John R Wilson

John R Wilson
South African National Biodiversity Institute

PhD

About

268
Publications
177,673
Reads
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18,002
Citations
Additional affiliations
May 2009 - present
South African National Biodiversity Institute
Position
  • Science Lead
April 2017 - present
Stellenbosch University
Position
  • Professor
Education
January 1999 - September 2002
Independent Researcher
Independent Researcher
Field of study
  • Biology

Publications

Publications (268)
Article
Full-text available
Colocasia esculenta (taro), native to tropical Southeast Asia, is an emergent aquatic plant with a wide global distribution. Valued for its agricultural, horticultural, medicinal, and cultural uses, it also has become invasive in some places, spreading unaided along slow-flowing water courses through corm division. Colocasia esculenta was introduce...
Data
Yitbarek, T. W., Wilson, J. R. U., & Dehnen-Schmutz, K. (2025). Investigating tree planting in Ethiopia and the extent to which scheme implementation aligns with good governance practices. Journal of Environmental Management, 373, 123475. https://doi.org/10.1016/j.jenvman.2024.123475 I used a remote sensing approach to assess how vegetation cover...
Article
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Invasive plant taxa are generally regulated at the species level, without considering infra- or inter-specific variation. However, cultivars or hybrids can be of a lower level of risk, e.g., due to sterility. We evaluate six general approaches to regulating cultivars and hybrids -1) “Globally guilty by association”; 2) “Nationally guilty by associa...
Article
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Estimates of the cost of damage caused by invasive alien speices and the money spent addressing biological invasions are needed to guide policy and management. Here, we quantify the known monetary costs of biological invasions to South Africa, using data from the InvaCost database, literature searches, and stakeholders. The Department of Forestry,...
Article
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A large number of non‐native trees (NNTs) have been introduced globally and widely planted, contributing significantly to the world's economy. Although some of these species present a limited risk of spreading beyond their planting sites, a growing number of NNTs are spreading and becoming invasive leading to diverse negative impacts on biodiversit...
Article
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Although invasive alien species have long been recognized as a major threat to nature and people, until now there has been no comprehensive global review of the status, trends, drivers, impacts, management and governance challenges of biological invasions. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)...
Article
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A key global change challenge is to significantly reduce the risks of alien taxa causing harmful impacts without compromising the rights of citizens. As part of efforts to address this challenge, South Africa promulgated comprehensive regulations and lists of alien taxa in 2014. In this paper, we review how the lists developed, changed over time, a...
Preprint
Conservation decisions often need to integrate scientific predictions with societal values, ethical systems, and diverse perceptions that combine to form moral stances about conservation actions (e.g., trophy hunting or controlling invasive species). These can result in dilemmas and, if stakeholders hold different views on the morality of particula...
Data
Around the world, billions of dollars are spent each year on tree planting schemes to address environmental, social, and economic issues. However, tree planting schemes in Africa often fail to deliver sustainable outcomes. Studies have assessed technical, ecological, and governance issues that influence the success of tree planting schemes and have...
Data
Tree planting schemes are implemented to achieve social, cultural, economic, and environmental goals. There have been multiple good governance practices to aid the achievement of these goals. However, the monitoring and reporting of tree planting schemes is rarely done to check the extent to which their implementation accords with good governance p...
Data
Historically, tree planting schemes were primarily implemented to achieve economic functions; however, environmental and social goals have recently started to be targeted. This is due to the realisation that schemes operate in a socio-ecological system; hence, understanding and fulfilling local social (community) interests is imperative. However, t...
Article
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Many species have been intentionally introduced to new regions for their benefits. Some of these alien species cause damage, others do not (or at least have not yet). There are several approaches to address this problem: prohibit taxa that will cause damage, try to limit damages while preserving benefits, or promote taxa that are safe. In the prese...
Article
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The Kunming-Montreal Global Biodiversity Framework (GBF) calls for a 50% reduction in rates of invasive alien species establishment by 2030. However, estimating changes in rates of introduction and establishment is far from straightforward, particularly on a national scale. Variation in survey effort over time, the absence of data on survey effort,...
Article
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Understanding how and why plants are driven to extinction is important if future extinctions are to be prevented. Here we examined reasons for extinctions of plants using data from the South African Red List, which includes 33 Extinct taxa from 15 families and 24 genera including seven infraspecific taxa. We also compared Extinct taxa with those th...
Article
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Effective biodiversity management and policy decisions require timely access to accurate and reliable information on biodiversity status, trends, and threats. However, the process of data cleaning, aggregation, and analysis is often time-consuming, convoluted, laborious, and irreproducible. Biodiversity monitoring across large areas faces challenge...
Article
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Species can be both native and alien to a given administrative region. Here we present the first consolidated inventory of these ‘native-alien populations’ for South Africa, and provide an overview of the data it contains. To gather data, literature searches were performed and experts were consulted both directly and via an on-line survey. Putative...
Technical Report
Full-text available
Biological invasions are a major threat to South Africa’s biodiversity, economy, and sustainable development. This report is part of South Africa’s commitment to alleviating these impacts. It is a comprehensive national-scale assessment with contributions from 28 experts from 16 institutions. Drafts of the report were available for comment in two s...
Article
Acari, as with other small arthropods, are most commonly introduced to new areas as contaminants of agricultural trade. The biosecurity risk of such trade is managed by national and regional biosecurity systems, a chief aim of which is to prevent the introduction of agricultural and environmental pests. However, agricultural contaminants are introd...
Article
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Psidium cattleyanum (Myrtaceae) is a widespread invasive species in several countries, particularly on oceanic islands. The species was first recorded in South Africa in 1948 and has since established self-sustaining populations. We present the first comprehensive evaluation of the invasiveness of P. cattleyanum in South Africa by: 1) mapping the c...
Article
Cultivated plants provide food, fiber, and energy but they can escape, de-domesticate, colonize agroecosystems as weeds, and disrupt natural ecosystems as invasive species. Escape and invasion depend on traits of the species, type and rate of domestication, and cultivation context. Understanding this “de-domestication invasion process” is critical...
Article
Large sums of money are spent globally on invasive alien plant control projects, but their effectiveness in the medium to long term is seldom reported. Here we review the cost, extent and effectiveness of the management of plant invasions by South Africa's “Working for Water” program between 1998 and 2020. We use a broad framework of indicators for...
Article
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Knowledge of the introduction history and spread dynamics of invasive species can provide important insights for management (Ens et al. in Environ Rev (in press), 2022), however such information is often unavailable for accidental introductions. Here we infer how the European shore crab, Carcinus maenas , and its congener, the Mediterranean shore c...
Article
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Species introduced through human-related activities beyond their native range, termed alien species, have various impacts worldwide. The IUCN Environmental Impact Classification for Alien Taxa (EICAT) is a global standard to assess negative impacts of alien species on native biodiversity. Alien species can also positively affect biodiversity (for i...
Article
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Regulations provide the legal basis for managing biological invasions, but assessments of their effectiveness are rare. To assess the influence of national and local regulations on alien plant species richness and composition in a large protected area (Kruger National Park [KNP], South Africa) we surveyed tourist camps and staff villages for alien...
Article
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The total impact of an alien species was conceptualised as the product of its range size, local abundance and per-unit effect in a seminal paper by Parker et al. (Biol Invasions 1:3–19, 1999). However, a practical approach for estimating the three components has been lacking. Here, we generalise the impact formula and, through use of regression mod...
Article
Full-text available
Many countries define nativity at a country-level—taxa are categorised as either alien species or native species. However, there are often substantial within-country biogeographical barriers and so a taxon can be native and alien to different parts of the same country. Here, we use the term ‘native-alien populations’ as a short-hand for populations...
Article
Full-text available
Perspectives in conservation are based on a variety of value systems. Such differences in how people value nature and its components lead to different evaluations of the morality of conservation goals and approaches, and often underlie disagreements in the formulation and implementation of environmental management policies. Specifically, whether a...
Article
Full-text available
Agricultural biosecurity interventions are aimed at minimizing introductions of harmful non‐native organisms to new areas via agricultural trade. To prioritize such interventions, historical data on interceptions have been used to elucidate which factors determine the likelihood that a particular import is carrying a harmful organism. Here we use a...
Article
Full-text available
Purpose of Review Within the discipline of invasion science, researchers studying different taxonomic groups have developed distinct ways of investigating the phenomenon of biological invasions. While there have been efforts to reconcile these differences, a lack of knowledge of diversity, biogeography and ecology hampers researchers seeking to und...
Preprint
Full-text available
The total impact of an alien species was conceptualised as the product of its range size, local abundance and per-unit effect in a seminal paper by Parker and colleagues in 1999, but a practical approach for estimating the three components has been lacking. Here, we generalise the impact formula and, through use of regression models, estimate the r...
Article
Recent studies on patterns of biological invasions in several plant families have confirmed general findings (e.g., taxa with larger native range sizes are more likely to become invasive; and taxa with longer residence time in new regions are more likely to naturalise) and highlighted some context-specific findings relevant for management (e.g., re...
Article
Full-text available
Context dependence is widely invoked to explain disparate results in ecology. It arises when the magnitude or sign of a relationship varies due to the conditions under which it is observed. Such variation, especially when unexplained, can lead to spurious or seemingly contradictory conclusions, which can limit understanding and our ability to trans...
Preprint
Full-text available
Invasive alien species are repeatedly shown to be amongst the top threats to biodiversity globally. Robust indicators for measuring the status and trends of biological invasions are lacking, but essential for monitoring biological invasions and the effectiveness of interventions. Here, we formulate and demonstrate three such indicators that capture...
Article
Full-text available
Biodiversity and economic losses resulting from invasive plant pests and pathogens are increasing globally. For these impacts and threats to be managed effectively, appropriate methods of surveillance, detection and identification are required. Botanical gardens provide a unique opportunity for biosecurity as they accommodate diverse collections of...
Technical Report
Full-text available
Biological invasions are a major threat to South Africa’s biodiversity, economy, and sustainable development. This report is a part of South Africa’s commitment to alleviating these impacts. It is a comprehensive national-scale assessment with contributions from 36 experts from 16 institutions. Drafts of the report were available for comment in two...
Data
Supplementary material to Zengeya, T.A. & Wilson, J.R. (eds.) 2020. The status of biological invasions and their management in South Africa in 2019. Provides additional information chapter by chapter on the methods used, discussion points, and tables and figures
Article
Background and aims: Invasive species may undergo rapid evolution despite very limited standing genetic diversity. This so-called genetic paradox of biological invasions assumes that an invasive species has experienced (and survived) a genetic bottleneck and then underwent local adaptation in the new range. In this study, we test how often Austral...
Article
Full-text available
Biosecurity interception records are crucial data underlying efforts to predict and manage pest and pathogen introductions. Here we present a dataset containing information on imported plant products inspected by the South African Department of Agriculture's laboratories between 1994 and 2019 and the contaminant organisms found on them. Samples wer...
Article
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The establishment success of a population is a function of abiotic and biotic factors and introduction dynamics. Understanding how these factors interact has direct consequences for understanding and managing biological invasions and for applied ecology more generally. Here we use a mesocosm approach to explore how the size of founding populations...
Article
Full-text available
The growing interest in commercial cultivation of bamboos (Poaceae subfamily Bambusoideae) has led to the introduction of new alien species into South Africa. The rate at which bamboos are being planted in South Africa is a cause for concern because of the impacts of bamboo invasions in other parts of the world. To understand the risks associated w...
Article
Full-text available
The regulation of biological invasions is often focussed at the species level. However, the risks posed by infra-and inter-specific entities can be significantly different from the risks posed by the corresponding species, to the extent that they should be regulated and managed differently. In particular, many ornamental plants have been the subjec...
Article
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The IUCN recommends the use of two distinct schemes to assess the impacts of biological invasions on biodiversity at the species level. The IUCN Red List of Threatened Species (Red List) categorises native species based on their risk of extinction. Such assessments evaluate the extent to which different pressures, including alien species, threaten...
Article
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Macroecology is the study of patterns, and the processes that determine those patterns, in the distribution and abundance of organisms at large scales, whether they be spatial (from hundreds of kilometres to global), temporal (from decades to centuries), and organismal (numbers of species or higher taxa). In the context of invasion ecology, macroec...
Article
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Our understanding and management of biological invasions relies on our ability to classify and conceptualise the phenomenon. This need has stimulated the development of a plethora of frameworks, ranging in nature from conceptual to applied. However, most of these frameworks have not been widely tested and their general applicability is unknown. In...
Article
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The need to understand and manage biological invasions has driven the development of frameworks to circumscribe, classify, and elucidate aspects of the phenomenon. But how influential have these frameworks really been? To test this, we evaluated the impact of a pathway classification framework, a framework focussing on the introduction-naturalisati...
Article
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Alien species are introduced to new regions in many different ways and for different purposes. A number of frameworks have been developed to group such pathways of introduction into discrete categories in order to improve our understanding of biological invasions, provide information for interventions that aim to prevent introductions, enable repor...
Article
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Human livelihoods and well-being in almost all regions of the world depend on taxa which are alien. Such taxa also, however, threaten human health, sustainable development, and biodiversity. Since it is not feasible or desirable to control all alien taxa, decision-makers increasingly rely on risk analyses to formalise the best available evidence of...
Article
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The year 2020 and the next few years are critical for the development of the global biodiversity policy agenda until the mid-21 st century, with countries agreeing to a Post-2020 Global Biodiversity Framework under the Convention on Biological Diversity (CBD). Reducing the substantial and still rising impacts of invasive alien species (IAS) on biod...
Article
Full-text available
Sustainably managed non-native trees deliver economic and societal benefits with limited risk of spread to adjoining areas. However, some plantations have launched invasions that cause substantial damage to biodiversity and ecosystem services, while others pose substantial threats of causing such impacts. The challenge is to maximise the benefits o...
Article
Full-text available
Sustainably managed non-native trees deliver economic and societal benefits with limited risk of spread to adjoining areas. However, some plantations have launched invasions that cause substantial damage to biodiversity and ecosystem services, while others pose substantial threats of causing such impacts. The challenge is to maximise the benefits o...
Article
Full-text available
UNESCO World Heritage Sites (WHS) are areas of outstanding universal value and conservation importance. They are, however, threatened by a variety of global change drivers, including biological invasions. We assessed the current status of biological invasions and their management in 241 natural and mixed WHS globally by reviewing documents collated...
Preprint
Full-text available
Perspectives in conservation can be based on a variety of value systems and normative postulates. Perspectives also vary between cultures. Such differences in what and how people value nature, underlie many disagreements and conflicts during the formulation and implementation of environmental management policies. Specifically, whether an action int...
Article
Full-text available
Background: The effectiveness of invasive alien species management in South Africa, and elsewhere, can be improved by ensuring there are strong links and feedbacks between science and management. The CAPE Invasive Alien Animals Working Group (CAPE IAAWG) was established in 2008 to enhance cooperation among stakeholders such as implementing agencies...
Article
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Biodiversity data are being collected at unprecedented rates. Such data often have significant value for purposes beyond the initial reason for which they were collected, particularly when they are combined and collated with other data sources. In the field of invasion ecology, however, integrating data represents a major challenge due to the notor...
Article
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Our ability to predict invasions has been hindered by the seemingly idiosyncratic context-dependency of individual invasions. However, we argue that robust and useful generalisations in invasion science can be made by considering “invasion syndromes” which we define as “a combination of pathways, alien species traits, and characteristics of the rec...
Article
Biological invasions severely impact on marine ecosystems around the world, but to date management is rare and has not previously been attempted in Africa. This study documents a trial management programme aimed at informing a national management strategy for the invasive European shore crab, Carcinus maenas, in South Africa. The approach involved...
Article
The pet trade has been a major pathway for the introduction of vertebrate invaders, but little is known about its role in invertebrate invasions. Here we assess the trade in terrestrial invertebrates (excluding spiders) in South Africa and the potential of this trade to result in biological invasions and impacts. Pet stores, websites, and expositio...
Chapter
Full-text available
Since 1995, the South African government has spent at least ZAR 15 billion (unadjusted for inflation; approximately USD1 billion) on alien plant control operations across South Africa. The amount spent per year has risen exponentially since 2010, and in 2019 annual spending is around ZAR 2 billion per year. Based on a small (but growing) number of...
Chapter
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Risk analysis is an important decision-support tool for the management of biological invasions. South Africa, as a signatory to international agreements, has enacted legislation requiring risk analyses to be conducted if trade is to be restricted or regulated and if alien species are to be introduced. In this chapter, we outline the various needs f...
Chapter
Full-text available
This chapter provides the first assessment of South African native vascular plants as naturalised and invasive species in other parts of the world. For naturalised species, Global Naturalized Alien Flora (GloNAF) data were used, while for invasive species an assessment was made using the peer-reviewed literature, experience of the authors, and corr...