Sustainability in Developing Countries: Case Studies from Botswana’s journey towards 2030 Agenda [1st ed.] 9783030483500, 9783030483517

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Susan Osireditse Keitumetse Luc Hens David Norris   Editors

Sustainability in Developing Countries Case Studies from Botswana’s journey towards 2030 Agenda

Sustainability in Developing Countries

Susan Osireditse Keitumetse  •  Luc Hens David Norris Editors

Sustainability in Developing Countries Case Studies from Botswana’s journey towards 2030 Agenda

Editors Susan Osireditse Keitumetse Okavango Research Institute (ORI) University of Botswana Maun, Botswana David Norris University of Botswana Gaborone, Botswana

Luc Hens Department of Economics, Entrepreneurship and Business-Administration Sumy State University Sumy, Ukraine Vlaamse Instelling voor Technologisch Brussels, Belgium

ISBN 978-3-030-48350-0    ISBN 978-3-030-48351-7 (eBook) https://doi.org/10.1007/978-3-030-48351-7 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG. The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

The year 2020 marks the ten-year period before 2030 agenda for sustainable development (SD) elapses. This timeframe has been declared “A Decade of Action for the Sustainable Development Goals” by United Nations Secretary-General. During this period, 17 sustainable development goals (SDGs) and their 169 targets adopted in 2015 must be delivered worldwide. Baseline knowledge becomes necessary in this regard. This book volume is produced as an effort to add to the decade of action for SDGs by addressing the task of “engagement of stakeholders”—whereby African academic publishing provides the voice (experiences as outlined by authors) that propels action with direction. This mode of sustainability reporting is lacking in most African regions. The United Nations Secretary-General, Antonio Gutteres, in his 2019 address to a High-Level Political Forum on Sustainable Development said: “I am calling on civil society, grassroot organizations, media, private sector, unions, academia and others to mobilize partnerships like never before” (https://www.un.org/sg/en/content/sg/speeches/2019-09-24/remarks-high-level-political-sustainable-development-forum). This publication adds this call by contributing knowledge that feeds into actions toward the 2030 agenda. Although the African continent hosts a hub of experiences with potential to provide quality case studies for the content of the 17 SDGs, African academia lacks behind in contributing knowledge for solutions to global challenges. This is mainly because African academics struggle to secure quality publishing platforms such as Springer, the one hosting contributions in this book. Therefore, the publication of this volume is a step forward in adding the African experience to tackling global sustainability discourse. The SDGs were developed in 2012 at the Rio Conference on Development and Sustainable Development (https://sustainabledevelopment.un.org/rio20) as a build up from the eight Millennium Development Goals (https://www.un.org/millenniumgoals/) adopted in 2000. The SDGs were launched in 2015. Contributions in this book volume provide a “dialogue with stakeholders” aspect of sustainability reporting. In addition, the book illustrates the potential of academic publishing to supplement and enhance conventional forms of sustainability v

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reporting in a developing African country such as Botswana. In engaging academic publishing as an alternative platform through which state of country sustainability is collated and described allows for more detailed descriptions and experiences on the ground, as well as increases the diversity of stakeholders who become independent “reporters” on topics addressed by the SDGs. The sample topics covered in this volume illustrate this point well. Academic publishing therefore provides an alternative reporting platform that can be used to monitor the 2030 agenda. The most conventional country experiences the achievement of SDGs usually through a designated country’s government department in a ministry. For Botswana, this is the task for the Ministry of Finance and Development Planning (https://www. bw.undp.org/content/botswana/en/home/sustainable-development-goals.html; Government of Botswana and United Nations Sustainable Development framework (UNSDF), 2017–2021). Targeted reporting from other stakeholders such as academic research can also bring insights on sustainability tracking. Unlike country reports, academic research on sustainability tracking can inform regional and continental perspectives. This approach resonates with the need to build local strategies to achieve various SGDs as outlined by the United Nations. Several stakeholders have made this book possible. In particular, we are grateful to the contributors for working hard to provide content-rich topics for the manuscript. We appreciate the publishing editor (Nitesh Shrivastava)’s patience and the publisher’s willingness to put an African viewpoint on an international academic platform. Earlier contribution by our colleague Dr Michael V. Flyman at the conceptual stage of this volume proposal is also acknowledged as it enriched the book perspective. We invite you to go through the book content and give feedback through various online academic interaction channels. Gaborone, Botswana September 2020

David Norris

Contents

1 INTRODUCTION – Sustainability Reporting in African Countries: The Research Outlet Approach ������������������������������������������    1 Susan Osireditse Keitumetse, Luc Hens, and David Norris Part I Biodiversity/Habitat 2 Potential Impact of Alien Invasive Plant Species on Ecosystem Services in Botswana: A Review on Prosopis juliflora and Salvinia molesta����������������������������������������������   11 Keotshephile Kashe, Roger Heath, Alison Heath, Demel Teketay, and Benjamin O. Thupe 3 Nutrients in a Changing Environment: Implications on the Sustainability of the Okavango Delta������������������   33 Oarabile Mogobe, Bernice Setomba, and Wellington R. L. Masamba Part II Water Management & Human-Wildlife Nexus 4 Changing the Scale and Nature of Artificial Water Points (AWP) Use and Adapting to Climate Change in the Kalahari of Southern Africa��������������������������������������������������������   51 J. S. Perkins 5 Sustainable Management of Water, Wildlife and Agriculture in Botswana: The Case of Mmadinare Area��������������   91 Masego Ayo Mpotokwane, O. M. Modise, R. N. Lekoko, and O. T. Thakadu

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Part III World Heritage 6 Linking African World Heritage and Sustainable Development: Appraisal of Policies, Concepts, Principles and Approaches to Agenda 2030 ����������������������������������������������������������������������������������������  113 Susan Osireditse Keitumetse 7 Land Use Planning, Land Development and Sustainable Management of Great Zimbabwe World Heritage Site, Masvingo Province, Zimbabwe��������������������������������������������������������������  131 Ashley L. C. Maganzo and Marlvern Mabgwe Part IV Tourism 8 Sustainable Tourism and the SDG’s in Botswana: Prospects, Opportunities and Challenges Towards 2030 ��������������������  153 Lesego S. Stone, Patricia K. Mogomotsi, Moren T. Stone, Goemeone E. J. Mogomotsi, R. Malesu, and M. Somolekae Part V Gender 9 Child Sexual Abuse (CSA) as a Gender Inequality Practice: Applying Sustainable Development Goals ��������������������������������������������  185 Nankie M. Ramabu Part VI Education 10 Environmental Sustainability Education: Driving Towards Achieving SDG 4 Through Teacher Education��������  207 Ntha Silo and M. J. Ketlhoilwe 11 Environmental Education in Botswana: Successes and Constraints Towards the 2030 Agenda��������������������������  225 Kgosietsile Velempini Part VII Institutions 12 Conservation Challenges, Resource Management and Opportunities to Sustain Wildlife Biodiversity in the Kalahari: Insights from a Local NGO, Cheetah Conservation Botswana������������������������������������������������������������  243 L. K. Van der Weyde, J. Horgan, N. Ramsden, D. Thamage, and R. Klein 13 Implementing Sustainable Development Goals at Institutional Level: The Case of University of Botswana����������������  265 Julius R. Atlhopheng, Bontle Mbongwe, and Thatayaone Segaetsho

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14 Positioning the University of Botswana Towards Achieving the Sustainable Development Goals (SDGs)������������������������  281 Goemeone E. J. Mogomotsi, Patricia K. Mogomotsi, and David Norris Part VIII Concluding Chapter 15 Realizing Sustainable Development Goals in the Southern Sub-Region of Africa����������������������������������������������������  297 Luc Hens and Susan Osireditse Keitumetse Index������������������������������������������������������������������������������������������������������������������  303

Chapter 1

INTRODUCTION – Sustainability Reporting in African Countries: The Research Outlet Approach Susan Osireditse Keitumetse, Luc Hens, and David Norris

Abstract  Sustainability reporting in most developing countries is perceived to be the sole responsibility of national governments. However, targeted reporting from other stakeholders such as research for instance can also bring insights to sustainability tracking that may complement the country perspectives. This layer adds to the “Dialogue with stakeholders” aspect of conventional sustainability reporting. Unlike country reports, research on sustainability tracking can cover regional as well as continental perspective of issues that are perceived as local. This mode of sustainability reporting is lacking in most African countries. The chapters in this book present a country research perspective on sustainability issues, outlining the situation on the ground, as well as potential solutions towards the 2030 Agenda. Keywords  Research and sustainability · Developing countries · SD Goals · Botswana · Southern Africa

1.1  Background This publication provides case studies from various stakeholders on experiences and strategies that can allow for achievement of SDGs in developing countries.

S. O. Keitumetse (*) Okavango Research Institute (ORI), University of Botswana, Maun, Botswana e-mail: [email protected] L. Hens Department of Economics, Entrepreneurship and Business-Administration, Sumy State University, Sumy, Ukraine Vlaamse Instelling voor Technologisch, Brussels, Belgium D. Norris University of Botswana, Gaborone, Botswana e-mail: [email protected] © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020 S. O. Keitumetse et al. (eds.), Sustainability in Developing Countries, https://doi.org/10.1007/978-3-030-48351-7_1

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The 2030 Agenda was conceptualized at the United Nations Conference on Sustainable Development in Rio de Janeiro, Brazil in June 2012 and has 17 Sustainable Development Goals (SDGs) together with 169 targets and at least 230 indicators. The SDGs are aimed at shaping public policy, achieving resource sustainability as well as guiding the development of human beings in their geographic setting. The most conventional country experiences on achievement of SDGs is usually through a designated country’s government department in a Ministry. For Botswana, this is the task for the Ministry of Finance and Development Planning (ref weblink: https://www.bw.undp.org/content/botswana/en/home/sustainable-development-­ goals.html; Government of Botswana and United Nations Sustainable Development framework, UNSDF 2017 – 2021). This form of reporting provides opportunities for easier monitoring of the 2030 sustainable development goals. However, this exercise is often the preserve of official government reports, rather than an engagement of wider stakeholder description of their experiences, challenges and suggestions on way forward. This volume is an example of how academia could supplement these existing forms through which obligations to report on sustainability are4 monitored in a country and region. The book provides a supplement to the conventional ‘state of environment’ reports. By engaging academic publishing as a strategy through which state of country sustainability is collated and described, the platform provides for more detailed descriptions and experiences in the reports, and also increase the variety of stakeholders who represent independent “reporters” on certain topics addressed by SDGs. This provides another form of information that can subsequently be used to monitor the 2030 Agenda through stakeholders’ individual experiences at their local contexts. This resonates with the building of local strategies (academic regional publishing here being one), to achieve the various sustainable development goal (SGDs) outlined by the United Nations (UN). Also, conventional country reports are more focused on generalized policy directions and extrapolated implementation strategies; while academia, through publishing does provide the framework for situation-analysis and grass-root experiences per topic thus offering an opportunity for the Sustainable Development milestones to be tracked. For instance, the adopted Cape Town Global Action plan for Sustainable Development (https://unstats.un.org/sdgs/hlg/Cape-Town-GlobalAction-Plan) calls for traceable data/information on sustainable development. To achieve this, countries must start with a coherent and documented discussion, and in this regard partnership with academia in this project, through publishing becomes important. Literature with similar mode of reporting on sustainability issues (Publishing) in Botswana has yielded books that can provide ideal material to compare progress or lack thereof on certain issues of sustainability in the country. The following are profiled: • Atlhopheng, J., Molebatsi, C., Toteng, E., & Totolo, O. (1998). Environmental issues in Botswana: a handbook. Lightsbooks.

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Environmental issues in Botswana: a handbook. The book was produced for environmental education into the school curricula, “…as a step towards augmenting teaching materials on Botswana’s environment. Six environmental issues of major concern to the country were identified in Botswana’s National Conservation Strategy: industrial and urban pollution; pressure on water resources; rangeland degradation; depletion of wood resources; and overuse of veld products (wild animals and wild plants, in particular wild food plants and drug plants).” ISBN: 9991271058; Publisher: Lightsbooks • Arntzen, J. W., & Veenendaal, E. M. (1986). A profile of environment and development in Botswana. A profile of environment and development in Botswana. The book provides a profile of environment and development in Botswana with a focus on agriculture and economic development. As per the abstract: This report analyses the major research findings on environment and development in Botswana. It uses a sector-oriented approach. The report gives: (a) an overview of the state of the environment in relation to economic development; (b) a review of major present and anticipated environmental problems and of presently known options to remedy them; (c) a survey of relevant legislation, institutions and development programs Record Number: 19876704565

This book volume is even more relevant for the relatively recent document “Transforming our world: the 2030 Agenda for Sustainable Development”, adopted by the United Nations at its 70th session on 21st October 2015 General Assembly. At this meeting, 17 sustainable development goals and 169 targets were outlined for every country to implement (http://www.un.org/sustainabledevelopment/developmentagenda/)

1.2  Aims and Objectives of This Publication Are: (a) Provide a handbook of evidence of what takes place on the ground where implementation of the effaced MDGs and now the 2030 agenda for SD takes place. (b) Illustrates the on-ground real-life experiences that provides challenges and opportunities for the implementation of 2030 agenda for SD. (c) Isolate (strip out) what takes place on the ground of an African country conservation efforts versus what is expected within the 17 SDGs and 2030 agenda for SD milestones. (d) Provides a framework for alternative engagement by highlighting a somewhat unique perspective of what transpires in African countries like Botswana. These experiences can later be referred to when providing support to African countries in their bid to achieve some of the sustainable development initiatives highlighted by the contributors.

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1.3  Contents The sample topics covered in this volume are as diverse as their contributors. Future volumes could collate topics per each sustainable development goal to cover all the seventeen (17) goas of the United Nations and increase the combination of stakeholders at a country level. However, this runs the risk of similar repeated observations that can nonetheless be a good output necessary to emphasize scenarios on the ground. One way to avoid similar conclusions from one country will be to make a region-focused volume that illustrates case studies from various countries, e.g. southern Africa and/or Sub-Saharan Africa. Therefore, as tempting as it was to list the 17 SDGs as sub-themes; this publication allowed contributors the freedom to choose topics for submission so that they reflect experiences on the ground as exhibited by the work of the authors. It is important to note that as per majority of topics submitted, the issue of sustainability is still highly associated with environment and education, and other areas such as world heritage, gender, and others appear to be under-represented and still need to be mainstreamed into the international policy framework. Summary of themes that emanated from the various contributions are categorized as habitat, water management and wildlife nexus; World Heritage; Tourism; Gender; Education and Institutions. The following are summaries of titles represented in the volume: Chapter 2: Invasion by alien species in the Kalahari and the Okavango Delta environments of Botswana is discussed and their impacts on ecosystem services outlined. Alien species potential to negatively impact sustainable development Goal 2 (food security) and associated is highlighted. The specific invasive plants referred to in this chapter are Prosopis juliflora and aquatic weed, Salvinia molesta on ecosystem services in Botswana. The authors observe that that P. juliflora has the potential to lower water table in water-limited ecosystems, resulting in negative impacts on biodiversity and ecosystem services, and in some areas, it inhibits growth of keystone species hindering their capacity to provide services. A Salvinia molesta invasion in the Okavango Delta, Botswana, has the potential to decrease ecosystem services. Chapter 3: With aquatic ecosystems facing multiple water quality threats, effective management of water resources is therefore critical because water quality and quantity are key drivers in maintaining ecosystem function and structure. This chapter uses the Okavango Delta as a case study to assess the spatial and temporal variations of inorganic nitrates and phosphates species within as a way to evaluate possible impact of reported land use changes on surface water quality and sustainability of the Okavango delta. The assessment is important in contributing to knowledge relating to United Nations (UN) sustainable development goal (SDG) #15 Chapter 4: By using a case on the impact artificial water provision (AWP) has had upon the sustainable management of both livestock and wildlife populations in the semi-arid savannahs of Botswana, this paper illustrates how the existing tools

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for conservation can only be meaningfully achieved when local communities are rewarded for co-existing with African wildlife and protecting essential ecological good and services. Topics covered include range management, livestock populations, wildlife populations community-based conservation approaches amongst others. Chapter 5: The topic on human-wildlife interaction and its solution, is addressed by several SDGs. Some of the possible impacts have been highlighted in this paper. However, Impact Scenario 6, shows that climate change could trigger an intense human wildlife interaction with negative consequences. This chapter uses Mmadinare village, Botswana scenario to illustrate the dynamics between agriculture by locals, wildlife and water management by the Government. The Mmadinare community, through the Mmadinare Development Trust, proposes a co-existence benefit between human wildlife relationship to enable humans and elephants to live side by side. The paper explored potential approaches to integrate sustainability into local initiatives and challenges. Chapter 6: The Sustainable Development Goals (SDGs) are now a common policy framework amongst most countries. However, they are not mainstreamed into most areas of conservation as they should be. Chapter 6 discusses the infusion of SDGs in world heritage, with emphasis on cultural heritage resources. The question of how compatible the platform of sustainable development is to African heritage resources conservation and its development needs is deliberated on through analysis of existing policies surrounding the topic. With African resources largely embedded in people who through practical interaction with the resources constantly produce and consume heritage, the chapter acknowledges that indeed SD framework is important for heritage management because the concept of needs and limitations embraced within the sustainable development framework is applicable to African cultural heritage resources. As such, a call for formulation, development and implementation of explicit cultural resources conservation indicators is made. Chapter 7: This chapter focuses on a case study of a World Heritage site, Great Zimbabwe ruins, to illustrate issues that arise as a result of failure to examine conservation and management of African world heritage sites from a perspective of land-use planning and development. Great Zimbabwe World Heritage Site is in the center of a contested landscape and as such, the lens of land-use planning could bring a much-needed cooperation between stakeholders, resulting in sustainable useof the monument. This study illustrates that Government’s desire to present Great Zimbabwe World Heritage Site to an international audience has nurtured the emergence of an economic value which has obscured other values that need to be addressed to achieve a sustainable use of the landscape. For instance, the proposed construction of Great Zimbabwe University campus by Government within the vicinity of Great Zimbabwe World Heritage site became an occurring concern during interviews with representatives of the local traditional chiefs. The general appreciation was that while this would have been an invaluable idea for the development of Masvingo the city, the setting was inappropriate for the sacredness of the site.

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Chapter 8: International environmental awards have demonstrated that Botswana promotes tourism to stimulate rural development, encourage environmentally sustainable development and to diversify the economy. This chapter uses this status to analyze prospects, achievements and challenges to attaining sustainable tourism in general, and how far the experiences have and can address the sustainable development goals going forward. The country has adopted a tourism policy that promotes high-paying low-volume visitors (Government of Botswana, 1990) to its pristine natural areas to advance sustainability and conservation in these biodiversity-rich spaces. In addition, the country promotes Community-­ Based Natural Resource Management (CBNRM) to encourage local communities to participate in conservation through Community Based Organizations. Discussion in the chapter illustrate mixed scenarios that can be enhanced to achieve SDGs mandate. Chapter 9: The subject of gender equality, espoused in SDG 5, is commonly assessed from factors such as access to employment and education by women and girls in African contexts, and rarely from a perspective of child sexual abuse. This chapter explores some gender elements that perpetuate CSA in Botswana by first providing the background to CSA and development in the country. Ending all forms of violence against children is discussed at a national level, with some highlights illustrating that though certain laws were amended to enhance women and children’s participation in decision making, the Botswana family system is still gendered in a way that may provide fodder for women and children to experience violence from certain social customs that may negates the country’s aspirations towards international treaties such as espoused in SDG5. Chapter 10: The quality of teacher education is a key of sustainable education indicator that is judged through equipping learners with appropriate skills and ­competences to respond to the environmental and socio-ecological risks that may plight the nation. This chapter addresses education for sustainable development (ESD) from perspective of environmental education and discusses how teacher education can draw largely on SDG 4 and the Global Action Program (GAP) priorities to realize the 2030 agenda for sustainable development. A case study of the University of Botswana’s faculty of Education is used to illustrate how ESD can be achieved at a university faculty level. Chapter 11: While Chap. 10 focused on general aspects of quality education that include environmental components, Chap. 11 takes a laser focus approach by assessing several teaching approaches in pedagogical spaces of the Okavango Delta schools in Botswana as indicators developed towards achievement of two priority action areas of the Global Action Program of Education for Sustainable Development, being (1) transforming learning and training environments and (2) building capacities of educators and trainers. Assessment of teaching approaches in pedagogical spaces is discussed as an essential initiative towards instilling effective environmental education and attaining sustainability in local education. Chapter 12: The role of NGOs in achieving sustainable development goals is espoused in SDG 17 on partnerships. Cheetah Conservation Botswana (CCB) is a not-for-profit organization that is applying a holistic approach to encourage

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community-based conservation in the Kalahari region of Botswana. CCB’s primary aim is to foster coexistence with cheetah and other large carnivores in the district and the surrounding region, with a focus specifically in the non-protected areas. A case study presented in this chapter is from the Kalahari areas of Botswana, outlining activities undertaken by CCB, with a focus on the challenges and successes in reducing livestock loss, increasing tolerance towards carnivores and adapting behaviors towards coexistence in the context of Sustainable Development Goals (SDG). In particular, the chapter illustrates examples that reflect key components related to sustainable use and management of ecosystems (SDG #12 and #15) and awareness and education (SDG #3 and #4). Chapter 13: In the advent of building knowledge economies, universities in Africa are becoming key institutions in the implementation of SDGS. This chapter provides a case study of the University of Botswana (UB)’s efforts whereby the University, in its partnership with the country’s government and other stakeholders has established an SDGs hub. “The objective of the hub is to mainstream SDGs into the institutional mandate, to enhance inclusive SDGs implementation through amplifying the messages, connecting stakeholders and activities to ensure impact”. Themes addressed by the hub are cross cutting such as community development, health, education, technology, planning, sustainable development and climate change, groundwater, policy analysis, and business programs. Chapter 14: This chapter also uses the University of Botswana as a case study illustrating operational aspects of an African university and how they can be addressed to position a University attaining both sustainability within its systems such as finance and leadership.

References Arntzen, J. W., & Veenendaal, E. M. (1986). A profile of environment and development in Botswana. Amsterdam: Institute for Environmental Studies, Free University. Atlhopheng, J., Molebatsi, C., Toteng, E., & Totolo, O. (1998). Environmental issues in Botswana: A handbook. Gaborone: Lightsbooks. Government of Botswana and United Nations Sustainable Development Framework (UNSDF) 2017–2021. https://www.bw.undp.org/content/botswana/en/home/library/un-publications/thegovernment-of-botswana-and-united-nations-sustainable-develo.html. Accessed 30 Jan 2020. Sustainable Development Goals. https://www.un.org/sustainabledevelopment/developmentagenda/. Accessed 30 Jan 2020. The State of the Environment  – Report of UNEP.  Studies in Environmental Science, Volume 23, Issue null, Pages 33–45 Environment Liaison Centre. https://doi.org/10.1016/ S0166-1116(08)71215-9

Part I

Biodiversity/Habitat

Chapter 2

Potential Impact of Alien Invasive Plant Species on Ecosystem Services in Botswana: A Review on Prosopis juliflora and Salvinia molesta Keotshephile Kashe, Roger Heath, Alison Heath, Demel Teketay, and Benjamin O. Thupe

Abstract  Perceptions about the ability of alien species to provide superior ecosystem services over the native species have motivated their importation and distribution across the world. While these species may be providing goods and services, some have now escaped the area of their introduction and invaded other ecosystems posing a threat to biodiversity and ecosystem services. Invasion by alien species threaten achievement of Sustainable Development Goal 2 (food security), 6 (water availability), 12 (sustainable consumption and production patterns) and 15 (protecting ecosystems and forests). This article discusses the potential impact of terrestrial invasive plant, Prosopis juliflora and aquatic weed, Salvinia molesta on ecosystem services in Botswana. Information for this study was collected by review of academic journal articles on the invasiveness of P. juliflora and S. molesta and their impacts on ecosystem services in Africa and other developing countries. The literature review has shown that P. juliflora has the potential to lower water table in water-­ limited ecosystems, resulting in negative impacts on biodiversity and ecosystem services. In some countries P. julifolia inhibits growth of keystone species hindering their capacity to provide services. A Salvinia molesta invasion in the Okavango Delta, Botswana, has the potential to decrease ecosystem services. It will, thus, impact negatively on the welfare of the riparian communities who depend on fishing and tourist-related activities for their livelihoods. The review contributes towards understanding of the impacts of terrestrial and aquatic invasive plant species on K. Kashe (*) · B. O. Thupe Okavango Research Institute, University of Botswana, Maun, Botswana e-mail: [email protected] R. Heath · A. Heath Plants and People Africa, London, UK D. Teketay Department of Crop Science and Production, Botswana University of Agriculture and Natural Resources, Gaborone, Botswana © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020 S. O. Keitumetse et al. (eds.), Sustainability in Developing Countries, https://doi.org/10.1007/978-3-030-48351-7_2

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ecosystem services, and importance of biodiversity and ecosystem services in achievement of Sustainable Development Goals. The review further recommends quantifiable monetary assessment of the services delivered by different ecosystems. Such assessment provides information on the value of ecosystem services and can yield information on how much is lost due to invasion by alien plant species. Keywords  Invasive species · Biodiversity · Ghanzi · Prosopis · Salvinia · Kgalagadi · Okavango Delta

2.1  Introduction Traditionally, alien plants have always been favoured over the indigenous species because of their potential to confer better production and economic benefits to commercial enterprises such as the agricultural, horticultural, fibre production and ornamental plants industries (Ferdinands et al. 2011). In addition to these commercial enterprises, importation of alien plants is also driven by the search for plants that can mitigate the effects of climate change and restore degraded lands (Gordon et al. 2008; Ayanu et al. 2015). Most of these alien plants have been selected and bred to be highly productive on marginal lands with limited inputs for economic benefits (Meyerson 2008). These desirable agronomic traits, however, also enhance invasiveness (McCormick and Howard 2013). Most species thus introduced outside their natural habitat have the inbuilt ability to grow vigorously, spread and outcompete the native species in conducive environments (Chimera et al. 2010), possibly due to the absence of natural enemies. Deliberate introductions of exotic plants for research, horticulture and forestry have been cited as the major pathways for global spread of alien invasive plants (Caley et al. 2006). In fact, these intentional introductions are more responsible for the introduction of invasive plants than accidental introductions (Drew et al. 2010). While climate change may not necessarily influence biological invasions, it is likely to exacerbate the damage they cause (Mainka and Howard 2010). When a species is introduced outside its native ecosystem, if it becomes established, it may proliferate and spread to cause harm to biodiversity, the national economy and human health (DiTomaso et  al. 2013). Invasion by alien species is only surpassed by habitat destruction as the largest threat to biodiversity (IUCN 2009) and has been cited by Millennium Ecosystem Assessment (MEA 2005) as one of the major direct drivers of biodiversity loss and degradation of ecosystem services. Biodiversity plays a central role in ecosystem functioning (Quijas et al. 2010) and, thus, is a source of provision of a suite of services to mankind (MEA 2005), and any threat or degradation of biodiversity puts livelihoods of humans at risk (Pysěk et al. 2017). It is, therefore, important to understand the ecology and

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impact of invasion on ecosystem services and biodiversity to prioritise prevention, mitigation and management strategies (Katsanevakis et  al. 2014), and to develop policy for invasive species management (Cook et al. 2007). Invasive species are now recognized as a significant cost to the economy of the affected nations worldwide. In the United States, losses due to invasion by alien invasive species were estimated at US$ 120 billion per  annum (Pimentel et  al. 2005). The annual cost to the United States, the United Kingdom, Australia, South Africa, India and Brazil amounted to US$ 336 billion (Pimentel et al. 2001) due to a reduction in the agricultural, forestry and other production systems. Furthermore, harm to infrastructure, reduction of tourism revenue, public health problems and cost of eradication, containment and management also featured in this annual cost (McCormick and Howard 2013). In Botswana, two ecosystems can be used to illustrate the impact of invasive plant species on ecosystem services. These are the Kgalagadi (which is a terrestrial ecosystem) and Okavango Delta (which is an aquatic ecosystem). These two ecosystems are used in this paper to discuss and analyse the impact of invasive plant species on ecosystem services. Invasive species affect ecosystem services - Ecosystem services are benefits that human beings extract from a natural environment (Eviner et al. 2012), such as provisioning services (material benefits from ecosystems e.g. water, food, fuel and fibre), supporting services (e.g. soil formation), regulatory services (e.g. climate, nutrient cycling, air and water purification) and cultural services (non-material benefits, e.g. recreational or educational opportunities and spiritual fulfilment) (Naidoo and Rickets 2006; Brauman et  al. 2007; De Groot et  al. 2010) (Table  2.1). Biodiversity is the framework of ecosystem functioning and its ability to provide services to man-kind (Chapin et al. 2000). Biodiversity can be a service on its own, for instance, in nature-based tourism (van Wilgen et al. 2008). As the discussions of our case study will illustrate, the impact on the two Botswana ecosystems has been observed to be negative. There is growing concern about threats to ecosystem services, and MEA (2005) reported that ecosystem services have been reduced by 60% in the last 50 years. One of the drivers of ecosystem decline is invasion by alien plant species as they Table 2.1  Ecosystem services and example of their provision Category Example service Provisioning Products obtained from ecosystem e.g. food, fiber, timber and fuel, water storage and provision. Supporting Foundation for the basic life-support processes, e.g. soil formation, habitat change, ecosystem processes, photosynthesis and food web. Regulating Regulate ecosystem processes, e.g. climate and weather regulation, pollination, water filtration, nutrient cycling, floods, fire, disease and pest regulation. Cultural Enhance the quality of human life and human well-being, e.g. aesthetic values, recreation, spiritual fulfillment, cultural heritage values and cognitive effects (research and educational opportunities). Source: Constructed from Millennium Ecosystem Assessment (2005)

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negatively impact on ecosystem processes and ecosystem functioning and consequently inhibit the provisioning of ecosystem services (Sladonja et  al. 2015). Invasion by alien invasive species can significantly alter ecosystems (Ortega and Pearson 2005) and change the type and amount of goods and services that humans derive from ecosystems (Lodge et al. 2012). For example, in a pan-European review study on invasion by marine invasive species, Katsanevakis et al. (2014) found that food provisioning was most negatively affected followed by negative impacts on ocean nourishment, recreation and tourism. Lastly, cognitive benefits, water purification and climate regulation, were ecosystem services positively impacted. In Ethiopia, Prosopis juliflora (Sw.) DC. (hereafter referred to as Prosopis) was found to impact negatively on supply of provisioning and cultural ecosystem services (Ayanu et al. 2015). In neighbouring South Africa, the impact of Prosopis on ecosystem services has been reported (Pejchar and Mooney 2009; Shacklenton et al. 2014, 2015). In the case study under discussion, it is becoming apparent that the Okavango Delta’s aquatic ecosystem will be negatively affected while the Kgalagadi ecosystem is destined to Prosopis woodland if enough measures are not put in place to limit impact of invasive species in these two ecosystems. The effect of invasion on one ecosystem service can result in a ripple effect on other services. For instance, impact on supporting services will affect regulating and cultural services, and similarly provisioning services can be disrupted by changes in regulating services (Le Maitre et al. 2011). Loss of biodiversity due to invasion by alien invasive plant species is therefore likely to undermine achievement of Sustainable Development Goals (SDGs) by 2030. For Botswana, the Department of Water Affairs has introduced a weevil for biological control of Salvinia (Kurugundla et al. 2016) for Okavango, while the Department of Forestry and Range Resources is developing Prosopis management plan for Kgalagadi district. Despite a growing body of knowledge about the importance of biodiversity and ecosystem services, risk assessment is still based on species’ ecological and economic impacts and rarely considers effects related to ecosystem services. Linkages between invasion and ecosystem services need to be established, given that energy spent on the prevention of invasion by alien species can be paid back by sustained ecosystem services, resulting from preventing its harm by invasive species (Walsh et al. 2016). Such an approach is essential for developing countries, like Botswana, whose fragile ecosystems have been invaded by invasive species, as case studies of Prosopis and Salvinia will illustrate later on. In addition, Botswana has yet to develop a policy and legislation to regulate importation and cultivation of alien plants, suggesting that invasive plant species will continue to find their way into the country through both intentional and accidental introductions, in the process making it difficult to reach SDG) goals. In terms of legislation, the country is also lacking in that the only provision for some control is in the 1916 noxious weed act (CAP 35:04), which renders a land-­ owner guilty of an offence if found growing certain listed plant species on a private property. However, the list of species is quite old and does not include the invasive plant species that have found their way into the two case study areas of Kgalagadi

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and Okavango in Botswana which inhabited the areas after the Act was enacted (Table 2.2). Biodiversity and ecosystem services are essential for the achievement of SDGs) by 2030. This article examines the impacts of terrestrial invasive plant, Prosopis and aquatic weed, Salvinia molesta Mitchell (hereafter referred to as Salvinia) on ecosystem services in Kgalagadi district and Okavango Delta, respectively. The focus is on these two plants because their invasion in the respective areas in Botswana has negatively impacted ecosystem services and stakeholders call for more aggressive management interventions. Their infestations have decreased ecosystem services in the affected areas and have motivated Government to initiate management and control strategies. The article sets the scene by describing the study area and research methods used in the study. Then, the impact of the terrestrial invasive plant on three categories of ecosystem services (Provisioning, regulating and cultural) is

Table 2.2  showing invasive plant species listed under Botswana noxious weed act and international organisations Species listed under Botswana’s 1916 noxious weed Act (CAP 35:04|) Xanthium pungens (cockleburr) Acanthospermum hispidum (starburr) Cirsium lanceolatum (bull thistle) Cannabis sativa (dagga) Tagetas minuta (Mexican marigold) Cuscutta species Hakea sericea (needle bush) Haka gibbosa (hairy needle bush) Hakea suaveolens (sweet hakea) Opuntia imbricate (imbricate cactus) Solanum auriculatum (bugtree) Opuntia aurantiaca (jointed cactus) Datura ferox (large stramonium) Datura stramonium (stramonium) Datura tatula (purple thornapple) Argemone Mexicana (Mexican poppy) Acanthospermum austrate (prostrate starburr) Salvinia molesta Eichhornia crassipes (water hyacinth) Tribulus terrestris (Devil’s thorn) Amaranthus thunbergii (poorman’s spinach) Alectra vogelli (yellow witchweed) Striga asiatica (red witchweed)

Species listed by IUCN (2019) and CABI (2019) Abrus precatorius (rosary pea) Bidens pilosa (blackjack) Cardiospermum grandiflorum (balloon vine) Commelina benghalensis (wandering jew) Lagarosiphon major (African elodea) Launaea intybacea Leucaena leucocephala (leucaena) Oxycaryum cubense (Cuban bulrush) Paspalum crobiculatum Ricinus communis (castor bean) Rottboellia cochinchinensis (itch grass) Senecio inaequidens (south African ragwort) Trapa natans (waterchestnut) Conyza bonariensis (hairy fleabane) Cyperus rotundus (purple nutsedge) Cenchrus biflorus (Indian sandbur) Melia azedarach (China berry) Flaveria bidentis Prosopis species (mesquite) Verbesina encheloides (wild sunflower)

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presented. It is, then, followed by a similar discussion on aquatic ecosystems. The final section concludes the paper and suggests policy recommendations.

2.2  Study Areas and Methods The study areas for this paper are the Kgalagadi and Ghanzi districts and the Okavango Delta in Ngamiland district of Botswana (Fig. 2.1). The first two areas have been invaded by Prosopis juliflora and the Okavango Delta by Salvinia molesta. Information for this study was collected primarily from a review of historic and recent literature published following fieldwork in the areas. A search for research fieldwork results published in peer reviewed journal articles was conducted using combinations of the following key search terms: invasive plants, biological invasions, biodiversity, ecosystem services, millennium ecosystem assessment, Okavango Delta, Prosopis, Salvinia, Africa and Botswana. As a follow up to the keyword searches, the identified publications were selected based on a review of

Fig. 2.1  Map of the study areas

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their abstract. Additional information was also sourced from government reports, statistical reports, library and internet searches.

2.3  Case Studies of Some Key Invasive Species in Botswana The previous section discussed in general the impact of alien invasive species on ecosystem services. This section focuses on two alien plants, namely a terrestrial invasive, Prosopis, and an aquatic weed, Salvinia in their respective areas of the Kgalagadi and the Okavango in Botswana. The former was intentionally introduced with a desire to increase ecosystem services and the latter found its way accidentally into the Okavango Delta system.

2.3.1  Kgalagadi District Livelihood activities in Kgalagadi and Ghanzi districts are limited to livestock farming due to the semi-arid to arid climate that cripples arable farming. Their livestock depend on communal rangelands which have been invaded by Prosopis, for grazing.

2.3.2  Okavango Delta The riparian communities around the Okavango Delta derive their livelihood from the aquatic system of the Delta through fish trading and tourism related activities. However, these services are under threat due to frequent infestation of the Delta by Salvinia.

2.3.3  Prosopis juliflora (Sw). DC. (Fabaceae) Prosopis originates from South and Central America, is a woody leguminous species adapted to arid and semi-arid regions and was introduced to the Kgalagadi District of Botswana as an ecosystem engineer to stabilize sand dunes and rehabilitate degraded land in the arid southwest part of the country. Restoration of degraded land is an essential step in increasing the provision of ecosystem services as well as arresting biodiversity losses (Bullock et al. 2011). Prosopis are intentionally introduced to increase ecosystem services, but they can escape intended use and decrease supply of ecosystem services from other ecosystems. Prosopis species are classified as invasive species in Australia, Ethiopia, India, Kenya and South Africa (Shackleton et al. 2014). Their stands are usually comprised of different species and their hybrids

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(Shackleton et al. 2016). Prosopis can positively contribute to achievement of Goal 15 (combating desertification and reversing land degradation). Conversely, it is invasive and is a threat to attainment of Goal 2 (food security), 6 (water availability) and 12 (sustainable consumption and production patterns). 2.3.3.1  Provisioning Services Prosopis species provide multiple ecosystem services (Table  2.3), such as shade provision for livestock, fodder production, fuel wood, timber for furniture production and construction (Zimmermann et al. 2006; Boy and Witt 2013). It offers similar ecosystem services in Kgalagadi District in Botswana and is part of the livelihood of low-income communities in the area by providing fuel wood, shade, timber and feed for livestock. However, in South Africa, the ecosystem services from Prosopis are said to be less valuable than originally thought and most stakeholders are now calling for more rigorous interventions (Shackleton et al. 2015). In Botswana, the species has escaped its intended area of introduction and spread into adjacent Ghanzi District. The Prosopis species are now estimated to cover an area of about 5110 ha in both Kgalagadi and Ghanzi Districts (Thobega 2015). The species is now widespread covering grazing areas and reducing biodiversity and resulting in ecosystem disservices to the local people in the affected districts. Prosopis species hybridise and form dense monoculture stands with impenetrable thorn thickets, and as Walsh et al. (2016) have observed in South Africa, the individual plants within dense infestations fail to provide services i.e. they are too small to provide shade or to be used for timber or fuel wood production. The communities in the Kgalagadi ecosystem which comprise of four affected villages of BORAVAST (Bokspits, Rapplespan, Vaalhoek and Struizendam) reported that the invasive species have led to the following: blockage of boreholes and depletion of groundwater due to the deep and extensive root system of Prosopis (Muzila et al. 2011). It is estimated that Prosopis can consume 192 million m3 of water per annum (Le Maitre et al. 2000), which translates to 1100 mm of rainfall (Walsh et al. 2016). Given that Kgalagadi District is an arid area receiving 250 mm of rainfall per annum, the amount of water used by the species is more than four times the amount of rainfall. The species is adapted to low rainfall and uses its deep tap root system of about 53 m to extract groundwater (Dzikiti et al. 2017). It lowers the water table and the ability of the already water deficient ecosystem to provide water. Lowering of the water table has also been found to alter the ecology of the invaded areas. For instance, Schachtschneider and February (2013) found that in Gannavlakte, southern Kalahari, Prosopis was responsible for an increase in mortality and dieback in Senegalia erioloba (E.Mey.) P.J.H.Hurter, a keystone species in Kgalagadi Desert. Given that the two invaded districts in Botswana (Kgalagadi and Ghanzi) are part of the Kgalagadi Desert, they are likely to face mortality of Acacia species. The affected species will no longer provide the services they used to provide, e.g. shade, timber and fuel wood.

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Table 2.3  Impact of Prosopis on ecosystem services of the Kgalagadi District Ecosystem services category Provisioning

Ecosystem impact details Example service Food

Positive impacts (i) Pods for fodder; and (ii) medicinal uses; and (iii) nectar for honey production.

Water

Timber Energy

Regulating

Cultural

Timber for furniture and construction. Charcoal and fire wood

Negative impacts Decrease in (i) rangeland productivity and grazing potential. Reduction in quality and quantity of water, and decrease in water provisioning. Decline in timber from other tree species. Decline in supply of charcoal and fire wood from other tree species.

Nutrient cycling

Enhance nitrogen input and soil fertility via nitrogen fixation. Climate (i) Sink for greenhouse gas regulation (CO2); and (ii) increase soil carbon stores Erosion control (i) Dense ground cover and deep-root system reduce soil erosion; and (ii) stands of Prosopis trees act as windbreak Biodiversity Low water table negatively impacts biodiversity; some species die while others fail to provide services Recreational Mature trees provide shade for Decrease in aesthetic value activities relaxation and entertainment of recreational areas and tourism experience Impassable thickets block Spiritual and access to places of worship religious and spiritual activities activities Cognitive Landscape tainted with effects dense stands of Prosopis may negate inspiration for architectural designs.

2.3.3.2  Regulating Services When invasive exotic species are introduced outside their native ecosystems, differences in ability to sequester carbon (C) could affect the amount of carbon released to the atmosphere (Pejchar and Mooney 2009). Different plant species show differences in their capacity to absorb, reserve and release C (Conti and Diaz 2013). Trees

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of Prosopis, as all components of vegetation, mitigate climate change through C sequestration (Patnaik et al. 2017). Invasion into savanna ecosystems by Prosopis can significantly impact ecosystem processes and influence biogeochemical cycles, C sequestration and cycling (Birhane et al. 2017) (Table 2.3). In Ethiopia, Birhane et  al. (2017) recorded significantly high total C (85.8  Mg C ha−1) stocks in sites invaded by P. juliflora than sites with no incidence of invasion (50.4 Mg C ha−1). This observation implies that Prosopis, can provide regulating service in the form of climate change mitigation, i.e. reduction in carbondioxide (CO2) from the atmosphere. Climate change is forecasted to change the amount and distribution of rainfall and such changes are likely to be severe in arid to semi-arid environments, which are already experiencing low and highly variable rainfall (Kenabatho et al. 2012). In Botswana, Parida and Moalafhi (2008) projected 2-17% decrease in rainfall quantiles with 10-year and 0-14% decrease in rainfall quantiles with 50-year occurrence. The challenges of climate change in the two arid districts of Botswana are likely to be aggravated by Prosopis invasion, especially in communal grazing areas. The dryland ecosystems are least resilient and are, therefore, expected to be hardest hit by climate change. As Mainka and Howard (2010) have highlighted, climate change is likely to worsen the impact of Prosopis on ecosystem services. 2.3.3.3  Cultural Services Cultural services are defined as non-material benefits of ecosystems (Table  2.3). Impacts of alien invasive species are difficult to determine because of their subjectivity, i.e. assessment is based on personal and local value systems (Pejchar and Mooney 2009). In Botswana, livestock farming is an important livelihood strategy for farmers in the Kgalagadi and Ghanzi District as crop farming is limited by poor sandy soils and low annual rainfall (< 250 mm). Communal grazing rangelands are, therefore, important sources of ecosystem services in these arid areas. Prosopis has invaded these grazing areas forming dense thorny impenetrable thickets that limit livestock and human movement thus undermining societal benefits from their ecosystem. The dense thickets of Prosopis along the roadsides obscure driving visibility resulting road accidents involving vehicles in hitting livestock and wild animals (BCAPR 2004). The dense stands may also limit access to recreational and spiritual areas. In Kalagadi District of Botswana, communal grazing areas were ranked the highest income generating land use in terms of non-marketed ecosystem services (Favretto et al. 2016), but Prosopis can take over grazing land and reducing rangeland productivity (Shackleton et  al. 2017). When livestock lose palatable fodder species due to invasion by Prosopis, they are moved long distances away from their area to other areas free of Prosopis (Witt 2010). However, this movement can result in conflict as the resident communities may deny the livestock grazing for fear of Prosopis spreading into their areas. The thorny bush of Prosopis may also interfere with recreational and spiritual activities. Generally, human welfare will be affected by Prosopis invasion.

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2.3.4  Salvinia molesta Mitchell (Salviniaceae) Okavango Delta, a Kalahari Oasis declared a ramsar site in 1997 and 1000th UNESCO World Heritage Site in 2014 (Darkoh and Mbaiwa 2014) presents livelihood opportunities for people. As a freshwater ecosystem, it underpins societal well-being, providing drinking water, fisheries, water purification, recreation and spiritual enrichment (MEA 2005). The communities living around the Delta derive livelihood by making use of the available natural resources such as water, land and living biological resources (Kgathi et al. 2006). Common activities in the Delta are mostly related to tourism and include fishing, boat navigation, edible aquatic plant harvesting and water supply (Kurugundla et al. 2016). However, invasion by alien invasive aquatic S. molesta negatively impacts on the supplies of these ecosystem services. It negatively impacts a wide range of ecosystem services in the Delta, including regulation (e.g. nutrient cycling and water purification), provisioning (e.g. water, food, fishing, fodder and grass) and cultural (recreational activities and spiritual fulfillment). The aquatic weed, Salvinia, originally from Brazil (Li et al. 2018), is now widespread in aquatic systems in Africa, Asia and Australia (Forno and Harley 1979). It entered Botswana via the Zambezi at Kazungula along the Chobe River in 1948 (Edwards and Thomas 1977). Salvinia is now widespread in Moremi Game Reserve, Okavango Delta and Kwando-Linyanti-Chobe River Systems (Naidu et al. 2000). Kurugundla et al. (2016) identified two factors that enhance invasion by Salvinia, lack of natural enemies outside its native range and presence of nutrient rich (nitrate and phosphate) aquatic systems associated with eutrophication. It is a free-floating aquatic fern capable of doubling its biomass in less than 5  days (Mathew et  al. 2015). This rapid growth rate confers invasiveness and enables it to cover an entire water surface within a short time (Syaichurrozi 2018). Additionally, it can reproduce vegetatively even after severe destruction or drying for long days (Thomas and Room 1986). Salvinia invasion is threat to water availability and sanitation (Goal 6) and sustainable consumption and production patterns (Goal 12). In response to the threats on ecosystem services, the Government of Botswana through the Department of Water Affairs introduced Salvinia weevil Cyrtobagous salviniae Calder and Sands for biological control of S. molesta and also the 1986 “Aquatic Weed (Control) Act” to regulate the movement and importation of boats and aquatic apparatus both within and from neighbouring countries. Despite these measures, there are cases of new infestations which are linked to fishing activities and boat/canoe movement within the Delta. 2.3.4.1  Provision Services Communities that live in close proximity to the Okavango Delta in Botswana derive benefits from this aquatic system through fishing, veld product harvesting and water for both livestock and human consumption. Common veld products harvested

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Table 2.4  Impact of Salvinia on ecosystem services of the Okavango Delta Ecosystem services category Provisioning

Ecosystem impact details Example service Food

Positive impacts New source of food for fish and fishing activities.

Water

Regulating

Water purification

Removes nitrogen, phosphorus and other nutrients from aquatic system.

Degrades the quality and quantity of litter inputs to aquatic food webs. Alter aquatic ecosystem and reduce habitat for other aquatic species such as invertebrates and fish.

Habitat

Climate regulation Light quality

Cultural

Recreation and tourism

Spiritual enhancement Cognitive effects

Negative impacts Block access to the river by dugout canoe or boat and limit access to fishing, veld products and grass harvesting grounds. Increase water loss through evapotranspiration, blocks water supply intake and limits availability of water for humans, livestock and wildlife. Increase sediment re-suspension and change state of water from clear to turbid.

Carbon sequestration through photosynthesis. Salvinia matt on water surface reduce light penetration and limit photosynthesis. Limit water-based recreational activities e.g. Viewing of water birds and other aquatic wildlife; loss of recreation and aesthetic values. Loss of water clarity for spiritual activities. Loss of inspiration for arts motivated by aquatic scenery and landscape; loss of educational opportunities from observation of aquatic wildlife.

include palm leaves (Hyphaene petersiana Klotzsch ex Mart), thatching grass species (Eragrostis pallens Hack, Aristida stipitata Hack and Cymbopogon caesius (Hochst.) Burtt Davy) and various wild fruits (Kgathi et al. 2005). Salvinia has the potential to undermine provision of these ecosystem services (Table  2.4) to both local communities and Government policy needs. Invasion by Salvinia affect provision services in the Okavango Delta and surrounding areas. Kgomotso and Swatuk (2006) found that communities within the Okavango Delta areas depend on water for resources, such fish, building and handicraft materials (Kgomotso and Swatuk 2006). Salvinia biomass has been shown by

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Kurungudla et al. (2016) to be a threat to these services as it reduces water flow in rivers, thus affects irrigation schemes and impeded flow of water from floodplains. Communities in Ngamiland who live in close proximity to the Delta complained that Salvinia invasion blocks channels and impedes water flow, leaving them with no water (Kgomotso and Swatuk 2006). In Indonesia, Syaichurrozi (2018) research has illustrated that Salvinia grows quickly within a short time to form thick impenetrable mats over the entire water surface. The impenetrable mats about 40  cm thick (Diop and Hill 2009) prevent light from reaching other aquatic plants and thus affect their survival (Mbaiwa 2003). The dense mats of Salvinia outcompeted the growth of Ludwigia stolonifera (Guill. & Perr) Raven, Leersia hexandra Swartz, Marsilea spp. and Ultricularia gibba L., U. stellaris L.f., U. foliosa L. in the Okavango Delta (Kurugundla et al. 2016). Invasion by Salvinia negatively impacts on provision of fish as an important ecosystem services. The Okavango Delta boasts about 71 fish species (Tweddle et  al. 2003) with diverse morphological characteristics (Ramberg et  al. 2006). Fish is an essential component of the diet and nutrition of the poor and vulnerable riparian communities (Mosepele and Kolawole 2017). In Ngamiland, the region that houses the Okavango Delta, 65% of the population relies on the Delta’s fishery (Mosepele 2001). The Delta provides a small-scale commercial (Mosepele and Ngwenya 2010) and subsistence fishery (Ngwenya et  al. 2012). Fish trade is, therefore, a key source of income generation and employment creation. Fish accounted for 12% of the food export in Botswana in the 2010/11 period, indicating that an increase in fish production in the country can bridge the gap between food imports and exports (Mosepele and Kolawole 2017). Invasion by Salvinia negatively impacts on provision of this important ecosystem services. Salivinia reduces dissolved oxygen levels by up to 30% (Naidu et  al. 2000) and its thick mats inhibit light penetration. These constraints reduce fish populations and communities in the delta (Mosepele et al. 2009). Over and above these constraints, dense mats of Salvinia on water surface will physically impede fishing activities, e.g. boat navigation and setting up of fish nets. 2.3.4.2  Regulating Service In the Okavango Delta water body systems, invasion by Salvinia will result in engineered ecosystems in which the Delta will now fail to provide regulatory services e.g. water filtration and nutrient cycling. Aquatic plants play a major ecological role and largely influence the composition, function and capacity of the aquatic system to provide services (O’Hare et al. 2018). They interact with and substantially change hydrological, geomorphological and physiochemical processes (Gallardo et al. 2015; Wood et al. 2017) (Table 2.4). In the Delta, aquatic plants have the ability to absorb nutrients and heavy metals through evapotranspirative concentration (Lubinda et al. 2017). The process is facilitated by floating vegetation that inhibits light penetration and temperature and, thus, limits waterloss through evatranspiration (Kadlec 1989).

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The dense mats of Salvinia on water surfaces block sunlight and inhibit photosynthesis resulting in a decrease in dissolved oxygen and pH (Chapman et al. 2017). Sculthorpe (1985) have also illustrated that Salvinia litter may also settle at the bottom of the water body and modify habitat for fish and other aquatic organisms. This is true for the Okavango inland Delta in that, Salvinia and grass communities form sudds in narrow channels have already been found to affect water flows of the Delta (Kurugundla et al. 2016). In the Okavango Delta waterbody Salvinia co-exists with about 22 other aquatic plants to form ‘deceptive islands’, which cause death of livestock and wild animals by drowning in deep water (Kurugundla et  al. 2016). In contrast to the negatives however, Salvinia molesta invasive species can also have positive outcomes which however are outweighed by the negatives that are already outlined in the preceding paragraphs. For instance, in Deinze, Belgium, salvinia has been reported to be efficient in the removal of total nitrogen and total phosphorus from aquatic systems (Vandecasteele et  al. 2005). In a study in Sri Lanka Abeywardhana et al. (2017) found Salvinia to be efficient in removal of total nitrogen and total phosphate, and heavy metals (cromium, copper, iron, nickel and lead) from waste water. This observation is presented with caution because while this is a positive impact, it is by far out-weighed by damage of Salvinia to other ecosystem services, more so in the Okavango Delta world heritage site. 2.3.4.3  Cultural Services As already outlined in introduction sections, cultural services are intangible benefits of ecosystems and closely related to aesthetic, spiritual and heritage values (Bieling and Plieninger 2013; Table  2.4) and are usually valued by the individuals that receives them during their interaction with biodiversity (McGinlay et al. 2018). The water in the Okavango Delta is used for various cultural activities that provide ceremonial, recreational (swimming); transport (boat ride) and religions (baptism) services. Invasion by Salvinia has the potential to limit or inhibit these cultural activities. As Salvinia reduce certain water-body services, it is likely to motivate relocation of people into other areas that are not affected. This is likely to cause conflict among the different communities as competition for ecosystem services offered by the Okavango Delta intensifies. In addition, Dense mats of Salvinia on water surfaces affect the physical appearance and recreational value of the Delta. Heavy infestation of water bodies will affect swimming and recreational fishing activities. Diseases  Salvinia may also serve as a habitat for insects, e.g. mosquito vectors that cause malaria (Oliver 1993). Malaria is already a public health concern in Botswana (Motlaleng et  al. 2018) and is endemic in the Okavango Delta (Maphane et  al. 2017). Salvinia invasion is, therefore, likely to worsen the malaria problem. Impact on Economic Development  The recreational activities and wildlife biodiversity within the Delta are the main important attraction for tourism, the second

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most important economic activity in Botswana after diamonds (Mbaiwa 2002). The presence of Salvinia in the Delta system will degrade its aesthetic value and limit recreational activities. Tourists may be offended by the Delta scenery and landscape tainted with floating mats of Salvinia. For instance, in 1986, 1992, 1998 and 2010, thick coverage of Salvinia in tourist spots (mostly lagoons) affected tourism activities, including photographic activities (Kurugundla et al. 2016). Additionally, the Delta in such a condition may not inspire artistic creativity, i.e. architectural designs inspired by aquatic biodiversity and landscape. Clearly, Salvinia invasion will negatively impact cultural ecosystem services.

2.4  Conclusions and Policy Recommendations This review carried out on Prosopis and Salvinia highlights the impacts of invasive plant species on ecosystem services and biodiversity of two ecosystems in Botswana, being the Kgalagadi and Okavango Delta. It has demonstrated that invasion by the two species in the respective ecosystems threaten achievement of SDG by Botswana in that SDG 15 (protecting ecosystems and forests) is threatened in the case of Kgalagadi; and SDG 6 (water availability) is threatened in the case of the Okavango Delta world heritage site. Biodiversity and ecosystem services play a critical role in achievement of SDGs. Therefore, the two case studies illustrate that there is a need to relate biodiversity to the SDGs in order to achieve sustainable environmental development. An assessment of both species has revealed that they have the potential to limit the ability of the resident ecosystems to provide services and societal benefits, thereof, of such services. Developing more knowledge about the impact of invasive species on ecosystem services through research is the first step in formulating effective practices and policy framework for invasive species management. It also forms the basis for determining the level of prevention and mitigation responses to protect or maintain a service under threat. There is a need for species-specific plans and strategies to deal with specific invasions. Other strategies may involve designing the management plan for plants with similar impacts and pathways of introduction. Most of all, the management plans and strategies should be supported by policy and legal framework. The case of Prosopis in south-western Botswana demonstrates how innovation with good intentions can result in unintended consequences as it outlines how Prosopis was introduced to Botswana as an ecosystem engineer to control soil erosion and stabilize sand dunes. However, it became invasive and resulted in negative impacts on supply of provisioning ecosystem services. The affected communities in the BORAVAST area indicated that sand dune stabilization, as an ecosystem service, has been positively impacted by the introduction of Prosopis and, therefore, are against complete eradication of the plant. Based on the observation provided by case study of Prosopis in Botswana, it is recommended that the decisions on whether or not to retain this novel ecosystem

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should only be adopted when the goods and services provided by Prosopis far outweigh the costs of its containment and management. Therefore, the negative impacts of Prosopis on ecosystem services and human well-being should be minimized, while maintaining some benefits (provisioning and regulating services) where justified and attainable. Given its ecology and biology of Prosopis, it would be difficult to stop it from spreading into adjacent ecosystems. The aquatic weed, Salvinia has invaded the aquatic system in the Okavango Delta and is negatively impacting on ecosystem services and biodiversity. It has resulted in negative impacts on the supply of provisioning ecosystem services (edible aquatic plants, fishing and boat navigation). Other ecosystem services negatively impacted include regulation (water filtration and nutrient cycling) and cultural (recreational activities and spiritual fulfillment). Invasion by Salvinia is likely to disrupt the tourism industry, a key source of employment creation and income generation in the Okavango Delta. Salvinia continues to spread to new areas within the Delta despite implementation of the control measures. It is, therefore, recommended that the Okavango Delta should be zoned for fishing activities to regulate movement of fishing apparatus from one area to another. Given its high biomass production rate, the potential of this biomass as plant compost and in biogas production should be explored. In summary, it is recommended that Botswana should start to base risk assessment of invasive species not only on species’ ecological and economic impacts, but also on effects on the capacity of an ecosystem to provide services and achieve SDG 2 (food security), 6 (water availability) and 12 (sustainable consumption and production patterns). In addition, ecosystem services should be valued in monetary terms and integrated into decision making framework regarding species invasion. Such an assessment will be cognizant of the return on investments in management and control of invasive plant species as benefits to social welfare and the economy. Finally, an attempt should be made to ensure that all alien plants proposed for introduction to Botswana should be subjected to risk assessment to determine their invasiveness potential before they can be accepted for introduction to Botswana. Acknowledgement  The authors would like to thank Okavango Research Institute through its GIS technician, Mrs. A. Makati for designing map of the study areas in Fig. 2.1.

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Chapter 3

Nutrients in a Changing Environment: Implications on the Sustainability of the Okavango Delta Oarabile Mogobe, Bernice Setomba, and Wellington R. L. Masamba

Abstract  The sustainability and integrity of riverine ecosystems depend partly on the balance between environmental requirements and the socio-economic developmental needs of a country. Scientific data can provide a critical foresight into the possible impacts on environment, brought about by natural geologic processes, land-use activities and climate change. Developmental changes in the shared Cubango/Okavango River basin are increasing, posing risk to the long term integrity of one of Africa’s Ramsar site housing rich biological diversity and Botswana’s tourism pride. Scientists have shown that the Okavango delta is an oligotrophic system, reflecting low levels of nutrients in surface waters and this state is critical for the sustainability of the delta. This study assessed the spatial and temporal variations of inorganic nitrates and phosphates species within the Okavango Delta to evaluate possible impact of reported land use changes on surface water quality and sustainability of the Okavango delta. The study was conducted over 3 years, from 2014–2017, covering a total of seven sites; four in the upper delta and three in the lower delta. Concentrations of NO3-N and PO4-P were measured monthly at Mohembo, Sepopa, Etsatsa, Xakanaka, Khwai, Maun and Lake Ngami in the Okavango delta. The results show nitrate concentrations ranging from below detection limit to 12.72  mg/L and 9.72  mg/L at high and low flows respectively. Phosphates on the other hand, ranged from below detection limit to 1.26 and 0.50 mg/L at high and low floods respectively. The mean concentrations of these inorganic nutrients were relatively low in the upper delta (Mohembo to Xakanaka) and increased downstream at Khwai, Maun and Lake Ngami, probably due to evapo-concentration and nutrient loadings from livestock because animals have direct access to the river. Only two sites, Khwai and Lake Ngami, had nitrate concentrations which were above the US EPA and the South African guideline for O. Mogobe (*) · B. Setomba Okavango Research Institute, University of Botswana, Maun, Botswana e-mail: [email protected] W. R. L. Masamba Botswana International University of Science and Technology, Palapye, Botswana © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020 S. O. Keitumetse et al. (eds.), Sustainability in Developing Countries, https://doi.org/10.1007/978-3-030-48351-7_3

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aquatic ecosystems value of 0.5 mg/L. Phosphate concentrations at all study sites were well below the South African guideline of