Invading Nature Springer Series in Invasion Ecology 14 Brian W. van Wilgen · John Measey David M. Richardson · John R. Wilson Tsungai A. Zengeya Editors Biological Invasions in South Africa Invading Nature - Springer Series in Invasion Ecology Volume 14 Series Editor Daniel Simberloff Department of Ecology and Evolutionary Biology University of Tennessee Knoxville, TN, USA Biological Invasions represent one of those rare themes that cut across the disciplines of academic biology, while having profound environmental, philosophical, socio- economic, and legislative implications at a global scale. There can be no doubt that biological invasions represent the single greatest threat to biodiversity past the activities of humankind itself. The implications are far reaching. Novel ecological and evolutionary forces are now directing the future expression of life itself, as native species and the communities that they comprise contend with invading species. The rules of the game have been suddenly and irrevocably changed. Invading Nature - Springer Series in Invasion Ecology is a new book series topically spanning the breadth of invasion biology. The series is of singular importance as an integrative venue focusing on the broader ecological and evolutionary issues arising from non-native species, the impacts such species have in particular environs, trends patterns and processes, as well as causes and correctives. The series seeks novel and synthetic approaches to invasions including experimental, theoretical, systematic and conceptual treatments. Prospective authors and/or editors should consult the Series Editor Daniel Simberloff for more details: e-mail: tebo@utk.edu More information about this series at http://www.springer.com/series/7228 Brian W. van Wilgen • John Measey • David M. Richardson • John R. Wilson • Tsungai A. Zengeya Editors Biological Invasions in South Africa Editors Brian W. van Wilgen Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Stellenbosch, South Africa John Measey Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Stellenbosch, South Africa David M. Richardson Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Stellenbosch, South Africa John R. Wilson South African National Biodiversity Institute, Kirstenbosch Research Centre Cape Town, South Africa Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University Stellenbosch, South Africa Tsungai A. Zengeya South African National Biodiversity Institute, Kirstenbosch Research Centre Cape Town, South Africa Centre for Invasion Biology, Department of Zoology and Entomology, University of Pretoria Pretoria, South Africa Invading Nature - Springer Series in Invasion Ecology ISBN 978-3-030-32393-6 ISBN 978-3-030-32394-3 (eBook) https://doi.org/10.1007/978-3-030-32394-3 This book is an open access publication. © The Editor(s) (if applicable) and The Author(s) 2020 Open Access This book is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence and indicate if changes were made. The images or other third party material in this book are included in the book ’ s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the book ’ s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a speci fi c 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 af fi liations. This Springer imprint is published by the registered company Springer Nature Switzerland AG. The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Foreword South Africa has played an outsize role in the history of biological invasions and the development of an invasion science to understand and mitigate their impacts. Containing a large region with temperate climate, South Africa, beginning with European colonisation in the seventeenth century, joined Australia, New Zealand, many oceanic islands, and large parts of the Americas as a victim of what historian Alfred Crosby termed “ ecological imperialism, the biological expansion of Europe. ” Besieged by terrestrial, freshwater, and marine species purposely or accidentally introduced, South Africans perhaps fi rst perceived that such newly arrived species could be problematic in 1713 when smallpox arrived in Cape Town, killing many indigenous Khoikhoi, who attributed the introduction to the Dutch. European immi- grants and their descendants, by and large, welcomed — indeed, deliberately intro- duced — many of the new additions to the biota, especially trees in the South African ecosystems lacking forests — savanna, grassland, and fynbos. Trees provided wood, fruit, and shelter and were an aesthetic amenity attractive to European settlers. By the turn of the twentieth century, some of these widely established nonnative species, especially plants, were recognised as problematic. Northern hemisphere conifers were fi rst recorded as invasive in 1855, European spiny burweed by 1860, Australian blue gum by the late 1860s, and Australian acacias by the turn of the century. This was also when the advantages of New World prickly pear as edible fruit and fodder were fi nally seen by many as outweighed by their disadvantages in destroying pasture and harming livestock. Thus began the South African attempt to understand the biology behind these invasions and to defeat them. Biological control projects to control both insect and plant pests were quickly initiated: the vedalia beetle from Australia was introduced in 1892 to attack the Australian cottony cushion scale and the American cochineal insect was released in 1913 to attack prickly pear. In the early twentieth century, many lady beetles were also introduced to control insect pests, but with little success. Thus began the growth of an increas- ingly sophisticated South African science of biological control tailoring projects to complex problems such as limiting spread of plants that are valued in some settings (e.g., for timber or food) but reviled when they invade other sites, such as pastures or v natural areas. In light of a good number of successes, South Africa is now recognised as a world leader in plant biological control. The initial impetus for the international program of SCOPE (Scienti fi c Committee on Problems of the Environment) that began modern invasion science came from a SCOPE workshop held in 1980 at Hermanus, South Africa, on the ecology and conservation of Mediterranean-type ecosystems. Discussions at the workshop led to a proposal to the SCOPE governing board in 1982 that was approved and led to a decade-long program of workshops with hundreds of participants throughout the world (including one workshop in South Africa). This program produced fi ve books, two journal special issues, and many other papers. South African scientists were heavily involved in the SCOPE program from the start, and 5 of the 22 authors of the synthesis volume published in 1989 were South African. Of the fi ve SCOPE books, only the South African one — The Ecology and Management of Biological Invasions in Southern Africa — fully addressed the stated SCOPE project goal of applying scienti fi c knowledge to solving environmental problems, with 11 of its 25 chapters dealing with management. The other SCOPE products dealt almost exclusively with the academic question of why some species become invasive upon introduction to new areas and others do not or were largely depictions of ecological impacts of particular invasions. This focus of the South African volume on integrating science with management has been a continuing hallmark of South African invasion science that contrasts with the rather separate academic and applied endeavors in other nations leading invasion research — the USA, Australia, and New Zealand. The South African Working for Water program initiated in 1995 immediately attracted global attention and excitement as the largest public works program ever conceived to tackle plant invasions, thereby aiding biodiversity and water conser- vation and at the same time addressing poverty by creating jobs and developing human skills. Its continuing evolution and innovation with a mix of biological control, chemical control, and mechanical or manual control is of utmost interest as not only South Africa but other nations worldwide cope with similar problems, often involving the same invasive plants that besiege South Africa. The Centre for Invasion Biology, established in 2004 as a network housed at Stellenbosch Univer- sity but with associated scientists and students throughout the country, is a unique organisation that is widely admired as an enormously productive locus of research and training on mechanisms, impacts, and management of invasions and an inter- national hub of in fl uential discussions on invasion science and policy. The hundreds of papers published annually under the Centre ’ s imprimatur in leading international journals epitomise a long tradition in South African invasion science — a plethora of books, journal articles, and widely distributed reports from universities and govern- ment agencies that have placed South Africa in the forefront of research to under- stand, manage, and adapt to one of the great global changes transforming all ecosystems and affecting the human societies that depend on them. Along with the wealth of invaders and the strong attempt to cope with them that has increasingly developed over the past few decades have also come innumerable con fl icts and controversies, often of the sorts that beset other nations. Thus, South Africa has invasive plants that are ecologically damaging yet beloved by the vi Foreword public — Pretoria ’ s famous South American jacaranda trees are a prime example. It has nonnative salmonids that threaten native fi shes but are prized by anglers who challenge legislative efforts to limit invasion. It has critics from within and outside of South Africa, mostly from the social sciences or humanities, who ignore or down- play invasion impacts on native species and ecosystems and depict the entire enterprise of managing nonnative species as a manifestation of xenophobia or even a legacy of apartheid. All of these socio-ecological problems concerning policy and management of invasive nonnative species have analogs elsewhere, and South Africa ’ s extensive history of dealing with such issues may help guide other nations in their efforts to resolve similar controversies. Finally, it is important to recognise that the major part of the growth of a sophisticated invasion science in South Africa has occurred since the abolition of apartheid and fi rst universal elections in 1994. Thus, this ambitious effort has occurred in the context of a radical change in governance and a monumental struggle to erase the poverty of the majority of its citizens. The initiation of Working for Water and the extensive educational and outreach programs of the Centre for Invasion Biology are striking manifestations of the dual urgent objectives South Africa has set for itself, and the challenges faced by other nations leading the growth of modern invasion science pale in comparison. In light of the long history of biological invasions in South Africa, its leading role in confronting them in a dif fi cult and complex sociopolitical context, and its large corps of scientists who have devoted their lives to understanding their impacts and how to address them, it is exciting that all aspects of the issue are now summarised in Biological Invasions in South Africa . We owe the editors and authors our gratitude for presenting their insights. The lessons from South Africa inspire some optimism that, with appropriate willpower and effort, invasions are one signi fi cant global change that can be contained and partially redressed without the massive, irrevocable damage to native biodiversity and ecosystems that has characterised much of the global picture. University of Tennessee Knoxville, TN, USA Daniel Simberloff Foreword vii Acknowledgments The editors would like to thank all the contributing authors for their hard work and insights and especially those who met the deadlines. We are also grateful to our colleagues from around the globe who gave their time to review drafts of chapters contained in this book: Andrew Turner, Angus Paterson, Anna Travaset, Arne Witt, Bob Scholes, Brett Bennett, Brett Hurley, Brian Huntley, Carrie Brown-Lima, Celeste Franceschini, Charles Grif fi ths, Dane Panetta, Darragh Woodford, David Le Maitre, Errol Douwes, Fabián Jaksic, Franz Essl, George Branch, Gillian Key, Graham Jewitt, Grant Martin, Guillaume Latombe, Harry Biggs, Helen Roy, Ingo Kowarik, James Aronson, James Cuda, Jan Pergl, Jane Carruthers, Jeremy Midgley, John Cooper, John Hargrove, John Terblanche, Julie Lockwood, Klaudia Schachtschneider, Laura Meyerson, Lesley Le Grange, Libby Robin, Marcus Byrne, Michael Cheek, Mike Meadows, Nick Mandrak, Nicky Allsopp, Oliver Ruppel, Patricia Holmes, Paul Skelton, Peter Lukey, Peter Novelie, Phill Cassey, Piero Genovesi, Pieter Winter, Quentin Paynter, Reuben Keller, Richard Shaw, Rob Crystal-Ornelas, Robin Drennan, Roy Bengis, Rui Rebelo, Sally Archibald, Sarel Cilliers, Sue Milton, Sven Bacher, Terence Olckers, Tim Adriaens, Timm Hoffman, Tony Grice, Tony Ricciardi, Wayne Dawson, and William Bond. Llewellyn Foxcroft arranged for accommodation and logistical support for an editor ’ s writing retreat in March/April 2019 in Skukuza, Kruger National Park, and we thank him for this opportunity to focus on our work in tranquil and uninvaded surroundings. We would also like to thank Susan Abrahams who redrafted most of the illustrations in this book, and Jonathan Plaistowe who assisted in obtaining the neces- sary copyright waivers for material that had previously been published elsewhere, as well as with the compilation of the taxonomic index. Administrative staff at the Centre for Invasion Biology at Stellenbosch University provided us with support in many ways during the rather long gestation period of this book, and we are grateful to them for always being helpful and friendly. Alexandrine Cheronet from Springer ably attended to many queries during the preparation of this book. We also thank Daniel Simberloff for writing the Foreword. Finally, we thank the DSI-NRF Centre for Invasion Biology and the National Research Foundation, South Africa, for fi nancial support (Grants: BvW: 109467; DMR: 85417; JM: 87759; JRW: 119521; TAZ: 103603), and the South ix African Department of Environment, Forestry, and Fisheries (DEFF) for funding the South African National Biodiversity Institute noting that this publication does not necessarily represent the views or opinions of DEFF or its employees. The editors at an editorial workshop in April 2019 at Skukuza, Kruger National Park. Standing, from left to right: John Wilson, Brian van Wilgen, Dave Richardson, John Measey, and Tsungai Zengeya x Acknowledgments Contents Part I Background 1 Biological Invasions in South Africa: An Overview . . . . . . . . . . . . . 3 Brian W. van Wilgen, John Measey, David M. Richardson, John R. Wilson, and Tsungai A. Zengeya 2 A Brief, Selective History of Researchers and Research Initiatives Related to Biological Invasions in South Africa . . . . . . . . 33 Brian W. van Wilgen Part II Biological Invasions in South Africa 3 The Biogeography of South African Terrestrial Plant Invasions . . . 67 David M. Richardson, Llewellyn C. Foxcroft, Guillaume Latombe, David C. Le Maitre, Mathieu Rouget, and John R. Wilson 4 Invasive Alien Aquatic Plants in South African Freshwater Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Martin P. Hill, Julie A. Coetzee, Grant D. Martin, Rosali Smith, and Emily F. Strange 5 Terrestrial Vertebrate Invasions in South Africa . . . . . . . . . . . . . . . 115 John Measey, Cang Hui, and Michael J. Somers 6 Alien Freshwater Fauna in South Africa . . . . . . . . . . . . . . . . . . . . . 153 Olaf L. F. Weyl, Bruce R. Ellender, Ryan J. Wassermann, Marliese Truter, Tatenda Dalu, Tsungai A. Zengeya, and Nico J. Smit 7 Alien Terrestrial Invertebrates in South Africa . . . . . . . . . . . . . . . . 185 Charlene Janion-Scheepers and Charles L. Grif fi ths xi 8 Biological Invasions in South Africa ’ s Offshore Sub-Antarctic Territories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Michelle Greve, Charles Eric Otto von der Meden, and Charlene Janion-Scheepers 9 Coastal Invasions: The South African Context . . . . . . . . . . . . . . . . 229 Tamara B. Robinson, Koebraa Peters, and Ben Brooker 10 Pathogens of Vertebrate Animals as Invasive Species: Insights from South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 Lesley van Helden, Paul D. van Helden, and Christina Meiring 11 Biological Invasions in South Africa ’ s Urban Ecosystems: Patterns, Processes, Impacts, and Management . . . . . . . . . . . . . . . . . . . . . . . 275 Luke J. Potgieter, Errol Douwes, Mirijam Gaertner, John Measey, Trudy Paap, and David M. Richardson Part III Drivers of Invasion 12 South Africa ’ s Pathways of Introduction and Dispersal and How They Have Changed Over Time . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Katelyn T. Faulkner, Amy Burness, Marcus J. Byrne, Sabrina Kumschick, Koebraa Peters, Mark P. Robertson, Davina L. Saccaggi, Olaf L. F. Weyl, and Vivienne L. Williams 13 The Role of Environmental Factors in Promoting and Limiting Biological Invasions in South Africa . . . . . . . . . . . . . . . . . . . . . . . . 355 John R. Wilson, Llewellyn C. Foxcroft, Sjirk Geerts, M. Timm Hoffman, Sandra MacFadyen, John Measey, Anthony Mills, David M. Richardson, Mark P. Robertson, and Brian W. van Wilgen 14 Biotic Interactions as Mediators of Biological Invasions: Insights from South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 Johannes J. Le Roux, Susana Clusella-Trullas, Thabiso M. Mokotjomela, Mario Mairal, David M. Richardson, Lisa Skein, John R. Wilson, Olaf L. F. Weyl, and Sjirk Geerts Part IV Impacts of Invasion 15 Impacts of Plant Invasions on Terrestrial Water Flows in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 David C. Le Maitre, James N. Blignaut, Alistair Clulow, Sebinasi Dzikiti, Colin S. Everson, André H. M. Görgens, and Mark B. Gush 16 The Impact of Invasive Alien Plants on Rangelands in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 Timothy G. O ’ Connor and Brian W. van Wilgen xii Contents 17 An Evaluation of the Impacts of Alien Species on Biodiversity in South Africa Using Different Assessment Methods . . . . . . . . . . . 489 Tsungai A. Zengeya, Sabrina Kumschick, Olaf L. F. Weyl, and Brian W. van Wilgen Part V Management of Invasions 18 Biological Invasion Policy and Legislation Development and Implementation in South Africa . . . . . . . . . . . . . . . . . . . . . . . . 515 Peter Lukey and Jenny Hall 19 More than a Century of Biological Control Against Invasive Alien Plants in South Africa: A Synoptic View of What Has Been Accomplished . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553 Martin P. Hill, Vincent C. Moran, John H. Hoffmann, Stefan Neser, Helmuth G. Zimmermann, David O. Simelane, Hildegard Klein, Costas Zachariades, Alan R. Wood, Marcus J. Byrne, Iain D. Paterson, Grant D. Martin, and Julie A. Coetzee 20 Analysing the Risks Posed by Biological Invasions to South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573 Sabrina Kumschick, Llewellyn C. Foxcroft, and John R. Wilson 21 The Extent and Effectiveness of Alien Plant Control Projects in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597 Brian W. van Wilgen, John R. Wilson, Andrew Wannenburgh, and Llewellyn C. Foxcroft 22 Experience and Lessons from Alien and Invasive Animal Control Projects in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . 629 Sarah J. Davies, Martine S. Jordaan, Minette Karsten, John S. Terblanche, Andrew A. Turner, Nicola J. van Wilgen, Ruan Veldtman, Tsungai A. Zengeya, and John Measey 23 Biological Invasions and Ecological Restoration in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665 Patricia M. Holmes, Karen J. Esler, Mirijam Gaertner, Sjirk Geerts, Stuart A. Hall, Mlungele M. Nsikani, David M. Richardson, and Sheunesu Ruwanza 24 The Social Dimensions of Biological Invasions in South Africa . . . . 701 Ross T. Shackleton, Ana Novoa, Charlie M. Shackleton, and Christian A. Kull 25 Education, Training and Capacity-Building in the Field of Biological Invasions in South Africa . . . . . . . . . . . . . . . . . . . . . . 731 Marcus J. Byrne, Dorette du Plessis, Philip J. Ivey, John Measey, Mark P. Robertson, Tamara B. Robinson, and Kim N. Weaver Contents xiii Part VI New Insights 26 South Africa as a Donor of Naturalised and Invasive Plants to Other Parts of the World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 759 Petr Py š ek, Jan Pergl, Mark van Kleunen, Wayne Dawson, Franz Essl, Holger Kreft, Patrick Weigelt, John R. Wilson, Marten Winter, and David M. Richardson 27 South Africa as a Donor of Alien Animals . . . . . . . . . . . . . . . . . . . . 787 John Measey, Tamara B. Robinson, Natasha Kruger, Tsungai A. Zengeya, and Brett P. Hurley 28 Knowing-Doing Continuum or Knowing-Doing Gap? Information Flow Between Researchers and Managers of Biological Invasions in South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831 Llewellyn C. Foxcroft, Brian W. van Wilgen, Brent Abrahams, Karen J. Esler, and Andrew Wannenburgh 29 Biological Invasions as a Component of South Africa ’ s Global Change Research Effort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 Nicola J. van Wilgen, Brian W. van Wilgen, and Guy F. Midgley 30 South Africa ’ s Centre for Invasion Biology: An Experiment in Invasion Science for Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . 879 David M. Richardson, Brent Abrahams, Nelius Boshoff, Sarah J. Davies, John Measey, and Brian W. van Wilgen Part VII The Way Forward 31 Potential Futures of Biological Invasions in South Africa . . . . . . . . 917 John R. Wilson, John Measey, David M. Richardson, Brian W. van Wilgen, and Tsungai A. Zengeya Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 947 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 955 General Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 957 Taxonomic Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 965 xiv Contents Contributors Brent Abrahams Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa James N. Blignaut South African Environmental Observation Network, Pretoria, South Africa School of Public Leadership, Stellenbosch University, Stellenbosch, South Africa Nelius Boshoff DSI-NRF Centre of Excellence in Scientometrics and Science, Technology and Innovation Policy, Stellenbosch University, Stellenbosch, South Africa Ben Brooker Department of Biological Sciences, University of Cape Town, Cape Town, South Africa School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa Amy Burness School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa South African National Biodiversity Institute, Pretoria, South Africa Marcus J. Byrne Centre for Invasion Biology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa Centre for Biological Control, Rhodes University, Makhanda, South Africa Alistair Clulow Centre for Water Resource Research, Department of Botany and Zoology, University of KwaZulu-Natal, Pietermaritzburg, South Africa Susana Clusella-Trullas Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Julie A. Coetzee Centre for Biological Control, Department of Botany, Rhodes University, Makhanda, South Africa xv Tatenda Dalu Department of Ecology and Resource Management, University of Venda, Thohoyandou, South Africa South African Institute for Aquatic Biodiversity, Makhanda, South Africa Sarah J. Davies Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Wayne Dawson Department of Biosciences, Durham University, Durham, UK Errol Douwes Environmental Planning and Climate Protection Department, eThekwini Municipality, eThekwini, South Africa School of Life Sciences, University of KwaZulu-Natal, KwaZulu-Natal, South Africa Dorette du Plessis Centre for Invasion Biology, Department of Botany and Zool- ogy, Stellenbosch University, Stellenbosch, South Africa Sebinasi Dzikiti Natural Resources and the Environment, Council for Scienti fi c and Industrial Research, Stellenbosch, South Africa Bruce R. Ellender South African Institute for Aquatic Biodiversity, Makhanda, South Africa World Wide Fund for Nature Zambia, Lusaka, Zambia Karen J. Esler Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa Franz Essl Division of Conservation Biology, Vegetation and Landscape Ecology, University of Vienna, Vienna, Austria Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Colin S. Everson Centre for Water Resource Research, Department of Botany and Zoology, University of KwaZulu-Natal, KwaZulu-Natal, South Africa Katelyn T. Faulkner Centre for Invasion Biology, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa South African National Biodiversity Institute, Pretoria, South Africa Llewellyn C. Foxcroft Conservation Services, South African National Parks, Skukuza, South Africa Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Mirijam Gaertner Nürtingen-Geislingen University of Applied Sciences, Nürtingen, Germany Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa xvi Contributors Sjirk Geerts Centre for Invasion Biology, Department of Conservation and Marine Sciences, Cape Peninsula University of Technology, Cape Town, South Africa André H. M. Görgens Aurecon, Century City, Cape Town, South Africa Michelle Greve Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa Charles L. Grif fi ths Centre for Invasion Biology, Department of Biological Sci- ences, University of Cape Town, Cape Town, South Africa Mark B. Gush Natural Resources and the Environment, Council for Scienti fi c and Industrial Research, Stellenbosch, South Africa Jenny Hall University of Johannesburg, Johannesburg, South Africa Stuart A. Hall Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa Martin P. Hill Centre for Biological Control, Department of Zoology and Ento- mology, Rhodes University, Makhanda, South Africa M. Timm Hoffman Plant Conservation Unit, Department of Biological Sciences, University of Cape Town, Cape Town, South Africa John H. Hoffmann Department of Biological Sciences, University of Cape Town, Cape Town, South Africa Patricia M. Holmes Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa Cang Hui Centre for Invasion Biology, Department of Mathematical Sciences, Stellenbosch University, Stellenbosch, South Africa Brett P. Hurley Forestry and Agricultural Biotechnology Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa Philip J. Ivey Centre for Biological Control, Rhodes University, Makhanda, South Africa Charlene Janion-Scheepers Centre for Invasion Biology, Iziko Museums of South Africa, Cape Town, South Africa Martine Jordaan CapeNature Biodiversity Capabilities Directorate, Cape Town, South Africa Centre for Invasion Biology, South African Institute for Aquatic Biodiversity, Makhanda, South Africa Minette Karsten Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa Hildegard Klein Plant Health and Protection, Agricultural Research Council, Pretoria, South Africa Contributors xvii Holger Kreft Biodiversity, Macroecology and Biogeography, University of Göttingen, Göttingen, Germany Natasha Kruger Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Christian A. Kull Institute of Geography and Sustainability, University of Lausanne, Lausanne, Switzerland Sabrina Kumschick Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa South African National Biodiversity Institute, Kirstenbosch Research Centre, Cape Town, South Africa Guillaume Latombe Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Centre for Invasion Biology, Department of Mathematical Sciences, Stellenbosch University, Stellenbosch, South Africa Division for Conservation Biology, Vegetation and Landscape Ecology, University of Vienna, Vienna, Austria David C. Le Maitre Centre for Invasion Biology, Natural Resources and the Environment, Council for Scienti fi c and Industrial Research, Stellenbosch, South Africa Johannes J. Le Roux Department of Biological Sciences, Macquarie University, Sydney, Australia Peter Lukey Department of Environment, Forestry and Fisheries, Pretoria, South Africa Sandra MacFadyen Department of Mathematical Science, Stellenbosch Univer- sity, Stellenbosch, South Africa Mario Mairal Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Grant D. Martin Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa John Measey Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Christina Meiring DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa xviii Contributors Guy F. Midgley Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Anthony J. Mills Department of Soil Science, Stellenbosch University, Stellen- bosch, South Africa Thabiso M. Mokotjomela Centre for Invasion Biology, Operations Department, Scienti fi c Service Unit, Eastern Cape Parks and Tourism, Eastern Cape Province Agency, East London, South Africa Centre for Invasion Biology, South African National Biodiversity Institute, Free State National Botanical Gardens, Bloemfontein, South Africa Vincent C. Moran Department of Biological Sciences, University of Cape Town, Cape Town, South Africa Stefan Neser Plant Health and Protection, Agricultural Research Council, Pretoria, South Africa Ana Novoa Department of Invasion Ecology, Institute of Botany, The Czech Academy of Sciences, Pr ů honice, Czech Republic Mlungele M. Nsikani Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Timothy G. O ’ Connor South African Environmental Observation Network, Pietermaritzburg, South Africa Trudy Paap Forestry and Agricultural Biotechnology Institute, Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa South African National Biodiversity Institute, Pretoria, South Africa Iain D. Paterson Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa Jan Pergl Department of Invasion Ecology, Institute of Botany, Czech Academy of Sciences, Pr ů honice, Czech Republic Koebraa Peters Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Luke J. Potgieter Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Petr Py š ek Department of Invasion Ecology, Institute of Botany, Czech Academy of Sciences, Pr ů honice, Czech Republic Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Contributors xix David M. Richardson Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Mark P. Robertson Centre for Invasion Biology, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa Tamara B. Robinson Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Mathieu Rouget UMR PVBMT, CIRAD, La Réunion, France Sheunesu Ruwanza Centre for Invasion Biology, Department of Environmental Science, Rhodes University, Makhanda, South Africa Davina L. Saccaggi Plant Health Diagnostic Services, Directorate: Inspection Services, Department of Agriculture, Land Reform and Rural Development, Stel- lenbosch, South Africa Charlie M. Shackleton Department of Environmental Science, Rhodes University, Makhanda, South Africa Ross T. Shackleton Institute of Geography and Sustainability, University of Lausanne, Lausanne, Switzerland Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa David O. Simelane Plant Health and Protection, Agricultural Research Council, Pretoria, South Africa Lisa Skein Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa Nico J. Smit Water Research Group, Unit for Environmental Sciences and Man- agement, North-West University, Potchefstroom, South Africa Rosali Smith Centre for Biological Control, Department of Zoology and Entomol- ogy, Rhodes University, Makhanda, South Africa Michael J. Somers Centre for Invasion Biology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa Emily F. Strange Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa John S. Terblanche Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa Marliese Truter South African Institute for Aquatic Biodiversity, Makhanda, South Africa Water Research Group, Unit for Environmental Sciences and Management, North- West University, Potchefstroom, South Africa xx Contributors