Larger areas of productive land mass are required in many developing countries to meet the increasing demands for food, fiber and raw materials. Now only about 3 % of total geographical area is highly productive and around 19 % of the total area is low or medium productive. Every year we are losing about 5 to 7 million hectare agricultural lands due to several natural and anthropogenic factors. One possible means to achieve land requirement for increasing food, fodder and shelter is to reclaim its significant amounts of degraded land. Man is coming to the limits of growth and unless deliberate calculated steps are taken to change the course action, he will endanger his own existence. Improper land use pattern and extensive irrigation have contributed significantly to the soil degradation. Irrigation is blessing when it makes the arid lands productive, but it becomes a curse when faulty irrigation system makes the soil saline and alkaline. According to the National Remote Sensing Agency and Forest Survey of India, 60% of the total area under cultivation is substantially degraded. Most of this damage is in the form of loss of topsoil. With all these facts the present chapter will focus on the causes and types of land degradation and their possible sustainable restoration strategies using forestry practices and their potential benefits effects on environment.

1. CAUSES OF LAND DEGRADATION AND ITS TYPES Before going to in details of the causes of land degradation and its pattern; we should have a look at the present land use pattern at global level. It was quite interesting to find that, out of the total 328.05 million hectare of geographical area of India, about 143.0 million hectares is net cultivated area (MoEF, 2009) (Table 1). Of this, about 57 million hectare (40%) is irrigated and the remaining 85 million ha. (60%) is rain fed. This area is usually subject to wind and water erosion and is in different stages of degradation due to intensive

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agricultural production. The erosion rates are reported to be in the range of 5 to 20 tones/hectare (up to 100 t ha -1) in India (MoEF, 2009). Still India has 40 million ha waste lands which is potentially arable, but non-productive because of one constraint or another (Table 1). Table 1. Land use utilization statistics of India (Million hectares)

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Total Geographical area Total area for which land statistics are available Area under urban and non agricultural use Area which are barren and uncultivable (eg Snowbound, rocks etc) Area under forests and permanent pasture Culturable waste / potentially arable Agricultural land

Area (M ha) 328.05 305.51 18.00 21.00 83.00 40.00 143.00

Therefore, it needs improvement in terms of its productivity per unit of land, and per unit of water for optimum production. Rainfed agriculture is characterized by low levels of productivity and low input usage. Crop production is subjected to considerable instability from year to year due to its dependence on rainfall, which is considerably erratic and variant in space and time. Major developing and under developed countries worldwide, which mainly depend on agriculture for their economical stability, also demonstrate a land use pattern like that of India. More than 200 million of the rural people globally live in the rainfed regions. These risk prone areas exhibit a wide variation and instability in yields. Land degradation may occur through different physical, chemical and biological processes which are directly or indirectly induced by human activities (Figure 1). These include soil erosion, compaction, acidification, leaching, salinization, decrease in cation retention capacity, depletion of nutrient, reduction in total biomass carbon and decline in biodiversity. Soil structure is major factor for all forms of degradative processes. It also affects the provision of ecosystem services. Anthropogenic activities are mainly responsible, not only for the degradation of land but also important for improvement of land through prevention, rehabilitation and reclamation (MoEST, 2008). The major causes of land degradation is the conversion of medium to low productive agricultural land to other uses like industries, brick kiln, road etc. The practice of intensive agriculture is also major cause of land degradation. The factors responsible are • • •

•

Climate: higher evaporation than precipitation, drought, short duration rain fall with high intensity, high velocity winds, storms etc. Soil factors: Slope, course texture, water impermeability, compactness etc Management factors: Improper land use and cropping system without soil conservation measures, excessive use of chemicals, shifting cultivation, deforestation etc Socio economic and policy factors: Population pressure, poverty, declining land: population ratio, ineffective land policies etc.

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The various types of land degradation which finally results in degraded land are wind erosion, water erosion, overgrazing, dryland salinity, soil acidification, irrigation salinity and water logging, replacement of natural vegetation with pasture, soil structure decline and clearing of natural vegetation. Water logging, soil crusting, compaction, desertification are sometimes enlisted under physical degradation and salinization, sodification, acidification, nutrient removal under chemical degradation. •

•

•

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•

•

•

•

•

Wind erosion: When soil is devoid of vegetation, it is left exposed to other elements, leaving it bare and loosening the soil particles. The top soil is then blown away by air, leaving poorer quality sub-soil to remain. Water Erosion: Water erosion is similar to wind erosion, except instead of wind removing the particles; it is due to the force of running water and heavy rainfall. Such events include flash flooding, where water due to abrupt rainfall can sweeps down, taking with it everything in its path. They uproot trees, move boulders and demolish bridges and buildings, along with the precious topsoil. These floods are very dangerous. Overgrazing: Overgrazing is a common problem in many parts of world. It is caused by animals, generally sheep, cattle, or other wild animals, all concentrated in the one area, all feeding on the grass and shrubs. Grass and shrubs hold the soil firmly together. The removal of grass and shrubs leaves the soil bare and susceptible to wind and water erosion. The soil can be broken up or compacted by hooves, this makes the problem worse. It also increases runoff where water is not absorbed into the ground but it runs off. Dryland Salinity: When land is cleared from all the natural vegetation, groundwater can slowly rise to the surface of the soil because trees intercept the rain water, therefore the water table doesn’t rise. The water table rises, as the roots from trees keep it down. The water is very salty and only certain trees can withstand the salinity level. When the water table rises, the salt kills trees and crops that cannot survive the concentration of salt in the water. When the water has evaporated, all that remains is the salt, therefore rendering the soil useless. Soil Acidification: When certain chemicals are used on the soil, for various reasons including pesticides; removal of salt from the surface and the soil; acid rain; the growth of certain crops; certain animal wastes; etc, these chemicals are often absorbed into the soil and become part of the soil-structure. With these chemicals now part of the soil, the soil may become acidic and therefore crops and pastures will not grow. Soil acidification can lead to a productivity decline up to and equal to 50%. Irrigation Salinity and Water logging: Irrigation salinity is when the irrigation water, used to provide water for crops and pasture, seeps down to the water table, with all the dissolved salts, rises and kills the crops and grass, as they are not used to the salty soils. Water logging: It is very similar to irrigation salinity. The only thing that is different is that the farmer irrigates his crops excessively, to the point whereby the water then seeps down to the water table whilst all this extra water saturates the surface, there is more water in which the salts are able to be dissolved. The Replacement of Natural Vegetation with Pasture: With new pasture, come new irrigation and more water. The natural vegetation is more adapted to the salinity of

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the soil and the water table. Most native trees have deep roots that keep the water table down, but if these deep roots are removed then the water table will rise due to more water and by the time that the water table reaches the roots, the pasture will die and the water evaporate, leaving behind salt pans, a crusty formation of salt on the surface. With saltpans on the surface, it is very hard to try and remove the salt from the surface and the soil. Soil-Structure Decline: Soil-structure is a complex soil composition. This comprises of air, organic matter, water, mineral particles, nutrients, etc. The different types of organic matter, mineral particles and nutrients make the soil-structure types more diverse. Soil-structure declines when all these different types of nutrients and organic matter are somehow drawn from the soil and limited nutrients are left in the soil. Things that can cause soil-structure decline, are erosion of any kind, some agricultural cultivation practices, over worked soils that do not have time to replace nutrients etc; the use of pesticides can affect the soil-structure, as the insects’ dead bodies, and wastes contribute to the soil-structure diversity; and the chemicals in some pesticides may have effects on the soil and the structure of the soil, short-term and long-term.

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The term ‘desertification’ does not refer that; deserts are steadily advancing or taking over neighboring land. According to United Nations Convention, ‘desertification’ is a process of "land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities". Patches of degraded land may develop hundreds of kilometers far from the nearest desert. These patches can expand and join together, creating desert-like conditions. Desertification contributes to other environmental crises, such as the loss of biodiversity and global warming.

2. LAND DEGRADATION - A GLOBAL CONCERN Land degradation affects an estimated 24% of the global land area (Bai et al., 2008). Total world land mass exceeds 13 billion hectare but less than 50 % can be used for agricultural activity including grazing (Hasan and Alam, 2006). Potentially arable land accounts about 3031 million ha out of which 2154 million ha are in developing countries and rest i.e. 877 million ha are in developed countries (Table 2). About 1461 million ha land is cultivated of which 784 and 677 million ha falls in developing and developed countries respectively (Dudal, 1982). The information on the extent of soil degradation in India has been assessed by various agencies. The estimates of these agencies vary widely i.e. 63.9 187.0 million hectare due to different approaches in defining degraded soils and adopting various criteria for delineation. According to National Bureau of Soil Survey and Land Use Planning 66 % of India’s geographic area (around 192 million hectare) is at varying stages of degradation (Figure 2) (Balooni and Singh, 2003).

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Figure 2. As per National Bureau of Soil Survey & Land Use Planning, Nagpur – 2005. A, State wise distribution of total geographical area of India. B, State wise representation of percentage of total degraded lands.

According to Chambers et al. (1989) the total degraded land area accounts to be nearly 84 m ha, comprising 35 m ha of private cultivated lands (field bunds and boundaries) and 49 m ha of government-owned degraded lands, including village commons. All of this land is available for rehabilitation through afforestation. In a recent pioneering study sponsored by three United Nations agencies (FAO, UNDP and UNEP) the severity and costs of land degradation in South Asia was estimated. It was reported that the countries (India, Pakistan,

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Bangladesh, Iran, Afghanistan, Nepal, Sri Lanka and Bhutan) are losing at least US$10 billion annually as a result of losses resulting from land degradation (Pohit, 2009). This was equivalent to 2% of the region's Gross Domestic Product, or 7% of the value of its agricultural output. Economic impact of degradation of land is exceptionally severe in densely populated South Asia, and sub-Saharan Africa regions. Productivity loss is estimated about 36 million tons of cereal equivalent annually valuing at 5,400 million US$ via water erosion, and 1,800 million US$ due to wind erosion, in South Asia. According an estimation the total annual cost of erosion from agriculture in the USA is about 44 billion US$ every year, i.e. about 247 US$ per ha of cropland and pasture. Globally the annual loss of 75 billion tons of soil costs the world about 400 billion US$ every year, or approximately 70 US$ per person per year (Hasan and Alam, 2006). Table 3, shows that about 70% of the entire land of the world is under various types of degradation (Dregen and Chou, 1994). According to BARC (BARC, 1999), Bangladesh looses a substantial amount of production which accounts hundreds of billion takka per year. Table 2. Money spent by different agencies for wastelands development programme in India

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Ministry of Rural Areas and Employment Including Department of Wasteland Development Ministry of Environment and Forests Ministry of Agriculture and Cooperation Planning Commission National Bank for Agriculture and Rural Development (NABARD) State Soil Conservation Departments State Land Development Banks Private Investments (unconfirmed) Total

Rs. Million/year 12500 9060 3620 2600 500 3410 11060 7250 50000

Source: Report of Task Force on Wastelands Development in the IX Five Year Plan, May 1996, Ministry of Rural Areas and Employment, Government of India, New Delhi.

Table 3. Estimation of total degraded lands (million km2) worldwide Continent Africa Asia Australia and the Pacific Europe North America South America

Total area 14,326 18,814 7,012 1,456 5,782 4,207

Degraded area 10,458 13,417 3,759 0,943 4,286 3,058

% degraded 73 71 54 65 74 73

Total

51,597

35,922

70

Source: Dregne and Chou (1994).

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Figure 3. land degradations and its consequences.

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3. RECLAMATION OF DEGRADED LANDS There are number of alternative methods of reclaiming degraded land (Gautam et al., 1992). The selection of a reclamation technique depends on the types of degraded land, degree of degradation, and costs and benefits involved in the process. Afforestation has been identified as economically viable and ecologically appropriate method and must be implemented in a proper way depending on local physical and human environmental conditions. However, afforestation on a large scale requires huge investment (World Bank, 1993; Balooni and Singh, 2003, 2007). Some of the methods dealing with reclamation of degraded lands through forestry practices are

a. Reclamation of Degraded Land through Agroforestry Practices Agroforestry has attracted considerable interest in recent years as it can help low resource farmers with physical and socioeconomic constraints to maintain or increase agricultural productivity (Kidd and Pimental, 1992). Agroforestry is particularly beneficial in rainfed systems where high energy input and large scale farming is practically impossible. Agroforestry practices not only minimize the land degradation but also increases the overall production of the system. Cannell et al. (1996) proposed that agroforestry may increase productivity provided the trees capture resources that are underutilized by annual crops. The components of agroforestry exploit different vertical layers both above and below ground which signifies greater resource utilization efficiency for optimizing resource use. Ecologically sound agroforestry is a useful path, in comparison to chemical fertilizers, enhancing soil fertility leading to global food security and environmental sustainability. There are numerous advantages of agroforestry systems like these systems have higher productivity than mono-specific systems, especially on degraded sites (Young, 1991). In agroforestry practices trees can add a significant amount of nutrients into the soil. The

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productivity and fertility of soil is mostly related to the growth of nitrogen- fixing trees or deep-rooted trees and shrubs plantation of leguminous tree is encouraged as they fix a substantial amount of nitrogen from the atmosphere and also buildup soil organic matter. Rate of nitrogen fixation by leguminous herbs varies from 40-200 kg N ha-1 year-1 (Larue and Patterson, 1981; Gibson et al., 1982). Singh and Hazra (1995) reported that silviculture techniques help in increasing available nutrients (N, P and K), organic carbon and reducing pH and EC as compared to degraded land. Trees improve the physical properties like structure, porosity, and water holding capacity etc. of soil by addition of organic matter and also modify the temperature via shading and litter cover. Agroforestry systems have the potential to control erosion, improve soil fertility, and subsequently lead towards sustainable land use. It has been reported that financial returns generated from agroforestry system are usually much higher than return from continuous unfertilized food crops around the developing world. Although trees are expected to improve soil fertility, the extent to which different agroforestry practices depend on tree species, stocking level, growth rate and the input of litter. The general belief is that agricultural crops grow poorly beneath or near trees. This is considered an expression of competitive interaction between trees and crops grown together (Rao et al., 1998) and is viewed as a negative aspect of agroforestry. Indeed, this view has led to the argument that one should shy away altogether from simultaneous agroforestry systems, especially in drier climatic zones and focus on fallow rotations (Sanchez, 1995). Such arguments do not, however, consider the system’s productivity and value from a holistic viewpoint. Achieving synchrony in nutrient release through organic matter turnover is yet another challenging task. Below-ground interactions are the most important aspects concerning yield reduction in the semi-arid tropics where water is the prime factor limiting crop growth (Ong et al., 1991). Experiments at Machakos, Kenya involving root trenching and tree species such as Leucaena leucocephala (Govindrajan et al., 1996) demonstrated that alley cropping may adversely affect crop productivity in semi-arid environments because increased competition for water outweighs potential soil fertility benefits resulting from applications of tree mulch, nitrogen fixation or increased root turnover. Other studies have shown that regular pruning of the trees in alley cropping systems encourages the proliferation of fine roots in the surface soil horizons, so decreasing spatial niche separation between the tree and crop roots and hence the potential for complementarily in the use of below-ground resources (Noordwijk and Purnomosidhi, 1995). It is therefore important to select for trees with appropriate root architecture in order to achieve spatial complementarily and avoid major crop yield losses. Tree species for agroforestry practices are selected on the basis of potential survival growth, tolerance ability sodicity, and ameliorative capability without using chemical amendments (Khanduja et al., 1987). Trees have multiple functions in any ecosystems and there is no alternative in the maintenance of ecosystem balance. Success or collapse of the ecosystem management depends on the site conditions, selection of plant species, and planting techniques.

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Table 4. Plant species suitable for alkaline, sodic and acidic soil Soil Types Saline soils

Soil characteristics High salt content, high water table. pH < 8.2 > 7.0

Alkali or sodic soils

Contains excess soluble sodium salts capable of alakaline hydrolysis. pH > 8.2.

Acidic soil

 

 

 

 

 

Suitable plant species Atriplex, Prosopis, Tamarix, Casuarina, Kochia, Zizyphus, Salvadora and Acacia, Termnalia arjuna, Albizzia procera, Eucalyptus ‘hybrid’, Leucaena leucocephala, Plants that can tolerate more than pH 10.0 Prosopis jiliflora, Acacia nilotica, Casuarina equisetifolia, Tamarix articulata, Achras japot, Tamarix aphylaIa etc. Plants that can tolerate pH 9.1 to 10.0 Pitchecellobium dulce, Salvadora persica, Salvadora oleoides, Capparis decidua, Terminalia arjuna,Cordia rothii, Albizzia lebbek, Pongramia pinnata, Sesbania sesban, Eucalyptus tereticornis, Parkinsonia aculeata, Cassia carandus, Psidium guajava, Zizyphus mauritiana, Aegle marmelos, Emblica officinalis, Punica granatum, Phoenix dactylifera, Tamarindus indica, Syzygium cumuni, Eucalyptus microtheca, Casurina equisetifolia etc. Plants that can tolerate up to pH 9.0 Acacia auriculiformis, Azadirachta indica, Melia azaderach, Populus deltoides, Grewia asiatica, Vitis vinifera, Mangifera indica, Kijellea pinnata, Moringa oleifera, Grevillia robusta, Butea monosperm, Pyrus communis, Sapindus laurifolius, Ficus sp. etc. Well adapted Alnus nepalensis, Parkia javanica, Parkia facataria, Michelia oblonga, Melenia arborea Moderately adapted Acacia auriculiformis, Michelia alba, Michelia lenigata Less adapted Leucaena leucocephala, Robinea pseudoacacia, Cryptomeria japonica, Cryptomeria torulosa, Pinus kesiya etc

Source: Hasan and Alam, (2006); Dagar et al., (1994); Dhyani et al. (1995).

Selection of suitable species, selection of appropriate technology, sufficient inputs and effective organization etc. should be kept in mind during the initiation of ago-forestry programme minimizing the land degradation. Research is needed in specific land degradation situation to generate appropriate technologies. For reclamation of saline soils plant species which can withstand high salt content and thrive under high water table conditions should be selected for planting. Gill and Abrol (Gill and Abrol, 1986) and Grewal and Abrol (1986) in a study from Karnal India reported that Acacia nilotica and Eucalyptus terticornis can lower the soil pH from 10.5 to 9.5 in five years and lower electrical conductivity from 4 to 2 with

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tree establishment assisted by addition of gypsum and manure. For acidic soils Dhyani et al. (Dhyani et al., 1995) suggested plantation of Alnus nepalensis, Parkia javanica, Parkia facataria, Michelia oblonga and Melenia arborea, as these trees are highly adapted to acidity of soil (Table 4). The tree species like Prosopis jiliflora, Acacia nilotica, Casuarina equisetifolia, Tamarix articulata, Achras japota etc. can tolerate more than pH 10.0 and these trees are recommended for reclamation of alkali soils. Local communities play major role in reclamation and rehabilitation of degraded lands in both developed and developing countries. Alkali / sodic soil contain excess soluble salts which interferes the crop plants growth as they are capable of alkaline hydrolysis. Some trees like Prosopis juliflora, Acacia nilotica, Casuarina equisetiolie, Tamarix articulata, Achras japota etc are capable of tolerating pH more than that of 10 (Dagar et al., 1994; Hasan and Alam, 2006) (Table 4). Trees such as Terminalia arjuna, Salvadora persica, Cordia rothii, Eucalyptus terecornis, Zizyphus mauritiana, Emblica officinalis, Phoenix dactylifera, Tamarindus indica, Syzygium cumuni etc can tolerate pH 9.1 – 10.0. However, Azadirachta indica, Melia azaderach, Moringa oleifera, Vitis vinifera, Butea monosperma, Ficus sp. etc. can tolerate up to pH 9.0 (Dagar et al., 1994; Hasan and Alam, 2006) (Table 4). According to Nair (1993), as perennial woody vegetation are capable of recycling nutrients, maintaining soil organic matter and protecting the soil from surface, erosion, and runoff, agroforestry systems are the appropriate management of acid soils. Tree species like Alnus nepalensis, Parkia javanica, Parkia facataria, Michelia oblonga, Melenia arborea etc.are highly adapted to acidic soil, whereas Acacia auriculiformis, Michelia alba, Michelia lenigata etc. and less adapted eg. Leucaena leucocephala, Robinea pseudoacacia, Cryptomeria japonica, Cryptomeria torulosa, Pinus kesiya etc. are moderately adopted (Dhyani et al., 1995). The involvement of local communities and their knowledge of tree characteristic is the essential element of restoration success. The restoration programs provide a number of ecosystem services with high value for supporting human livelihoods viz. carbon storage, regulation of climate and water flow, provision of clean water, and maintenance of soil fertility (MEA, 2005; Chan and Shaw, 2006).

b. Reclamation of Degraded Land through Bioenergy Plantation Bioenergy plantation is increasing attention around the world since it might offer new opportunities for sustainable development, but on the other hand it also carries significant risks. The rise of commodity prices, the negative impact on food security and climate change represent different challenges to be overcome before the full potentials of bioenergy can be realized. In the context of the development of bioenergy, issues relating to agriculture need special attention. Bioenergy development is always linked with food security. Farmers, having the choice to convert their food crops to fuel crops, naturally expect a high return from their farmland, thereby generating a scenario where food production falls. Bioenergy is one of the most important potential sources of sustainable rural development for developing countries. If bio-energy plantation is combined with restoration and reclamation processes it provides benefits related to secure and economically viable energy supply, climate and soil protection and social development and equity. The most of the bioenergy plants like

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Jatropha, Simmondsia chinesis, Pongamia pinnata, Moringa oleifera, Madhuca indica, Ricinus communis, Citrullus colocynthis etc. have an advantage especially where soil quality is poor and barely sustains other crops. Kumar et al. (2008) showed that Jatropha can be easily grown on heavy metal contaminated soil by adding dairy sludge and biofertilizer to soil. The reclamation of such soil can be done by using bioenergy plantation as the outputs of these systems do not enter into human food chain. These bio-energy plantations can flourish on poor soils in arid or semi-arid environments and are able to withstand long droughts and build pavement to restoration of degraded ecosystems particularly in arid and semi arid regions. It is reported that bioenergy plantation like Jatropha is suitable for reclaiming marginal land were crop cultivation is not possible and convert it into arable land. However, the oil seed production under marginal conditions is not yet validated (Gabus and Hawthrone, 2008). Establishing large-scale biofuel plantations on these lands is promoted as a potentially sustainable alternative to conventional energy crops on productive arable lands (Jongschaap et al., 2007). Three different types of production systems are of most interest: the first comprises the cultivation of oil-bearing plants, to be used for the generation of biodiesel, a first-generation biofuel. Relevant crop species are Jatropha (Jatropha curcas L.), Castor (Ricinus communis L.), Pongamia (Pongamia pinnata) and oil palms (Elaeis sp.) (Achten et al., 2008; Wicke et al., 2008; Sharma et al., 2008). The second, crop mixtures of perennial grasses (Tilman et al., 2006), short-rotation woody crops (sartori et al., 2007), forest plantations (Jongschaap et al., 2007 ), and agroforestry systems (Grunewald et al., 2007 may be established on degraded lands as feedstock for the production of second-generation biofuels, e.g. (ligno)cellulosic ethanol (besides more conventional food, fodder and timber uses). The third, production system of most interest features crop species with novel traits which may be developed using modern plant breeding technology; for example, high-yielding, N-fixing warm season grasses with improved biomass quality might be used as substrates for designer fuel production (Schroder et al., 2008). In China, 23 million ha of marginal land are designated for biofuel production Tilman et al., 2006). About 75% of the world’s drier lands (45,000,000 km2) are affected by desertification, and every year 6,000,000 hectares of agricultural land are lost and converted to virtual desert. The United Nations Environment Programme has estimated that 4.5 billion dollars will be needed to be spent every year for the next twenty years to prevent the process of desertification. The main cause of desertification is the removal of vegetation, which in turn leads to unprotected, dry soil surfaces, which may blow away with the wind or are washed away by flash floods, leaving infertile lower soil layers that bake in the sun and become an unproductive hardpan. However, the other factors that can trigger desertification are the overgrazing, cultivation in marginal lands (i.e. lands on which there is a high risk of crop failure and a very low economic return), growing populations that increase pressure on fragile land resources and inappropriate agricultural technologies.

4. BENEFICIAL EFFECTS OF FORESTRY PRACTICES Forestry practices are the best possible way for the reclamation of degraded lands worldwide through improving the quality of forests and re-green degraded land provides

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much scope for carbon sequestration. Such afforestation programmes are also advantageous to arrest soil degradation, to improve soil fertility, to provide renewable fuel timber and nontimber forest products as well as to provide livelihood to millions of poor people worldwide. According to Canadell et al. (2007), the anthropogenic emissions due to fossil fuel combustion and cement manufacture are estimated at ~ 30 Pg C between 1850 and 2006, and an additional 158 Pg from land use change and soil cultivation. Additionally, the emissions due to fossil fuel combustion have increased from 7.0 Pg yr-1 in 2000 to 8.4 Pg yr-1 in 2006 Canadell et al. (2007). The concentration of atmospheric CO2 in 2006 of 381 ppm is the highest since several million years Canadell et al. (2007). Total emissions due to anthropogenic activity are estimated to be 7.0 Pg C yr-1 for 1970-1999, 8.0 Pg C yr-1 for 1990-1999, and 9.1 Pg C yr-1 for 2000-2006. For the aforesaid periods, the atmosphere has absorbed 3.1 Pg/yr, 3.2 Pg yr-1 and 4.1 Pg/yr, respectively. The capacity of the natural sinks (e.g., land, ocean) was 56.3%, 60.0% and 54.9% for 1970-1999, 1990-1999 and 2000-2006 periods, respectively. The capacity of land sink alone for the same period was 28.1%, 27.2% and 24.2%, respectively. Thus, the progressively decline in capacity of land as sink has been reported this is probably because of an increase in the extent and severity of desertification and degradation of world soils and ecosystems Canadell et al. (2007). There is a close relationship between global warming and desertification process. The process of desertification is likely to be exacerbated by the current and projected global warming. It has been estimated that land-use change in developing countries could contribute to global emissions to the extent of about 1.6 billion tonnes of carbon (Parikh and Kirit, 2002). Money spent by various agencies which account to be about Rs.50 billion (US$1.25 billion) per year on degraded land development is shown in Table 3. If all the efforts at afforestation were to succeed, India's net emissions of CO2 could come down significantly. Improving the soil quality with the help of resorting degraded soils has the important benefit of achieving food security by improving agronomic/biomass production and increasing use efficiency of input (e.g., fertilizers, irrigation, and energy). Lal (2006) estimated that by increasing soil organic C pool in degraded/desertified soils 1 Mg C ha-1 yr-1, global food production can increase by 2630 million Mg yr-1. Significant employment opportunities is generated by afforestation activities on degraded land, as 70–80% of the expenditure incurred on plantations is constituted in form of wages to laborers (Balooni and Singh, 2003).

CONCLUSION At present scenario, degradation of land is a global concern for agricultural and ecosystem productivity. However, the worse thing is that, the problem is rising in a quick succession, affect more in the future. So, it is the demand of time to check the further degradation and restore the degraded land. For an example, if we look at the state wise distribution of land area and percentage of degraded lands in India (Figure 2); it will be quite easy to understand that, irrespective of its nature, the land is degrading in a constant phenomenon. Diverse governmental and non-governmental organizations are spending huge money for the restoration of these degraded lands worldwide. Thus it was quite clear that, only sustainable practices; like – agro-forestry, forestry development, etc.; appear to have the potential to control erosion, improve soil fertility, and so lead towards best possible land use.

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Agroforestry is being treated as a component of sustainable agriculture in numerous countries. Research is required in specific land degradation situation to generate appropriate technologies. Planning of agroforestry is to be framed out at the top level. Linkage with international organizations should also be developed. Selection of suitable species, selection of appropriate technology, sufficient inputs and effective organization etc. should always be kept in mind during the initiation of agoforestry programme minimizing the land degradation. It is also quite important to conclude here that, land degradation is not a single and isolated problem. However, it depends on multiple factors, and on the other hand it affects multiple factors, which controls the survival of livelihood (Figure 3). So, this is the right time for us to move forward and make this world a better place for or next generation.

ACKNOWLEDGMENTS Authors are thankful to Banaras Hindu University, Varanasi, India for providing necessary help.

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REFERENCES Achten, W.M.J., Verchot, L., Franken, Y.J., Mathijs, E., Singh, V.P., Aerts, R. and Muys, B. (2008). Jatropha bio-diesel production and use (a literature review). Biomass Bioenergy 32, 1063-1084. Asner, G.P., Townsend, A.R., Bustamante, M.M.C., Nardoto, G.B. and Olander, L.P. (2004). Pasture degradation in the central Amazon: linking changes in carbon and nutrient cycling with remote sensing. Global Change Biology, 10(5), 844-862. Bai, Z.G., Dent, D.L., Olsson, L. and Schaepman, M.E. (2008). Global assessment of land degradation and improvement. Report 2008/01, ISRIC – World Soil Information, Wageningen. Balooni K. and Singh, K. (2007). Prospects and problems of Afforestration of wastelands in India: A synthesis of macro and microperspectives. Geoforum, 38, 1276 -1289. Balooni, K. and Singh, K. (2003). Financing of wasteland afforestation in India. National Resource Forum 27, 235-246. BARC (1999). Land degradation situation of Bangladesh. Soil Science Division. Bangladesh Agricultural Research Council, Farmgate, Dhaka. Canadell, J.G., Quére, C. Le., Raupach, M.R., Field, C.B., Buitenhui, E.T., Ciais, P., Conway, T.J., Gillett, N.P., Houghton, R.A. and Marland, G. (2007).Contributions to Accelerating CO2 Growth from Economic Activity, Carbon Intensity and Efficiency of Natural Sinks. Available at: http://www.pnas.org/cgi/doi/10.1073/pnas.0702737104. Cannell, M.G.R. van Noordwijk, M. and Ong, C.K. (1996). The central agroforestry hypothesis: the tress must acquire resources that the crop would not otherwise acquire. Agroforestry System 34, 27-31. Chambers, R., Saxena, N.C., Shah, R. (1989). To the Hands of the Poor - Water and Trees. Oxford and IBH Publishing Company.

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Chan, K.M.A., Shaw, M.R., Cameron, D.R., Underwood, E.C. and Daily G.C. (2006). Conservation planning for ecosystem services. PLoS Biol 4, e379 (2006). Dagar, J.C., Singh, N.T. and Singh, G. (1993). Agroforestry system for sustainable land use, Oxford & IBH publishing Co. Pvt. Ltd., New Delhi, India. pp. 112. Dhyani, S. K., Singh, B.P., Chaulan, D.S. and Prasad, R.N. (1995). Agroforestry systems for degraded lands, Science publishers, Inc. 52 La Bombard Road, North Lebanon NH, U.S.A., p. 243. Dregne, H.E. and Chou, N. (1994). Global desertification dimensions and costs. In: Degradation and Restoration of Arid Lands, ed. H.E. Dregne. Lubbock: Texas Technical University. Dudal, R. (1982). Land degradation in a world perspective". Journal of Soil and Water conservation. 37, 245-249. Eswaran, H. and Kapur, S. (1997). Land Degradation - Newsletter of the International Task Force on Land Degradation 1, 2-3. Fitzpatrick, R.W. (2002). Regional Water and Soil Assessment for Managing Sustainable Agriculture in China and Australia, ACIAR Monograph No. 84, 119-129. Gabus, A. and Hawthorne, A. (2008). Biofuels from dedicated tropical plantation forests: it is time for detailed studies of the lignofuels options International Forestry Review 10, 563572. Garg, V.K. (1998). Interaction of tree crops with a sodic soil environment: potential for rehabilitation of degraded environments. Land Degradation and Development 9(1): 81 93. Gautam, N.C., Nagaraja, R. and Rao, D.P. (1992). Wasteland survey and mapping in India. Land and Soils. ed by T. N. Khoshoo and B L Deekshatulu. Har-Anand Publications, New Delhi, pp.197-219. Gibson, A.H., Dreyfus B.L. and Dommergues, Y.R. (1982). Microbiology of tropical soils and plant productivity. The Hague: Nijhoff: 37-73. Gill, H.S. and Abrol, I.P. (1986). Amelioration of soil by trees: A review of current concepts and practices, London: Commonwealth Science Council. pp. 43-56. Govindarajan, M., Rao, M.R., Mathuva, M.N. and Nair, R.K. (1996). Soil – water and root dynamics under hedgerow intercropping in semiarid Kenya. Agronomy Journal 88, 513520. Grewal, S.S. and Abrol, I.P. (1986). Agroforestry on alkali soils: effect on some management practices on initial growth, biomass accumulation and chemical composition of selected tree species. Agroforestry System 4, 221-232. Grünewald, H., Brandt, B.K.V., Schneider, B.U., Bens, O., Kendzia, G. and Hüttl, R.F. (2007). Ecological Engineering, 29, 319. Gupta, R.K. and Abrol, I.P. (1990). Salt affected soil: their reclamation and management for crop production. Advances in Soil Science, 11, 223-288. Hasan, M.K. and Alam, A.A.K.M. (2006). Land degradation situation in Bangladesh and role of agroforestry. Journal of Agriculture and Rural Development, 4, 19-25. Jongschaap, R.E.E., Corré, W.J., Bindraban P.S. and Brandenburg, W.A. (2007). Claims and Facts on Jatropha curcas L.; Global Jatropha curcas evaluation, breeding and propagation programme, Plant Research International B.V., Wageningen; Stichting Het Groene Woudt, Laren, the Netherlands.

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Khanduja, S.D., Chandra, V., Srivastava, G.S., Jain, R.K., Misra, P.N. and Garg, V.K. (1987). Amelioration of soil by trees. Commonwealth Science Council, The Commonwealth Secretariat, Marlborough House, Pall Mall, London, pp 54–61. Kidd C.V. and Pimental, D. (1992). Eds, Integrated Re- source Management: Agroforestry for Development, Academic Press, San Diego. Kiran, R. Kudesia, M. Rani, A. Pal (2002). Reclaiming degraded land in India through the cultivation of medicinal plants. Botanical Research Institute Bulletin 2, 174. Kumar, G.P., Yadav, S.K., Thawale, P.R., Singh, S.K. and Juwarkar, A.A. (2008). Growth of Jatropha curcas on heavy metal contaminated soil amended with industrial wastes and Azotobacter. A greenhouse study. Bioresource Technology 99, 2078-2082. Lal, R. (2006). Enhancing crop yields in the developing countries through restoration of the soil organic carbon pool in agricultural lands. Land Degradation and Development, 17, 197-209. Larue, T.A. and Patterson, T.G. (1981). How much nitrogen do legumes fix? Advances in Agronomy 34, 15-38. LRMP (1986). Forestry land use report Mimeograph. Forestry land use report Mimeograph, Topographical Survey Branch, Kathmandu. Mandal, D. and Ghosh, S.K. (2000). Precision farming: The emerging concept of agriculture for today and tomorrow. Current Science 79, 1644 -1647. Millennium Ecosystem Assessment (2005). Millennium Ecosystem Assessment, Ecosystems and Human Well-Being: Synthesis, Island Press, Washington, DC. Ministry of Environment and Forest (MoEF) (2009). Ministry of Environment & Forests, Paryavaran Bhavan, CGO Complex, Lodhi Road, New Delhi, India. MoEST (2008). Thematic assessment report on land degradation. Ministry of Environment, Science and Technology; Government of Nepal, Kathmandu, Nepal. Nagaraja, B.C. (2009). 2nd German-Indian Conference on Research for Sustainability, United Nations University, Bonn, 27-28 April, (2009). Naidu, R. and Rengasamy, P. (1993). Ion interactions and constraints to plant nutrients in Australian sodic soils. Australian Journal of Soil Research, 31, 801-819. Nair, P.K.R. (1993). An introduction to Agroforestry. Kluwer Academic Publishers, Dordrecht. Ong, C.K., Corlett, J.E., Singh R.P. and Black, C.R. (1991). Above and below ground interactions in agroforestry systems. Forest Ecology Management 45, 45-57. Parikh, J.K. and Kirit, P. (2002). Climate change: India’s Perceptions, Positions Policies and Possibilities. OECD. Pohit, S. (2009). Land Degradation and Trade Liberalization: An Indian Perspective. Available at SSRN: http://ssrn.com/abstract=1457666. Ramankutty, N. and Foley, J.A. (1999). Estimating historical changes in land –cover: North American cropland from 1700 to 1992. Global Biogeochemical Cycles, 13, 997 – 1027. Rao, M.R., Nair, P.K.R. and Ong, C.K. (1998). Biophysical interactions in tropical agroforestry systems. Agroforestry System, 38, 3-50. Sanchez, P.A. (1995). Science in agroforestry. Agroforestry System, 30, 5-55. Sartori, F., Lal, R., Ebinger, M. H. and Eaton, J.A. (2007). Agriculture Ecosystem and Environment, 122, 325. Schröder, P., Herzig, R., Bojinov, B., Ruttens, A., Nehnevajova, E., Stamatiadis, S., Memon, A., Vassilev, A., Caviezel, M. and Vangronsveld, J. (2008). Bioenergy to save the

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world—Producing novel energy plants for growth on abandoned land. Environmental Science and Pollution Research 15, 196-204. Sharma, S.K., Singh, G., Rao G.G. and Yaduvanshi, N.P.S. (2008). Biomass and Biodiesel for Energy Production from Salt-Affected Lands. Central Soil Salinity Research Institute (ICAR) Karnal 132 001, India. p 20. Singh D.P. and Hazra, C.R. (1995). Agroforestry systems for degraded lands, Science publishers, Inc. 52 La Bombard Road, North Lebanon NH 03766, U.S.A. pp. 61. Singh, P. (1994). Agroforestry System for Sustainable Land Use. Oxford & IBH publishing Co. Pvt. Ltd., New Delhi, India. pp. 4-20. Sumner, M.E. (1993). Sodic soils: new perspectives. Australian Journal of Soil Research 31, 683-750. Tilman, D., Hill, J. and Lehman, C. (2006). Carbon-negative biofuels from low-input highdiversity grassland biomass. Science 314, 1598-1600. Tripathi, K.P., Singh, B. (2005). The role of revegetation for rehabilitation of sodic soils in semiarid subtropical forest, India. Restoration Ecology, 13, 29-38. United Nations (1992). Earth Summit - Convention on Desertification. Proceedings of the United Nations Conference on Environment and Development (UNCED), Rio De Janeiro, Brazil, June, 3-14, 1992. United Nations (1997). Dryland degradation keeping hundreds of millions in poverty; Press Release: Secretariat of the United Nations Convention to Combat Desertification,Geneva, Switzerland. Van Noordwijk, M. and Purnomosidhi, P. (1995). Root architecture in relation to tree-soilcrop interaction and shoot pruning in agroforestry. Agroforestry System, 30, 161-173. Wicke, B., Dornburg, V., Junginger, M. and Faaij, A. (2008). Different palm oil production systems for energy purposes and their greenhouse gas implications. Biomass Bioenergy 32, 1322-1337. World Bank (1993). World Bank strategy for development of the forest sector in Asia. Wastelands News, 8, 6-16. Yadav, J.S.P. (2000). Advances in Land Resource Management for 21st Century. Soil Conservation Society of India, 253-264. Young, A. (1991). Agroforestry for Soil Conservation. CAB International, Wallingford, pp 276.

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In: Land Management Editor: Surendra Suthar

ISBN: 978-1-62081-421-5 © 2012 Nova Science Publishers, Inc.

Chapter 9

GREEN TECHNOLOGY TO ACCELERATE ECOSYSTEM DEVELOPMENT PROCESS ON LLMESTONE MINE DEGRADED LAND Anuj Kumar Singh* College of Forestry, Orissa University of Agriculture and Technology, Bhubaneswar, India

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ABSTRACT As far as mined land restoration is concerned, the green technology involves reestablishment of soil properties through connecting the broken link of soil-plant-microbes system. As it is a fact that natural recovery of soil properties of mined spoils is a slow process which may take many years or decades. This restored link of soil-plant-microbes system alters the soil conditions accelerates the natural regeneration process. Microbes play a vital role between soil and plant interaction mechanism. Gradually, a biological balance between above ground i.e. vegetation and below ground flora i.e. microbial population; is established. Synergistic effects of plantation, microbial inoculation, mulching and manuring results into an established nutrient cycle which leads to the development of a self sustained ecosystem on the mined degraded land.

1. INTRODUCTION Mining is a threat for environment, though it is inevitable. Due to mining, huge amount of overburden material is disposed off adjacent to quarry, which create heaps of waste materials technically called mine spoils. The mine spoils, literally dumps that result from excavation and dumping create stark hostile conditions for vegetatal growth and establishment. These dumps are most often conical in shape; however, depends on dumping designs followed by mining authorities. Mine spoils represent very rigorous conditions for both plant and microbial growth because of low organic matter content, low organic carbon, *

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unfavorable pH, either coarse texture or compacted structures. Mine overburden dumps are mostly inert materials highly deficient in basic soil nutrients. Moreover, the overburden is alkaline in nature, highly calcareous and very poor in nutritional and microbial status. As a result, the vegetation cover in and around limestone mine is greatly reduced. The revegetation of such degraded soil is difficult and time taking process. Regeneration through succession on such highly degraded sites is very slow and mostly results in a low diversity of plant communities and associated microbial populations. It is required to explore possibilities for application of different biological tools to restore soil properties up to possible extent and biologically rejuvenate the soil system for the development of a self sustained ecosystem. It is also essential to introduce functional population of beneficial microbes in overburden dumps for effective nutrient mobilization and ability of plants to withstand stressed conditions. This article discusses about implication of green technology inclusive of afforestation supplemented beneficial microbial inoculants and other effective approaches for restoration of limestone mined degraded land.

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2. MICROBES AND NUTRIENT CYCLE It is universally accepted that the microbes are beneficial in the activity of important functions performed in the ecosystem. Soil microbial biomass, living part of the soil organic matter, is an agent of transformation of organic matter and source of available nutrients. The effective groups of microbes belong to bacteria, fungi, and actinomycetes. Activities of soil microbes can change the soil environment much rapidly and provide key controlling influence on the rate at which nutrient cycling processes take place and play a very important role in the formation of macro aggregates. The potential of soil microorganisms has been recognized widely in improvement of soil quality, soil formation, aggregation and revegetation through their activities in litter decomposition and nutrient cycling. Microbial activities such as phosphate solubilization, nitrogen fixation, oxidation of various inorganic components of soil or mineralization of inorganic components and mycorrhizal symbiosis are major beneficial activities that play a very important role in soil system functioning. Soil microorganisms inhabiting the rhizosphere environment interact with plant roots and mediate nutrient availability to the plants. Implications of plants and their symbionts like mycorrhizal fungi, N-fixing bacteria and free-living rhizosphere population of bacteria promote plants establishment and growth. In addition to their effects on soil fertility, they also enhance soil structure by binding together soil particles. An active soil microbial biomass is an essential factor in the long-term fertility of soils. Microorganisms improve the nutrient status and texture by addition of organic matter Palaniappan and Natrajan (1993). They also significantly contribute in improving status of soil nitrogen. Free living or symbiotic nitrogen fixers improve the nitrogen status with micronutrients and growth promoters. Microorganisms alter the pH of the habitat making it suitable for the establishment of higher plants. Some of the microorganisms are being applied as biofertilizers and have proved promising agent for the recovery of wastelands. The humic and fulvic acid fractions of humus are known to chelate micronutrients like copper, iron, zinc and manganese and also exert buffering action (Relan et al., 1986).

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Carbon fluxes are crucial determinants of rhizosphere function (Toal et al., 2000). The release of root exudates and decaying plant material provide sources of carbon compound for the heterotrophic soil biota as either growth substrates or structural material for root associated microbiota (Werner, 1998). Microbial activity in the rhizosphere affects rooting patterns and the supply of available nutrients to plants thereby modifying the quality and quantity of root exudates (Barea, 2000).Nitrogen-fixing microbes can exist as free-living organisms in associations of different degrees of complexity with other microbes and plants. The most abundant elements in the atmosphere (N2) are very often the limiting element for the growth of most organisms. Many soil organisms interact with each other to overcome of the limitations. Positive effects of Rhizobium sp. inoculation in combination with Azotobacter sp. or Azospirillum sp. inoculants have been reported for different forage and grain legumes. The role of microorganisms in nutrient cycling is unique. An active microbial biomass is an essential factor in the long-term fertility of soil. It is therefore essential that microbes beneficial for plant growth have to be introduced to the mined over spoils. Among the different microbes vesicular- arbuscular mycorrhizal fungi, nitrogen fixers and phosphate solubilizers are very important for any plant in nutrient deficient soil substrates. Phosphorus is an important plant nutrient next to nitrogen. The most important aspect of phosphorus cycle is microbial mineralization, solubilization and immobilization besides chemical fixation of phosphorus in the soil. Phosphorus solubilising microorganisms convert insoluble inorganic phosphate compounds into soluble form. A considerable higher concentration of phosphate solubilising bacteria is commonly found in the rhizosphere soil. Also the fungal genera with this capacity are Penicillium and Aspergillus (Whitelaw et al. 1999). Pseudomonas is a typical PGPR and their interactions with AM fungi mutually enhance each other’s colonization and achieve additive plant growth enhancement (Singh and Jamaludin, 2008). Another mechanism of action of PGPR on plant growth is the production of siderophores. The siderophores are produced by most fungi and bacteria including Pseudomonas, Rhizobium and Azotobacter (Meyer and Linderman, 1986).Arbuscular mycorrhizal fungi (AMF) which are an important group of soil-borne microorganisms; contribute substantially to the establishment, productivity, and longevity of natural or man-made ecosystems. These fungi form symbiotic association with most terrestrial plant families. Due to the extensive network of external hyphae which function as plant rootlets and increase phosphorus uptake. The species of Pseudomonas, Bacillus, Aspergillus, Penicillium etc. have been reported to be active in the bioconversion of insoluble phosphorus. These organisms produce organic acids like citric, glutamic, succinic, lactic and tartaric acids which are responsible for solubilization of insoluble forms of phosphorus. Phosphorus solubilising microorganisms synergistically interact with N-fixing microorganisms. Taking this fact into cognizance, the phosphorus solubilising microorganisms are being exploited as biofertilizers in agriculture, horticulture, forestry and agro-forestry (Gaur, 1990).

3. MYCORRHIZAL TECHNOLOGY IN LAND RESTORATION Arbuscular Mycorrhizal associations are important in natural and managed ecosystems due to their nutritional and non- nutritional benefits to their symbiotic partners. They can alter plant productivity because AMF acts as biofertilizers, bioprotectant or biodegraders and are

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known to improve plant growth and health by improving mineral nutrition or increasing resistance or tolerance to biotic and abiotic stresses. Mycorrhizal fungi are species of fungi that intimately associate with plant roots forming a symbiotic relationship, with the plant providing ca for the carbohydrate for fungi and the fungi providing nutrients such as phosphorus, to the plants. Mycorrhizal fungi can absorb, accumulate and transport large quantities of phosphate within their hyphae and release to plant cells in root tissue. Mycorrhizal symbiosis is very important in agriculture and forestry. Plants inoculated with arbuscular mycorrhiza have been shown to be more resistant to some root diseases. It is now generally recognized that they improve not only the phosphorus nutrition of the host plant but also its growth, which may rest in an increase in resistance to drought stress and some diseases. Therefore, AM fungi offer a great potential for sustainable agriculture, and the application of AM fungi to agriculture has been developed.

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4. RESTORATION PROCESS To the extent possible, mine spoils need to be leveled or terraced in order to provide suitable substratum. Leveling will vary according to the type of mine, methods of mining and the way in which a particular area has been worked. For instance, in case of surface and opencast mines the procedures will be leveling and fencing of the area. In case of shaft and underground mines although overburden can be treated in similar fashion but mined out areas and abandoned mines will have to have different strategy depending upon the context. Mined out areas in hillside slopes may require contour dikes. Leveling will provide a base of coarse material over which to spread sediment. The main physical problems with mine spoils are shallow substrate of soil (or often lack of it), large cavities in the very coarse-grained substrate, very high stone content, extremely coarse texture, compaction, and the limited availability of moisture. Excavated sediment of ponds and tanks is an effective indigenous soil amendment practice in India. Pond silt is not only productive but also a seed bank for a variety of grasses, herbs, shrubs, and trees (Pandey et al., 2005). This silt, rich in organic material, can be used for preparation of topsoil layer of about 30-50 cm over the mine waste and leveled pits. The silt layer increases the productivity of the land and also helps in ground water recharge. Transporting the silt away from ponds and using it for organic enrichment of mine spoil serves other purposes as well including the safe disposal of excavated sediment and solid waste, ecological restoration of mine-waste, and increased rainwater storage capacity for local people. In addition to the above activity, in situ moisture conservation to encourage growth of vegetation over mine spoils could be useful. For example, rehabilitation success to revegetate mine spoils in arid regions in India was achieved using a combination of in situ rainwater harvesting, soil amendments, and establishment of trees, shrubs and grasses (Sharma et al., 2001). The process of ecological restoration of mined spoils may be described under following sub-processes:

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(I) Restoration of Soil Characteristics Soil acts as a critical controlling component in the development of ecosystem. Mine spoils are not suitable for both plant and microbial growth because of low organic matter content, unfavorable pH, and drought arising from coarse texture or oxygen deficiency due to compaction. The other limiting factors for re-vegetation of mine spoil may be salinity, alkalinity, poor water holding capacity, inadequate supply of plant nutrients and accelerated rate of erosion. During the reclamation of mine spoil, it is often necessary to establish and maintain a vegetative cover without the use of top soils or other bulky amendments (Rimmer, 1982). The cycling of nutrients regulates the sustainability of any plant community. Without cycling, nutrients will be lost or immobilized and the plant community will not be capable of regeneration. Reeder and Berg (1977) suggested that rapid re-establishment of the nitrogen cycle appears to be particularly important, but often difficult to achieve in mine spoil. In mine spoils, geomorphic system is in disequilibrium due to the destruction between landform and processes, which accelerates erosion rate. Destruction of soil properties causes reduced soil productivity. Natural plant succession is also very slow on mine spoils. Establishment of plantations may accelerate this process leading to a self sustained ecosystem in a relatively short period of time (Singh and Singh, 1999). Plantations impart a favorable role in the biological reclamation of mine spoil due to modification of the soil characteristics. Restoring fertility to land that has been ravaged by mining poses serious scientific challenges warranting extensive research on many fronts. The application of native microbial population which is will adapted, stress tolerant and plantation of fast growing tree species amended with mulching treatments may ensure primary goal of re-establishment of the soil’s natural biogeochemical cycles. Such progress, in turn, would allow the natural invasion of multiple herbs, shrubs and tree species that would not only help in soil stabilization but would enhance the soil's physico-chemical and nutritive properties. In addition, integrating such biofertilizers as Rhizobium, Azospirillum and arbuscular mycorrhizal fungi on to the saplings would enable the plant species to become more tolerant to stress by ensuring continuous supplies of nutrients during their early stages of growth. In most situations, biofertilizers would likely be more effective than traditional chemical fertilizers. Moreover, their use would minimize problems associated with toxic runoff because the levels of chemicals applied to the soil would be significantly reduced. The strategy has proven successful; the use of biofertilizers has both reversed the damage and subsequently enhanced the nutritive capacity of soils without causing environmental damage.

(II) Ecosystem Approach for Mined Land Restoration A number of restoration ecologists have suggested many approaches for rehabilitation of mined land, however the approach adopted by Soni and co-workers (1992) is highly suitable for calcareous mines restoration in Indian context. The major aims of ecorestoration and rehabilitation of mined spoils should be 

Speedy development of vegetal cover capable of reducing soil erosion.

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To provide ecological site stability in terms of favorable soil environment to support colonization of diverse flora and fauna. Enrichment of soil nutrient levels, weathering of overburden materials and humification of organic matter. Biorejuvenation of soil system. Growth and survival of above ground and belowground flora. Creation of self sustained ecosystem

(III) Activities under Ecosystem Approach of Rehabilitation I.

Studies on mined lands, overburden dumps and spoils a) Ecological survey of major vegetative association and natural succession. b) Characterization of mine spoils and identification of limiting elements for plant growth. II. Stabilization of sites through mechanical measures. III. Selection of site specific suitable plant species. IV. Planting technique. V. Use of amendments – Application of biofertilizers, mulching and manuring. VI. Moisture retention and water harvesting. VII. Protection, Monitoring and Evaluation.

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(IV) Selection of Site-specific Suitable Plant Species For sustainability of the ecosystem, selection of most suitable species is important. The basis of species selection is:     

Indigenous species of the particular eco-climatic or agro-climatic zone Capable of colonizing degraded areas Fixing atmospheric N2 as well as conserving soil Capable of attracting avian fauna Fast growing species should be given preference

5. BIO- INOCULANTS IN SOIL RESTORATION The soils of disturbed sites are frequently low in available nutrients and lack the nitrogenfixing bacteria and mycorrhizal fungi usually associated with root rhizospheres. As such, land restoration in semi-arid areas faces a number of constrains related to soil degradation and water shortage. As mycorrhizae may enhance the ability of the plant to cope with water stress situations associated to nutrient deficiency and drought, mycorrhizal inoculation with suitable fungi has been proposed as a promising tool for improving restoration success in semi-arid degraded areas (Pigott, 1982). By stimulating the development of beneficial microorganisms in the rhizosphere, the use of VAM-infected plants could reduce the amount of fertilizer

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needed for the establishment of vegetation and could also increase the rate at which the desired vegetation becomes established by stimulating the development of beneficial microorganisms in the rhizosphere. Degraded soils are common targets of revegetation efforts in the tropics, but they often exhibit low densities of AMF fungi (Michelsen and Rosendhal, 1990). This may limit the degree of mycorrhizal colonization in transplanted seedlings and consequently hamper their seedling establishment and growth in those areas. Soil inoculation with G. mosseae has significantly enhanced plant growth and biomass production in limestone mine spoils. Inoculation of native and well adapted microbial flora may prove a proficient tool for restoration of heavily degraded limestone mine spoils. Native beneficial microbial flora like arbuscular mycorrhizal fungi along with Phosphorus solubilising bacteria (PSB) and nitrogen fixing bacteria inoculated in different important plant species viz. Pongamia pinnata [Figure 1], Jatropha curcas and Ailanthus excelsa [Figure 2] had resulted into enhanced growth of inoculated plants as compared to uninoculated one. Moreover, inoculation with beneficial plant growth promoting rhizobacteria (PGPRs) changed the soil characteristics and also allowed increased invasion and natural succession on planted spoil as compared to unplanted sites (Singh and Jamaluddin, 2009). Similar results on enhanced growth of planted species with inoculation of G. mosseae in limestone mine spoils were also reported by Rao and Tak (2002).The benefits of optimization (via inoculation ) of AMF in production systems with low indigenous inoculum or efficacy have included:

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      

Increased plant nutrient uptake via the AM fungus mostly phosphorus Increased tolerance against certain pathogens by the plant system Increased tolerance drought condition and adverse environmental conditions (e.g. heavy metal pollutants) Increased efficacy of N-fixation by Rhizobium and other nitrogen fixing bacteria Accelerated natural regeneration Enhanced plant diversity in restored ecosystems Increased stability of soils

6. MULCHING AND MANURING Mulch is any material that is used to cover the soil for beneficial purposes. Plants growing in the forest are naturally mulched with a layer of fallen leaves, flowers, fruits, and branches. Mulch protects roots from drying and temperature extremes, and it enhances the soil conditions that improve plant growth and health. Mulch helps reduce competition from grasses and weeds around the base of plants; resulting in improved growth, especially during establishment of new plantings. Grasses and weeds compete for water and nutrients, and some release chemicals that injure other plants. Research indicates that allowing turf to grow over tree root zones reduces tree growth. Mulch also can protect plants from possible injury from herbicide applied to surrounding turf. Mulches improve the quality of the soil in the root zone by improving soil structure, especially by increasing porosity. When soil is porous, water easily enters and percolates through it. With good porosity, more water is absorbed and held in the soil, but drainage is also improved. Mulch protects the soil surface from becoming sealed by the impact of raindrops, keeping it “open.” Mulch acts as a vapor barrier to prevent

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rapid evaporation of water from the soil, which is especially useful in areas prone to drought. Because mulching can improve water absorption and retention in the soil, irrigation water can be conserved and maintenance time can be reduced. Organic mulches, as they decompose, contribute to the soil organic matter content. Organic matter improves soil structure and porosity by promoting soil aggregation. With improved soil structure, erosion and cracking which breaks plant roots are reduced. Soil organic matter also contains plant nutrients and provides food for beneficial soil microorganisms.

Figure 1. Pongamia pinnata treated with microbial inoculants and planted on limestone mine spoil.

Organic mulches are derived from living sources. The best ones are woody, fibrous waste materials that will degrade slowly and are in large enough pieces to allow for good air circulation. Mulches are usually graded by size: fine, medium, or coarse. Medium and coarse grades of organic mulch are excellent for use around plants. Suitable materials include shredded bark and coconut husks, wood chips, and macadamia husks; these materials may be partially composted before use. Coarse mulches will stay in place and don’t easily blow or wash away. Fresh wood chips, such as those that are available from tree-trimming companies, can be used effectively. Fine sawdust or freshly ground bark are less desirable than coarse materials because they have a lot of surface area for their volume, causing them to react with the soil, break down rapidly, and take nitrogen from the soil as they decompose. Fine materials require frequent replacement. They also can pack and form a barrier to air and water entering the root zone. The smaller particles blow or float away easily when dry. When mulching with fine or fresh materials, nitrogen fertilizer should be added to the mulch after

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application. Compost is organic material that has been allowed to decompose. Mature compost, unlike most mulch materials, is decomposed to the point where its components are no longer recognizable. Although mature compost has medium-fine texture, it will not tie up soil nitrogen like fine or fresh materials do. Mulching requires fairly large amounts of material, however, and mature compost may be better used mixed into the soil as a soil amendment. A wide variety of materials are effective as mulches. Some researchers (Armiger et al., 1976) recommended the use of pulp fiber, straw, sawdust, woodchips, hay, gravels and some chemicals as mulching materials. Selection of mulching material depends on availability and proximity to the area to be treated. Addition of organic wastes has been found to increase nitrogen fertility at a surface coal mine reclamation site, which ultimately stimulated microbial activity and improved the physical and chemical properties of the reclaimed soil. Mulching amendments can change the microclimate of the rhizosphere spoil. Mulches protect the site by reducing the impact of raindrops, soil erosion, water runoff and increasing water infiltration into the soil. Mulching treatments have been reported effective in lowering the soil temperature in the rhizosphere (Prihar et al., 1979). Moreover, organic mulches after decomposition can improve the fertility status of the spoils and help in growth and development of plants in disturbed sites.

Figure 2. Jatropha curcas and Ailanthus excelsa planted on limestone mine spoil.

7. PLANTATION ACTS AS CATALYST Numerous studies have demonstrated that land rehabilitation benefits from plantations because it allows jump start succession. The catalytic effects of plantations are due to favorable microclimatic conditions, rhizosphere environment and microbial status (increased soil moisture, reduced temperature, mineralization of nutrients due to increased microbial activities etc.), increased vegetational structure complexity, development of litter and humus layers and the soil physical and chemical environment and accelerating development of diversity on degraded sites. Plantations have an important role in protecting the soil surface

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from erosion and altering the accumulation of fine particles. Plantation can reverse degradation process by stabilizing soil mass through development of extensive root systems. The process of biological rejuvenation of mine spoil and mine land productivity and fertility through amendment of biofertilizers can enhance ground water recharge and enable restoration of the degraded land ecosystem (Juwarkar et al., 2004).Plantation of suitable species speed up succession that fulfills revegetation goal. Besides controlling leaching of nutrients through soil erosion increases plant diversity. Mine spoils can be stabilized through the establishment of plant cover. Earlier studies indicated that well adapted plant species could be recommended to establish self-sustaining cover, which require little maintenance activities (Redente et al., 1984). In restoration, emphasis is given first to build soil organic matter, nutrients and vegetation cover to accelerate natural recovery process. Plantation can be used as a tool for mine spoil restoration as they have ability to restore soil fertility and ameliorate microclimatic conditions. Trees can potentially improve soil through numerous processes, including maintenance or increase of soil organic matter, biological nitrogen fixation, uptake of nutrients from below the reach of roots of under story herbaceous vegetation, increase water infiltration and storage, reduce loss of nutrients by erosion and leaching, improve soil physical properties and soil biological activity (Singh and Vasistha, 2004). An important goal of restoration is to accelerate natural successional processes so as to increase biological productivity, reduce rates of soil erosion, increase soil fertility and increase biotic control over biogeochemical fluxes within the recovering ecosystems. Analysis of different natural successions on natural and artificial substrates suggests that one of the important factors limiting the rate of development is the process of immigration of flora. There are genuine difficulties in appropriate species reaching a particular site. Artificial re-vegetation is often used to facilitate the generally slow natural rehabilitation process. Plantations have an important role in protecting the soil surface from erosion and allowing the accumulation of fine particles. Once they are established, plants increase soil organic matter, lower soil bulk density, and moderate soil pH and bring mineral nutrients to the surface and accumulate them in available form. Their root systems allow them to act as scavengers of nutrients which are not readily available. The plants accumulate these nutrients and re-deposit them on the soil surface in organic matter, from which nutrients are much more readily available for microbial breakdown. Most importantly, some species can fix and accumulate nitrogen rapidly in sufficient quantities to provide a nitrogen capital. Once the soil characteristics have been restored, it is not difficult to restore a full suit of plant species to form the required vegetation.

CONCLUSION Green technology, in rehabilitation of mined land, involves application of biological tools like planting of suitable tree species, inoculation of beneficial microbial flora, application of mulches and manures. These biological tools acts synergistically and alter soil characteristics which lead to the development of favorable micro-climate of soil. A nutrient cycle is established, resulting into immigration of native flora which results into natural regeneration on mined spoils, and ultimately a self sustained ecosystem is developed.

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REFERENCES Armiger, W.H., Jones jr, J.N. and Bennett, O.L. (1976). Revegetation of land disturbed by strip mining in Appalachia. ARS-NE-71,USDA,Washington, DC, 38pp. Barea, J.M. (2000). Rhizosphere and Mycorrhizae of field crops, In Biological Resource Management, connecting science and Policy(OECD),Toutant, P., Balazs, E., Galante, E. (eds.), INRA and Springer, Berlin, Heidelberg, New York. Gaur, A.C. (1990). Phosphate solubilizing bacteria as biofertilizer,160-176:In Phosphate solubilizing microorganisms as biofertilizers. Omega Scientific Publishers, New Delhi. Juwarkar, A.A., Jambulkar, H.P. and Singh S.K. (2004). Appropriate strategies for reclamation and revegetation of coal mine spoil dumps, In Proc. of National Seminar on Env. Engg. with special emphasis on Mining Environment, ISM, Dhanbad. Meyer, R.J. and Linderman, R.G. (1986). Response of subterranean clover to dual inoculation with vesicular arbuscular mycorrhizal fungi and plant growth promoting rhizobacterium Pseudomonas putida. Soil Biol.Biochem. 18 (2), 185-190. Michelsen A. and Rosendhal, S. (1990). The effect of VA mycorrhizal fungi,phosphorus and drought stress on the growth of Acacia nilotica and Leucaena leucocephala seedlings. Plant and Soil 133, 79-83. Palaniappan, S.P. and Natarajan (1993). Practical aspects of organic matter maintenance In soils.23-41:In Organics in soil health and crop production, Thompson, P.K. (eds.) Tree crops development foundation, India. Pandey, D.N., Chaubey, A.C., Gupta, A.K. and Harshavardhan. (2005). Mine spoil restoration: A strategy combining rainwater harvesting and adaptation to random recurrence of droughts in Rajasthan. Report: International Network on Ethno forestry, Jaipur, India, 19pp. Pigott, C. D. (1982). Survival of mycorrhizas formed by Centroccocum geophilum in dry soils. New Phytologist 92, 513-517. Prihar, S.S., Singh, N.T. and Sandhu, B.S. (1979). In Soil physical properties and crop production in the tropics, Lal. R. and Greenland, D.J.(eds.), 1979, John Wiley and sons, Great Britain. Rao A.V., Tak, R. (2002). Growth of different tree species and their nutrient uptake in limestone mine spoil as influenced by arbuscular mycorrhizal (AM)-fungi in Indian arid zone. Journal of Arid Environments 51(1), 113-119. Redente, E. F., Doerr, T.B., Grygiel, C.E. and Biondini, M.F. (1984).Vegetation establishment and succession on disturbed soils in Northwest Colorado. Reclamation and Revegetation Research 3, 153-165. Reeder, J.D.G. and Berg, W.A. (1977). Nitrogen mineralization and nitrification in a cretaceous shale and coal mine spoils. Soil Sci. Soc. America J. 41 (5), 922-927. Relan, P.S., Tekchand, S.S., and Kumari, R. (1986). Stability constraints of Cu, Pb, Zn, Fe and cadmium complexes with humic acids from manure. J. Indian Soc. Soil. Sci. 34, 250. Rimmer, D.L. (1982). Soil physical conditions on reclaimed colliery spoil heaps. J. Soil Science 33, 567-579. Sharma, K.D., Kumar, S. and Gough, L. (2001). Rehabilitation of Gypsum mined lands in the Indian desert. Arid Land Research and Management 15, 61-76.

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Singh, A. K. and Jamaluddin (2009). Effect of bio-inoculants and stone mulch on performance of biodiesel and medicinal plant species on limestone mined spoil. Mycorrhiza News 21(3), 31-33. Singh, A.K. and Jamaluddin. (2008). Phosphatase activity in the rhizosphere of medicinal plants inoculated with Arbuscular Mycorrhizal Fungi. Mycorrhiza News 19(3), 11-12. Singh, A.K. and Singh, R.B. (1999). Effect of mulches on nutrient uptake of Albizia procera and subsequent nutrient enrichment of coal mine overburden. J. Trop. For. Sci. 11(2), 345-355. Singh, D. and Vasistha, H.B. (2004). Rehabilitation of mined degraded lands in the Himalayas through silvi-pastoral models. Indian Forester, April, 398-404. Soni, P., Kumar, O. and Vasistha, H. B. (1992). Reclaiming mined lands for management of water quality. Indian Journal of Forestry 15(1), 9-16. Toal, M.E., Yeomans, C., Killham, K. and Meharg, A. (2000). A review of rhizosphere carbon flow modeling. Plant and Soil 222, 263-281. Werner, D. (1998). Organic signals between plants and micro-organisms, 197-222: In The Rhizosphere : Biochemistry and organic substances at the soil-plant interfaces, Pinton, R.,Varanini, Z. and Nannipieri, P.(eds.), New York, Marcel Dekker. Whitelaw, M.A., Harden, R.J. and Helyar, K.R. (1999). Phosphate solubilization in culture by the soil fungus Penicillium radicum. Advances in Agronomy 31, 655-665.

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ABOUT CONTRIBUTORS Dr. A. Bello-Dambatta, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, Devon, EX2 4ER, UK. Dr. Akbar A. Javadi, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, Devon, EX2 4ER, UK. Dr. J. S. Oestreicher, Institute of Environmental Sciences, Faculty of Science, UQAM (Université de Québec à Montréal), Montreal, Quebec H3C 3P8, Canada. Dr. Surendra S Suthar, School of Environment and Natural Resources, Doon University, Ajabpur, Dehradun-248001, Uttarakhand, India. Dr. Sushma Singh, Department of Chemistry, Nehru Memorial PG College, Hanumangarh Town-335513, Rajasthan, India. Dr. Pravin K Mutiyar, Environmental Engineering Unit, Department of Civil Engineering, Indian Institute of Technology (IIT), Hauz Khas, New Delhi-110012, India. Dr. P. Pramanik, Division of Applied Life Science (BK 21 Program), Gyeongsang National University, Jinju, 660-701, South Korea. Dr. G.K. Ghosh, Department of Soil Science and Agricultural Chemistry, Palli Siksha Bhavana, Institute of Agriculture, Visva-Bharati, Bolpur, India. Dr. G. Pangging, Department of Forestry, North Eastern Regional Institute of Science and Technology, Nirjuli 791109, Arunachal Pradesh, India. Dr. K. Arunachalam, School of Environment and Natural Resources, Doon University, Ajabpur, Dehradun-248001, Uttarakhand, India. Dr. A. Arunachalam, Division of Natural Resources Management, Indian Council of Agricultural Research, Pusa Road, New Delhi- 110012, India. Dr. Selma Beatriz Pena, Instituto Superior de Agronomia, Universidade Técnica de Lisboa (TULisbon), Tapada da Ajuda, P-1349-017 Lisboa, Portugal. Dr. Maria Manuela Abreu, Instituto Superior de Agronomia, Universidade Técnica de Lisboa (TULisbon), Tapada da Ajuda, P-1349-017 Lisboa, Portugal. Dr. Roberto Lindig-Cisneros, Centro de Investigaciones en Ecosistemas, Universidad Nacional Autonoma de Mexico, Campus Morelia, Antigua Carretera a Patzcuaro 8701, Morelia 58190, Michoacan, Mexico. Dr. Ian MacGregor-Fors, Centro de Investigaciones en Ecosistemas, Universidad Nacional Autonoma de Mexico, Campus Morelia, Antigua Carretera a Patzcuaro 8701, Morelia 58190, Michoacan, Mexico.

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Dr. Rubén Ortega-Álvarez, Centro de Investigaciones en Ecosistemas, Universidad Nacional Autonoma de Mexico, Campus Morelia, Antigua Carretera a Patzcuaro 8701, Morelia 58190, Michoacan, Mexico. Dr. Arnulfo Blanco-García, Centro de Investigaciones en Ecosistemas, Universidad Nacional Autonoma de Mexico, Campus Morelia, Antigua Carretera a Patzcuaro 8701, Morelia 58190, Michoacan, Mexico. Dr. Rajeev Pratap Singh, Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi-221005, India. Dr. Sonu Singh, Division of Environmental Sciences, Indian Agriculture Research Institute, Pusa, New Delhi 110 012, India. Dr. Anita Singh, Department of Botany, Allahabad University, Allahabad, India. Dr. Puneet Singh Chauhan Department of Agricultural Chemistry, Chungbuk National University, Chungbuk - 361-763 South Korea. Dr. Anuj Kumar Singh, College of Forestry, Orissa University of Agriculture and Technology, Bhubaneswar, India-751003.

INDEX # 20th century, 70, 81, 85

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A access, 24, 109, 110 accounting, 13, 26, 75 acetic acid, 64, 66 acetone, 64 acid, x, 50, 55, 56, 57, 58, 59, 61, 64, 65, 130, 137, 146 acidic, 48, 58, 130, 136, 137 acidity, 48, 125, 126, 137 AD, 41 adaptation, 155 adjustment, 27, 83 adsorption, 59 adverse conditions, 84 adverse effects, 10 aesthetic, 75 affirming, 35 Afghanistan, 133 Africa, 133 agar, 64 agencies, 6, 7, 131, 132, 133, 139 aggregation, 44, 53, 146, 152 Agricultural Research Service, 38 agricultural sector, 23 agriculture, ix, x, 24, 26, 35, 39, 41, 43, 44, 45, 47, 49, 50, 52, 53, 85, 86, 87, 88, 98, 103, 108, 119, 121, 128, 129, 133, 137, 140, 142, 147, 148 agro-forestry, x, 125, 139, 147 alkaline hydrolysis, 137 alkalinity, 125, 126, 149 alters, 145 aluminium, 56, 59 AMF, 147, 151

ammonia, 52 ammonium, 40, 47, 48, 53, 64, 65 animal husbandry, 41 animal welfare, 45, 52 appropriate technology, 41, 136, 140 aquifers, 2, 3, 20 arbuscular mycorrhizal fungi, 147, 149, 151, 155 arrest, 139 ARS, 155 articulation, 80, 105 aseptic, 64 Asia, 40, 42, 78, 133, 143 assessment, x, 13, 14, 16, 19, 25, 37, 70, 79, 80, 81, 82, 88, 89, 93, 105, 107, 109, 121, 140, 142 assessment tools, 70 assets, 128 atmosphere, 81, 135, 139, 147 atmospheric deposition, 2 attitudes, 4 authorities, 8, 145 authority, 8, 9 avian, 150 awareness, 4, 47 B bacteria, 46, 55, 56, 60, 63, 64, 65, 67, 87, 146, 147, 151, 155 Bangladesh, 133, 140, 141 banks, 99, 103 barriers, 119, 120 base, 40, 89, 148, 151 basic needs, 73, 76 bedding, 66 beneficial microbes, 146 beneficiaries, 24 benefits, 12, 13, 18, 24, 86, 116, 119, 134, 135, 137, 147, 151, 153

160

Index

benthic invertebrates, 118 Bhutan, 133 biochemical processes, 62 bioconversion, 147 biodiesel, 138, 156 biodiversity, x, 8, 39, 49, 69, 70, 74, 77, 86, 105, 114, 116, 119, 121, 126, 128, 129, 131 bioenergy, 41, 137 bio-energy plantation, x, 137 biofuel, 53, 138 biogas, 54 biological activity, 45, 154 biological processes, 105, 128, 129 biomass, x, 41, 51, 55, 56, 62, 67, 79, 82, 85, 86, 87, 90, 96, 101, 128, 129, 138, 139, 141, 143, 146, 147, 151 biosphere, 81 biotic, 148, 154 birds, 116, 118, 119, 120 Brazil, 25, 82, 143 breakdown, 154 breeding, 121, 138, 141 Britain, 20 buffalo, 42 Burma, 69 buyers, 24 by-products, 52

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C cadmium, 155 calcium, 40, 50, 64 calibration, 22, 26, 27, 28, 29, 30, 31, 32, 33, 36 candidates, 41 capacity building, 75 carbohydrate, 148 carbon, 2, 26, 48, 50, 53, 54, 55, 56, 57, 58, 62, 75, 77, 87, 128, 129, 135, 137, 139, 140, 142, 145, 147, 156 Caribbean, 28 case studies, 40, 105 case study, x, 110 cash, 74 catalytic effect, 153 cation, 128, 129 cattle, 21, 24, 34, 35, 36, 41, 42, 43, 49, 130 CCA, 22, 27 certificate, 116 certification, 70 challenges, 10, 12, 39, 119, 125, 126, 137, 149 charm, 37

chemical, ix, 2, 14, 17, 25, 39, 40, 41, 42, 43, 44, 47, 48, 49, 50, 51, 52, 54, 56, 57, 59, 83, 85, 87, 88, 117, 128, 129, 130, 134, 135, 141, 147, 149, 153 chemical characteristics, 43, 44 chemical degradation, 130 chemical properties, 49, 51, 52, 56, 117, 153 chemical-based farming system, ix, 40, 48, 52 chemicals, 3, 40, 47, 126, 129, 130, 131, 149, 151, 153 Chile, 121 China, 25, 38, 111, 138, 141 chitin, 67 chlorine, 40 chloroform, 64 circulation, 83, 152 citizens, 74 City, 36 civilization, 126 clarity, 120 classes, 70, 79, 90, 91, 93, 104, 105, 107 classification, 23, 26, 35, 90, 101 clay minerals, 87 cleaning, 4, 17, 18 cleanup, 9 climate, 2, 23, 24, 49, 87, 109, 125, 137, 154 climate change, 2, 24, 109, 125, 137 close relationships, 115 CO2, 43, 57, 62, 79, 82, 139, 140 coal, 153, 155, 156 colonization, 51, 147, 150, 151 combustion, 139 commercial, 24, 27, 42, 70 commercial crop, 27, 42 commodity, 137 communities, 12, 47, 50, 70, 72, 73, 76, 77, 78, 84, 114, 118, 137, 146 community, 41, 45, 70, 72, 75, 76, 77, 114, 115, 118, 120, 121, 122, 149 compaction, 66, 75, 86, 98, 100, 128, 129, 130, 148, 149 comparative advantage, 24 competition, 151 complement, 36 complexity, 13, 72, 147, 153 composition, 49, 117, 118, 121, 131, 141 compost, x, 39, 42, 45, 47, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 66, 67, 153 composting, 40, 41, 46, 51, 56 compounds, 45, 51, 56, 147 comprehension, 82 computer, 38 conceptual model, x, 13, 114 conditioning, 46

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Index conductivity, 43 Congress, 109 conifer, 116, 117, 118, 120, 121 connectivity, 110 conservation, ix, 11, 12, 21, 23, 24, 25, 34, 35, 36, 38, 44, 53, 69, 72, 74, 76, 78, 80, 82, 86, 87, 96, 103, 105, 107, 114, 119, 120, 121, 126, 129, 141, 148 conserving, 12, 24, 150 constituents, 85, 87 construction, 38, 85, 93 consumers, 25 consumption, 10, 12, 40, 42, 73, 75 contaminant, 7, 9, 10, 13, 14, 17 contaminated land policy, ix, 1, 5, 6, 11, 15 contaminated sites, 1, 4, 6, 7, 10, 11, 17, 19 contaminated soil, 3, 17, 138, 142 contamination, ix, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 16, 17, 18, 19, 20, 40, 126 continuous fertilization, x, 56 contour, 24, 45, 108, 148 cooperation, xi copper, 40, 146 copyright, 19 correlation, 61 correlations, 26 cost, x, 3, 4, 13, 17, 18, 25, 40, 45, 56, 114, 126, 133 Costa Rica, 25 Council of Europe, 80, 110 covering, 17, 45, 101 creep, 108 crises, 131 crop, x, 16, 24, 27, 39, 40, 41, 43, 44, 45, 47, 48, 49, 51, 53, 56, 73, 86, 108, 119, 126, 135, 137, 138, 140, 141, 142, 143, 155 crop production, 39, 41, 48, 86, 141, 155 crop residue, 39, 41, 43, 45, 47, 49, 53 crop rotations, 44, 45, 108 crops, 9, 35, 36, 38, 39, 40, 41, 45, 47, 50, 108, 126, 130, 134, 135, 137, 138, 141, 155 cultivation, ix, 23, 25, 26, 40, 41, 51, 74, 128, 129, 131, 138, 139, 142 cultural heritage, 8 cultural practices, 89 culture, 23, 25, 63, 64, 65, 156 culture medium, 64 cycles, 83, 86, 149 cycling, 67, 77, 87, 88, 140, 146, 147, 149 D data collection, 80, 88 data set, 33

161

database, 27 decay, 59 decision-making process, 13, 107 decomposition, 44, 56, 59, 67, 146, 153 defects, 9 defence, 2 deficiency, 59, 126, 149, 150 deficit, 21, 42 deforestation, 23, 25, 129 DEFRA, 2, 7, 8, 9, 10, 11, 12, 13, 14, 15, 19 degradation, ix, x, 19, 24, 40, 43, 46, 82, 83, 84, 85, 86, 87, 90, 94, 98, 101, 115, 116, 117, 118, 120, 125, 126, 128, 129, 130, 131, 132, 134, 136, 139, 140, 141, 142, 143, 150, 154 degradation process, 101, 128, 154 degraded area, 73, 107, 150 denitrification, 66 Denmark, 53 Department of Agriculture, 121 deposition, 84, 86, 88, 114, 119 deposits, 84, 119, 121 depth, x, 2, 22, 26, 35, 48, 49, 50, 56, 77, 80, 86, 89, 115, 121 destruction, 18, 82, 149 detection, 12, 64 detoxification, 39, 44, 52 developed countries, 129, 131 developing countries, 128, 131, 137, 139, 142 direct observation, 16 disaster, 4 discharges, 7 diseases, 73, 148 disequilibrium, 79, 81, 82, 84, 85, 86, 149 distilled water, 63 distribution, 12, 66, 132, 139 diversity, 10, 74, 75, 77, 86, 89, 90, 116, 118, 119, 120, 121, 131, 143, 146, 151, 153 drainage, 2, 26, 88, 151 drinking water, 2, 14 drought, 129, 148, 149, 150, 151, 152, 155 drying, 151 dumping, 145 dynamic systems, 81 E Earth Summit, 143 earthquakes, 81 earthworms, 46, 50, 56, 66, 87 ecological processes, 45, 113 ecological restoration, 115, 117, 120, 123, 148 ecological systems, 2, 9, 10, 18, 105 ecology, x, 69, 70, 110, 113, 122

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162

Index

economic development, ix economic incentives, 24 economics, 69, 70 ecosystem, ix, x, 10, 24, 38, 45, 48, 49, 50, 52, 84, 85, 86, 113, 114, 116, 119, 120, 122, 125, 128, 129, 135, 137, 139, 141, 145, 146, 149, 150, 154 eco-tourism, 73 education, 109 EEA, 3, 4, 6, 7, 19 efficiency criteria, 37 El Niño, 28 e-learning, 109 electrical conductivity, 136 electrophoresis, 65 employment, 75, 139 employment opportunities, 139 encouragement, x, 47 endangered, 75 energy, x, 41, 49, 79, 80, 81, 82, 83, 84, 85, 88, 119, 126, 134, 137, 139, 143 energy conservation, 79, 82 energy consumption, 84 energy input, 134 energy supply, 137 energy transfer, 80 enforcement, 6 engineering, 18, 22 England, 2, 3, 8, 9, 14, 19 ENS, 28, 29, 30, 32 environment, ix, x, 1, 3, 5, 6, 7, 8, 9, 11, 16, 19, 40, 47, 48, 52, 62, 63, 86, 107, 110, 119, 125, 128, 141, 145, 146, 150, 153 environmental conditions, 81, 86, 118, 134, 151 environmental effects, 114 environmental factors, 87 environmental impact, 13, 17, 18, 53 environmental protection, 11, 86 Environmental Protection Act, 6, 19 environmental quality, 82 environmental services, 38 environmental sustainability, 134 environmental variables, 88 environments, 19, 135, 138, 141 enzyme, x, 46, 53, 55, 56, 61, 62, 64, 65, 66 enzymes, 46, 55, 65 EPA, 6, 8, 9, 19 EPR, 7 equilibrium, 79, 80, 81, 82, 83, 85, 86, 87, 88, 98, 105, 107, 123 equipment, 56 equity, 75, 137 erosion, 21, 23, 24, 25, 27, 32, 34, 35, 36, 37, 38, 44, 75, 79, 80, 82, 83, 85, 86, 87, 88, 89, 90, 93, 94,

95, 96, 98, 100, 101, 102, 108, 111, 125, 126, 128, 130, 131, 133, 135, 137, 139, 149, 152, 154 ester, 13 ethanol, 64, 138 ethics, 69, 70 EU, 7 Europe, 7, 35, 110, 133 European Community, 4 evaporation, 43, 129, 152 evapotranspiration, 30 evidence, 2, 11, 16, 18, 30, 115, 122 evolution, 79, 81, 82, 83, 85, 87, 88, 107, 109 expertise, 11, 13, 18 exposure, 2, 10, 88 extraction, 114, 115, 117 extreme precipitation, 33 F families, 73, 74, 147 family planning, 74 farmers, 21, 23, 24, 25, 34, 40, 41, 134 farming techniques, 45 farmland, 38, 137 farms, 21, 23, 24, 34, 48, 121 fauna, 49, 75, 116, 119, 150 feed additives, 45 feedstock, 138 fencing, 148 fertility, ix, 39, 40, 44, 45, 52, 53, 67, 83, 125, 134, 135, 137, 139, 146, 147, 149, 153, 154 fertilization, x, 52, 56 fertilizers, 39, 40, 41, 45, 47, 48, 50, 51, 56, 66, 73, 126, 134, 139, 149 fiber, 125, 128, 153 fibers, 41 field crops, 51, 155 financial, 14, 18, 34, 36, 135 financial resources, 34 fires, 2 fish, 121 fishing, 9 fitness, 9 fixation, 147, 151 flocculation, 49 flooding, 130 floods, 81, 130, 138 flora, 75, 145, 150, 151, 154 flora and fauna, 150 flowers, 151 fluctuations, 38 food, 2, 8, 10, 39, 41, 45, 52, 116, 121, 125, 126, 128, 134, 135, 137, 138, 139, 152

Index food chain, 10, 138 food production, 116, 137, 139 food security, 39, 128, 134, 137, 139 force, 116, 130 Ford, 2, 19, 118, 121 forecasting, ix, 21 forest fragments, 34 forest management, x, 69, 70, 76, 122 forest resources, 70, 78 forest restoration, 122 formation, 58, 59, 79, 82, 87, 88, 131, 146 fragility, 82 France, 111 freshwater, 2, 22 frost, 117, 123 fruits, 151 funds, 24 fungi, 46, 87, 146, 147, 148, 150, 155 fungus, 151, 156

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G GDP, 6 gel, 65 genus, 67 Geographic Information System, 80, 89 geography, 23 geology, 1, 14, 89, 90, 92, 111 Germany, 121 germination, 122 ginseng, 67 GIS, 20, 26, 35, 38, 109, 110 global scale, ix, 3 global warming, 131, 139 goods and services, 77 governance, 72 governments, 12 grades, 152 grass, 17, 45, 53, 56, 58, 59, 62, 126, 130 grasses, 27, 57, 59, 61, 62, 121, 138, 148, 151 grasslands, 73 gravity, 81, 85 grazing, 23, 24, 34, 35, 36, 38, 74, 85, 86, 113, 119, 131 Great Britain, 155 Green Revolution, 126 greenhouse, x, 2, 44, 142, 143 greenhouse gas, x, 2, 44, 143 greenhouse gas emissions, 2 greenhouse gases, x, 44 Gross Domestic Product, 133 groundwater, 2, 3, 6, 7, 9, 12, 13, 17, 49, 130

163

growth, 27, 40, 45, 49, 52, 53, 63, 64, 66, 79, 82, 86, 116, 118, 119, 122, 126, 128, 130, 135, 137, 141, 143, 145, 146, 147, 148, 149, 151, 153, 155 growth rate, 135 guidance, 7, 8, 9, 114 guidelines, 116 H habitat, 116, 118, 119, 121, 146 habitats, 2, 3, 9, 114, 116, 118, 119, 122 hardness, 94 harvesting, 49, 148, 150, 155 hazards, 2, 86 health, 2, 4, 8, 9, 10, 11, 14, 18, 40, 45, 48, 52, 73, 148, 151, 155 health care, 73 health care system, 73 health effects, 8, 10 height, 30 herbicide, 151 herpetofauna, 121 heterogeneity, 10, 114, 121 highlands, 38 history, 8, 19, 21, 47, 81, 86, 91, 105 Honduras, 25, 38 horses, 42 host, 148 House, 142 housing, 1, 2, 11 human, ix, 1, 2, 3, 4, 6, 9, 10, 11, 14, 18, 22, 39, 40, 41, 52, 69, 72, 74, 77, 80, 86, 87, 88, 91, 93, 99, 113, 114, 116, 117, 119, 126, 128, 129, 131, 134, 137, 138 human actions, 93 human exposure, 11 human health, ix, 1, 2, 3, 4, 6, 9, 10, 11, 14, 18, 52 human values, 69, 72, 74 humidity, 27 humus, 46, 146, 153 hybrid, 136 hydrolysis, 136 hydrosphere, 81 hydroxide, 64 hydroxyl, 56 hypothesis, 140 I ideal, 18, 23 identification, 3, 4, 8, 16, 67, 150 imagery, 26 images, 26

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164

Index

immigration, 154 immobilization, 51, 147 improvements, x, 36 income, 72, 75, 76 increased competition, 135 incubation time, 64 India, xiii, xiv, 25, 39, 41, 42, 43, 44, 53, 55, 56, 69, 70, 71, 72, 73, 74, 76, 77, 78, 125, 126, 127, 128, 129, 131, 132, 133, 136, 139, 140, 141, 142, 143, 145, 148, 155 indirect effect, 10, 49 Indonesia, 38 industrial revolution, 85 industrial wastes, 40, 46, 98, 142 industrialization, 126 industrialized countries, ix, 3 industries, 67, 75, 129 industry, 41 inequality, 23 infection, 51 infrastructure, 1, 2, 9, 11, 18, 93 ingestion, 2, 10 initiation, 136, 140 injure, 151 injury, 9, 151 inoculation, 145, 147, 150, 154, 155 inoculum, 151 insects, 45, 122, 131 institutions, 69, 72, 74, 126 integration, 13, 18, 89 interdependence, 70 interference, 9 intervention, ix, 1, 12, 80, 86, 99, 106, 107, 119 invasions, 119 investment, 35, 134 investments, 119 ion-exchange, 59 ions, 56, 58, 59, 61 Iowa, 121 Iran, 133 Ireland, 6 iron, 40, 56, 59, 146 irrigation, 126, 128, 130, 139, 152 isolation, 10, 17, 18 issues, ix, 1, 6, 8, 12, 13, 23, 35, 39, 53, 113, 137 Italy, 37, 109, 110 K K+, 50 Kenya, 25, 37, 135, 141 kidney, 18 kinetics, 59

L lactic acid, 64 lakes, 2 land tenure, 23 landscape, x, 24, 26, 70, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 93, 96, 99, 100, 101, 105, 107, 109, 110, 111, 114, 115, 116, 120, 121, 122 landscape geomorphologic dynamics (LGD), x landscapes, x, 8, 79, 80, 85, 88, 89, 90, 114, 116, 119, 121, 122 laws, 72, 76, 85 leaching, 2, 3, 16, 40, 49, 51, 52, 128, 129, 154 lead, 23, 70, 79, 80, 82, 86, 88, 107, 130, 135, 139, 154 Lebanon, 141, 143 legislation, 3, 8, 9 legume, 117, 119 life cycle, 121 light, 22 limestone, x, 93, 94, 146, 151, 152, 153, 155, 156 liquid chromatography, 65 lithology, 89, 90, 92 livestock, 9, 16, 23, 34, 35, 39, 41, 42, 45, 47, 85, 86, 98, 108 local authorities, 6 local government, 47 loci, 105 logging, 122, 126, 130 longevity, 147 Love Canal, 4, 19 LSD, 57, 58 lying, 117 M machinery, 108 macronutrients, 53 magnesium, 40, 50 magnitude, 3, 4, 10 majority, 6, 10, 24, 41, 49, 83, 85 mammals, 121 man, 9, 147 management, ix, x, 1, 4, 5, 6, 7, 8, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 24, 25, 26, 27, 29, 30, 32, 34, 35, 36, 37, 38, 44, 45, 47, 51, 52, 69, 70, 72, 75, 76, 77, 78, 80, 91, 105, 106, 107, 113, 114, 115, 118, 119, 122, 123, 135, 137, 141, 156 manganese, 40, 146 manipulation, 56 manure, 3, 39, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 66, 67, 137, 155 mapping, 89, 141

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Index marsh, 121 mass, 46, 80, 82, 83, 84, 93, 94, 95, 98, 100, 125, 128, 131, 154 materials, 43, 46, 50, 67, 83, 84, 85, 87, 88, 93, 145, 150, 152 matter, 9, 39, 44, 46, 50, 54, 56, 79, 83, 84, 85, 88, 131, 135, 146, 152, 154 MBP, 62 measurement, x, 67 media, 17, 63, 122 Mediterranean, 93, 110 Metabolic, 62 metabolism, 40, 49, 50 metals, 26 meter, 26 methanol, 64 methodology, 79, 80, 88, 89, 109 Mexico, xiii, xiv, 38, 113, 114, 120, 123 Mg2+, 48 microbial community, 49, 62 microbiota, 63, 147 microclimate, 153 micronutrients, 40, 50, 146 microorganisms, 46, 51, 56, 59, 62, 63, 65, 67, 146, 147, 150, 152, 155 mineralization, x, 49, 50, 53, 55, 56, 58, 59, 60, 66, 146, 147, 153, 155 Miocene, 95 mixing, 87 modelling, 16 models, x, 28, 35, 38, 113, 114, 117, 120, 156 modernization, 72 modifications, 28, 82 modus operandi, 70 moisture, 57, 75, 88, 148, 153 moisture content, 57 mold, 118 molybdenum, 40 monopoly, 22 morbidity, 16 morphogenesis, 79, 82, 83, 84, 85, 93, 98, 102, 105 morphology, 83, 84, 89, 93 mosaic, 85, 114 MSW, 55, 56, 57, 58, 59, 60, 61, 62 multidimensional, 125, 126 multiple factors, 140 municipal solid waste, 40, 46, 55, 56, 57, 61, 62 mutation, 9 mycorrhiza, 148 N Na+, 50

165

NaCl, 65 native species, 119 natural habitats, 12 natural hazards, 81 natural resource management, 69 natural resources, 9, 47, 70, 85, 105, 126 nature conservation, 110 negative effects, ix, 40 negative relation, 18 Nepal, 128, 133, 142 Netherlands, 38, 123, 141 next generation, 140 nitrification, 155 nitrogen, 26, 40, 52, 53, 56, 57, 58, 116, 117, 118, 135, 142, 146, 147, 149, 150, 151, 152, 154 nitrogen fixation, 135, 146, 154 nitrogen-fixing bacteria, 150 NMR, 54 N-N, 48, 49 normal distribution, 32, 33 North America, 26, 35, 119, 122, 133, 142 North American Free Trade Agreement, 119 Northern Ireland, 6 null, 83 nutrient, x, 25, 27, 39, 41, 45, 47, 48, 49, 51, 52, 53, 56, 66, 67, 86, 87, 117, 128, 129, 130, 135, 140, 145, 146, 147, 150, 151, 154, 155, 156 nutrient concentrations, 117 nutrient enrichment, 156 nutrients, 40, 41, 42, 45, 48, 49, 50, 51, 52, 56, 62, 66, 85, 86, 87, 116, 126, 131, 134, 137, 142, 146, 147, 148, 149, 150, 151, 153, 154 nutrition, 148 O OECD, 142, 155 oil, x, 2, 3, 40, 41, 44, 87, 105, 138 operating costs, 13 operations, 22, 24, 52 opportunities, 37, 86, 137 optimization, 45, 151 organ, 2 organic matter, ix, 26, 39, 40, 41, 44, 46, 50, 53, 56, 59, 67, 84, 87, 88, 121, 131, 135, 137, 145, 146, 149, 150, 152, 154, 155 overgrazing, 35, 130, 138 ownership, 69, 76 oxidation, 146 oxygen, 149

166

Index

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P Pacific, 22, 78, 133 Pakistan, 127, 132 palm oil, 143 Panama, vii, ix, 21, 22, 23, 24, 34, 35, 36, 37, 38 Panama Canal Watershed (PCW), ix, 21, 22, 34 paralysis, 11 parameter estimates, 36 pasture, 25, 26, 30, 34, 35, 85, 129, 130, 133 pastures, 35, 119, 126, 130 pathogens, 151 pathways, 2, 10, 11 PDL, 3, 5, 12 performance indicator, 29 permeability, 87, 94 permit, 80 PES, 21, 26, 30, 34, 35, 36 pesticide, 40, 47 pests, 45 pH, 26, 46, 48, 50, 56, 57, 58, 59, 63, 64, 65, 75, 87, 135, 136, 137, 146, 149, 154 phenol, 67 Philadelphia, 110 phosphate, 48, 49, 55, 56, 59, 60, 61, 63, 64, 65, 66, 67, 146, 147, 148 phosphates, 64, 67 phosphorous, x, 49 phosphorus, x, 26, 56, 57, 59, 60, 62, 66, 67, 147, 148, 151, 155 photographs, 16 physical characteristics, 115 physical properties, 135, 154, 155 physical structure, 44 physicochemical properties, 66 physics, 85 phytoremediation, 17 pigs, 42 pilot study, 21, 77 plant establishment, 115, 119 plant growth, x, 27, 40, 44, 49, 50, 66, 67, 147, 148, 150, 151, 155 plants, 10, 23, 35, 40, 41, 50, 51, 75, 85, 86, 101, 115, 116, 118, 120, 122, 126, 128, 137, 138, 142, 143, 146, 147, 148, 150, 151, 152, 154, 156 plasticity, 94 playing, 7 Pliocene, 95 policy, ix, 1, 4, 5, 6, 7, 8, 11, 12, 13, 14, 15, 21, 25, 35, 72, 75, 77, 129 policy making, 25, 35 pollutants, x, 3, 16, 17, 44, 49, 151 pollution, 2, 3, 5, 6, 7, 9, 12, 19, 38, 45, 49

polyacrylamide, 65 ponds, 148 pools, 49, 50, 51 population, 22, 23, 27, 42, 44, 51, 75, 118, 125, 126, 128, 129, 145, 146, 149 porosity, 40, 51, 135, 151 Portugal, x, xiii, 79, 80, 109, 111 positive feedback, 122 potassium, 26, 50, 57 potential benefits, x, 125, 128 poultry, 42 poverty, 129, 143 Precautionary Principle, 19 precipitation, 23, 27, 28, 30, 31, 58, 87, 129 preparation, 148 preservation, 126 prevention, 5, 6, 7, 8, 13, 23, 24, 25, 35, 128, 129 primary function, 72 principles, 37, 45, 105 private sector, 75 probability, 10, 31, 32, 33, 83, 84, 86 probability density function, 32, 33 probability distribution, 31 producers, 27 production costs, 41 production function, 72 project, ix, xi, 13, 21, 25, 34, 35 proliferation, 63, 135 propagation, 116, 120, 141 protection, ix, 1, 7, 9, 11, 13, 70, 75, 86, 105, 108, 137 proteins, 65 prototype, 20 pruning, 135, 143 publishing, 141, 143 Puerto Rico, 120 pulp, 153 purification, 65, 66, 105 Q quantification, 91 R radiation, 27, 84 rainfall, 23, 85, 87, 93, 129, 130 raw materials, 43, 128 reality, 19 receptors, 2, 9, 10, 17 recession, 27 recognition, 113 recommendations, 35, 36

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Index recovery, 80, 105, 107, 116, 119, 145, 146, 154 recovery process, 154 recreation, 75, 105 recurrence, 155 recycling, 12, 15, 39, 45, 53, 56, 137 redevelopment, ix, 1, 4, 6, 8, 11, 80, 107 redistribution, 85 regenerate, 2 regeneration, 6, 8, 74, 75, 105, 121, 122, 145, 149, 151, 154 regression, 26, 33, 59 regression model, 33 regulations, 5, 6, 72 regulatory framework, 18 regulatory requirements, 17 rehabilitation, 12, 17, 120, 128, 129, 132, 137, 141, 143, 148, 149, 153, 154 reliability, 29, 35, 111 remediation, 6, 7, 8, 10, 12, 13, 16, 17, 18, 19 remote sensing, 35, 140 renewable fuel, 139 requirements, 5, 13, 41, 73, 81, 116, 126 researchers, 153 residues, 39, 41, 44, 46, 49, 50, 66, 86 resilience, 105 resistance, 148 resolution, 26, 34 resource management, 125, 126 resource utilization, 134 resources, ix, 2, 7, 10, 12, 13, 24, 25, 40, 43, 45, 70, 72, 75, 85, 118, 119, 126, 127, 134, 135, 138, 140 respiration, x, 55, 56, 57, 62 response, 4, 53, 86, 94, 121, 122 restoration, ix, x, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 125, 126, 128, 137, 139, 142, 145, 146, 149, 150, 154, 155 restoration programs, 137 restored ecosystem, 151 revenue, 73 rights, 9 risk, ix, 3, 4, 5, 7, 9, 10, 12, 13, 14, 16, 21, 35, 85, 86, 99, 102, 105, 129, 138 risk assessment, 10, 13, 14, 16 risk factors, 10 risk management, 13, 16 risks, 2, 5, 8, 9, 10, 12, 14, 16, 137 root, 40, 49, 51, 67, 135, 141, 147, 148, 150, 151, 152, 154 root growth, 40, 51 root system, 154 root zones, 151 roots, 35, 44, 51, 86, 130, 131, 135, 146, 148, 151, 154

167

rotations, 35, 135 routes, 10 Royal Society, 8, 19, 20 rules, 72 runoff, 23, 31, 38, 45, 49, 83, 86, 99, 130, 137, 149, 153 rural areas, 103 rural development, 137 rural people, 129 S safety, 52 salinity, 40, 51, 125, 126, 128, 130, 149 salts, 53, 130, 136, 137 samplings, 77 sanctions, 24 saturation, 9 sawdust, 152 scarcity, 25, 35 scavengers, 154 scholarship, 120 science, 110, 155 scope, 139 SDS-PAGE, 65, 66 sea level, 23 seasonality, 23 secretion, 50, 62 security, 77, 128, 137 sediment, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 84, 86, 148 sedimentation, 21, 22, 24, 25, 32, 83 seed, 73, 122, 138, 148 seeding, 119 seedlings, 151, 155 self-regulation, 105 sensitivity, 28, 32, 82 serum, 65 serum albumin, 65 service provider, 24 service quality, ix services, x, 24, 38, 74, 114, 116, 120, 125, 128, 129, 137, 141 sewage, 53 shade, 117 shape, 87, 145 sheep, 42, 44, 130 shelter, 128 shoot, 143 shortage, 150 showing, ix, 40, 101 shrubs, 27, 108, 130, 135, 148, 149 signals, 156

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168

Index

simulation, ix, 21, 25, 26, 27, 34, 38 simulations, 27, 32, 34 sludge, 53, 138 SO42-, 48 social benefits, 18 social development, ix, 137 social indicator, 12 social interests, 116 social justice, 45, 52 society, 47, 74 sodium, 65, 136 software, 14, 26 soil erosion, 39, 45, 49, 82, 83, 85, 86, 93, 100, 102, 105, 125, 126, 128, 129, 149, 153, 154 soil organic matter in (SOM), ix soil particles, 130, 146 soil pollution, 12 soil type, 13, 40, 98 solid waste, 9, 148 solubility, 67 solution, ix, 1, 4, 8, 12, 13, 16, 17, 18, 41, 64, 65, 66 sorption, 67 South America, 133 South Asia, 132 South Korea, xiii, xiv, 55, 67 sowing, 47 SP, 109 SPA, 57, 61, 62 Spain, 53, 111 species, x, 27, 35, 67, 74, 75, 86, 101, 115, 116, 117, 118, 119, 120, 126, 135, 136, 137, 138, 140, 141, 147, 148, 149, 150, 151, 154, 155, 156 species richness, 75, 116, 117, 118 spectroscopy, 54 spending, 139 Sri Lanka, 133 SS, 116, 117, 119 stability, x, 43, 52, 79, 80, 81, 82, 83, 87, 105, 107, 108, 129, 150, 151 stabilization, 46, 52, 149 stable states, 116, 119, 122 stakeholders, 7, 12, 115, 117, 119, 120 state, 5, 12, 19, 24, 25, 81, 82, 83, 87, 113, 114, 115, 116, 117, 118, 120, 139 states, 3, 4, 17, 72, 82, 83, 84, 113, 116, 118, 119, 122 statistics, 129 sterile, 63 stock, 73, 75 storage, 7, 21, 22, 126, 137, 148, 154 storms, 23, 129 stress, 40, 51, 148, 149, 150, 155

structure, 5, 13, 18, 23, 42, 49, 83, 85, 94, 109, 113, 115, 117, 118, 120, 121, 122, 128, 129, 130, 131, 135, 146, 151, 153 style, 72 sub-Saharan Africa, 133 substrate, 46, 57, 62, 65, 148 substrates, 56, 58, 59, 60, 138, 147, 154 succession, 74, 119, 120, 121, 122, 139, 146, 149, 150, 151, 153, 155 sulfur, 40 Sun, 67 surface area, 46, 152 survival, 116, 117, 119, 120, 122, 135, 140, 150 survival rate, 117 susceptibility, 90, 95 sustainability, 12, 13, 17, 18, 39, 45, 70, 81, 82, 105, 149, 150 sustainable development, xiv, 8, 12, 70, 78, 82, 125, 137 sustainable management, ix, x, 1, 12, 18, 20, 77 Sweden, 77 Switzerland, 143 symbiosis, 146, 148 synchronization, 51, 72 synthesis, 140 T tangible benefits, 75 tanks, 148 target, 12, 14, 81, 117 Task Force, 133, 141 technical support, 24 techniques, 18, 23, 24, 34, 56, 86, 109, 114, 135 technologies, 12, 17 technology, x, 17, 18, 35, 40, 41, 46, 138, 145, 146, 154 temperature, 27, 87, 115, 135, 151, 153 terraces, 24 terrestrial ecosystems, 20 territorial, 2, 9 testing, 72, 74 texture, 26, 56, 87, 129, 146, 148, 149, 153 threats, 12, 125 timber production, 116, 119 time periods, 27 tissue, 148 tones, 2, 129 tourism, 73 toxic effect, 9, 10 toxic substances, 8 trade, 17, 18 trade-off, 17, 18

Index traditional practices, 72 traits, 138 transformation, 67, 72, 146 transformations, 54 transport, 7, 27, 85, 148 treatment, 5, 8, 17, 18, 55, 56, 58 tropical forests, 35, 37 Turkey, 110 turnover, 135

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U U.S. Department of Agriculture, 38 UK, vii, ix, xiii, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 18, 19, 20 UN, 127 unacceptable risk, 3, 6 UNDP, 132 UNESCO, 23, 37, 38 United, 121, 127, 128, 131, 132, 138, 142, 143 United Nations, 128, 131, 132, 138, 142, 143 United Nations Convention to Combat Desertification, 143 United States, 121, 127 urban, 19, 20, 22, 23, 26, 27, 41, 85, 87, 89, 91, 98, 100, 101, 102, 105, 122, 129 urban areas, 87 urban population, 22 urbanization, 114, 125, 126 urea, 40, 48, 52 USA, 37, 38, 52, 109, 110, 111, 120, 127, 133 USDA, 23, 26, 38, 155 V validation, 26, 27, 28, 29, 30, 31, 32, 33, 36 vapor, 151 variables, 87 variations, 28, 51, 131 varieties, 126 vector, 26 vegetables, 47 vegetation, 16, 35, 44, 77, 79, 80, 82, 83, 85, 86, 87, 88, 89, 93, 94, 95, 96, 98, 99, 100, 101, 102, 103,

169

105, 108, 109, 113, 114, 116, 117, 118, 119, 121, 126, 127, 130, 137, 138, 145, 146, 148, 149, 151, 154 vegetative cover, 23, 35, 149 velocity, 87, 129 vulnerability, 23 W wages, 139 Wales, 2, 3, 9, 19 Washington, 38, 142, 155 waste, ix, 1, 6, 7, 39, 41, 42, 47, 50, 53, 54, 58, 93, 100, 129, 145, 148, 152 waste disposal, ix, 1, 100 waste management, 6, 7 water absorption, 152 water quality, 19, 25, 156 water resources, 2, 3, 9, 18, 24, 25, 126 watershed, ix, 21, 22, 23, 24, 25, 26, 30, 31, 32, 34, 35, 36, 38, 99, 100, 114 weakness, 85 well-being, 38 West Africa, 25 wild animals, 9, 130 wildfire, 86, 100 wind speed, 27 Wisconsin, 52 wood, 73, 75, 152 wood products, 75 woodland, 98 workers, 23, 48, 149 World Bank, 134, 143 worldwide, 39, 41, 125, 127, 129, 133, 138, 139 Y yield, x, 21, 22, 25, 27, 30, 31, 32, 33, 34, 35, 36, 44, 51, 53, 56, 126, 135 Z zinc, 40, 146