Browsing by Author "Bacher, S."
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- ItemAddressing a critique of the TEASI framework for invasive species risk assessment(John Wiley & Sons Ltd/CNRS, 2013) Leung, B.; Roura-Pascual, N.; Bacher, S.; Heikkila, J.; Brotons, L.; Burgman, M.A.; Dehnen-Schmutz, K.; Essl, F.; Hulme, P.E.; Richardson, D.M.; Sol, D.; Vila, M.We address criticism that the Transport, Establishment, Abundance, Spread, Impact (TEASI) framework does not facilitate objective mapping of risk assessment methods nor defines best practice. We explain why TEASI is appropriate for mapping, despite inherent challenges, and how TEASI offers considerations for best practices, rather than suggesting one best practice.
- ItemAppropriate uses of EICAT protocol, data and classifications(2020) Kumschick, S.; Bacher, S.; Bertolino, S.; Blackburn, T.M.; Evans, T.; Roy, H.E.; Smith, K.The Environmental Impact Classification for Alien Taxa (EICAT) can be used to classify alien taxa according to the magnitude and type of their environmental impacts. The EICAT protocol, classifications of alien taxa using the protocol (EICAT classification) and the data underpinning classifications (EICAT data) are increasingly used by scientists and practitioners such as governments, NGOs and civil society for a variety of purposes. However, the properties of the EICAT protocol and the data it generates are not suitable for certain uses. Therefore, we present guidelines designed to clarify and facilitate the appropriate use of EICAT to tackle a broad range of conservation issues related to biological invasions, as well as to guide research and communication more generally. Here we address common misconceptions and give a brief overview of some key issues that all EICAT users need to be aware of to take maximal advantage of this resource. Furthermore, we give examples of the wide variety of ways in which the EICAT protocol, classifications and data can be and have been utilised and outline common errors and pitfalls to avoid.
- ItemA conceptual framework for prioritization of invasive alien species for management according to their impact(Pensoft, 2012-12-14) Kumschick, S.; Bacher, S.; Dawson, W.; Heikkila, J.; Sendek, A.; Pluess, T.; Robinson, T. B.; Kuhn, I.The number of invasive alien species is increasing and so are the impacts these species cause to the environment and economies. Nevertheless, resources for management are limited, which makes prioritization unavoidable. We present a prioritization framework which can be useful for decision makers as it includes both a scientific impact assessment and the evaluation of impact importance by affected stakeholders. The framework is divided into five steps, namely 1) stakeholder selection and weighting of stakeholder importance by the decision maker, 2) factual description and scoring of changes by scientists, 3) evaluation of the importance of impact categories by stakeholders, 4) calculation of weighted impact categories and 5) calculation of final impact score and decision making. The framework could be used at different scales and by different authorities. Furthermore, it would make the decision making process transparent and retraceable for all stakeholders and the general public.
- ItemA conceptual framework for range-expanding species that track human-induced environmental change(2019) Essl, F.; Dullinger, S.; Genovesi, P.; Hulme, P.E.; Jeschke, J.M.; Katsanevakis, S.; Kühn, I.; Lenzner, B.; Pauchard, A.; Pyšek, P.; Rabitsch, W.; Richardson, D.M.; Seebens, H.; van Kleunen, M.; van der Putten, W.H.; Vilà, M.; Bacher, S.For many species, human-induced environmental changes are important indirect drivers of range expansion into new regions. We argue that it is important to distinguish the range dynamics of such species from those that occur without, or with less clear, involvement of human-induced environmental changes. We elucidate the salient features of the rapid increase in the number of species whose range dynamics are human induced, and review the relationships and differences to both natural range expansion and biological invasions. We discuss the consequences for science, policy and management in an era of rapid global change and highlight four key challenges relating to basic gaps in knowledge, and the transfer of scientific understanding to biodiversity management and policy. We conclude that range-expanding species responding to human-induced environmental change will become an essential feature for biodiversity management and science in the Anthropocene. Finally, we propose the term neonative for these taxa.
- ItemCrossing frontiers in tackling pathways of biological invasions(Oxford University Press, 2015) Essl, F.; Bacher, S.; Blackburn, T.M.; Booy, O.; Brundu, G.; Brunel, S.; Cardoso, A.C.; Eschen, R.; Gallardo, B.; Galil, B.; Garcia-Berthou, E.; Genovesi, P.; Groom, Q.; Harrower, C.; Hulme, P.E.; Katsanevakis, S.; Kenis, M.; Kuhn, I.; Kumschick, S.; Martinou, A.F.; Nentwig, W.; O'Flynn, C.; Pagad, S.; Pergl, J.; Pysek, P.; Rabitsch, W.; Richardson, D.M.; Roques, A.; Roy, H.E.; Scalera, R.; Schindler, S.; Seebens, H.; Vanderhoeven, S.; Vila, M.; Wilson, J.R.U.; Zenetos, A.; Jeschke, J.M.Substantial progress has been made in understanding how pathways underlie and mediate biological invasions. However, key features of their role in invasions remain poorly understood, available knowledge is widely scattered, and major frontiers in research and management are insufficiently characterized. We review the state of the art, highlight recent advances, identify pitfalls and constraints, and discuss major challenges in four broad fields of pathway research and management: pathway classification, application of pathway information, management response, and management impact. We present approaches to describe and quantify pathway attributes (e.g., spatiotemporal changes, proxies of introduction effort, environmental and socioeconomic contexts) and how they interact with species traits and regional characteristics. We also provide recommendations for a research agenda with particular focus on emerging (or neglected) research questions and present new analytical tools in the context of pathway research and management.
- ItemDefining the impact of non-native species(Wiley Periodicals, Inc. on behalf of the Society for Conservation Biology, 2014) Jeschke, J.M.; Bacher, S.; Blackburn, T.M.; Dick, J.T.A.; Essl, F.; Evans, T.; Gaertner, M.; Hulme, P.E.; Kühn, I.; Mrugala, A.; Pergl, J.; Pyšek, P.; Rabitsch, W.; Ricciardi, A.; Richardson, D.M.; Sendek, A.; Vilá, M.; Winter, M.; Kumschick, S.Non-native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non-native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non-native species will promote progress toward a better understanding of the implications of changes to biodiversity and ecosystems caused by non-native species; help disentangle which aspects of scientific debates about non-native species are due to disparate definitions and which represent true scientific discord; and improve communication between scientists from different research disciplines and between scientists, managers, and policy makers. For these reasons and based on examples from the literature, we devised seven key questions that fall into 4 categories: directionality, classification and measurement, ecological or socio-economic changes, and scale. These questions should help in formulating clear and practical definitions of impact to suit specific scientific, stakeholder, or legislative contexts.
- ItemDrivers of future alien species impacts: an expert-based assessment(2020) Essl, F.; Lenzner, B.; Bacher, S.; Bailey, S.; Capinha, C.; Daehler, C.; Dullinger, S.; Genovesi, P.; Hui, C.; Hulme, P.E.; Jeschke, J.M.; Katsanevakis, S.; Kühn, I.; Leung, B.; Liebhold, A.; Liu, C.; MacIsaac, H.J.; Meyerson, L.A.; Nuñez, M.A.; Pauchard, A.; Pyšek, P.; Rabitsch, W.; Richardson, D.M.; Roy, H.E.; Ruiz, G.M.; Russell, J.C.; Sanders, N.J.; Sax, D.F.; Scalera, R.; Seebens, H.; Springborn, M.; Turbelin, A.; van Kleunen, M.; von Holle, B.; Winter, M.; Zenni, R.D.; Mattsson, B.J.; Roura-Pascual, N.Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio-economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid-21st century. Based on responses from 36 experts in biological invasions, moderate (20%–30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions—transport, climate change and socio-economic change—were predicted to significantly affect future impacts of alien species on biodiversity even under a best-case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best-case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post-2020 Framework of the Convention on Biological Diversity.
- ItemEcological impacts of alien species: Quantification, scope, caveats, and recommendations(Oxford University Press, 2015) Kumschick, S.; Gaertner, M.; Vila, M.; Essl, F.; Jeschke, J.M.; Pysek, P.; Ricciardi, A.; Bacher, S.; Blackburn, T.M.; Dick, J.T.A.; Evans, T.; Hulme, P.E.; Kuhn, I.; Mrugala, A.; Pergl, J.; Rabitsch, W.; Richardson, D.M.; Sendek, A.; Winter, M.Despite intensive research during the past decade on the effects of alien species, invasion science still lacks the capacity to accurately predict the impacts of those species and, therefore, to provide timely advice to managers on where limited resources should be allocated. This capacity has been limited partly by the context-dependent nature of ecological impacts, research highly skewed toward certain taxa and habitat types, and the lack of standardized methods for detecting and quantifying impacts. We review different strategies, including specific experimental and observational approaches, for detecting and quantifying the ecological impacts of alien species. These include a four-way experimental plot design for comparing impact studies of different organisms. Furthermore, we identify hypothesis-driven parameters that should be measured at invaded sites to maximize insights into the nature of the impact. We also present strategies for recognizing high-impact species. Our recommendations provide a foundation for developing systematic quantitative measurements to allow comparisons of impacts across alien species, sites, and time.
- ItemEcological impacts of alien species: Quantification, scope, caveats, and recommendations(Oxford University Press, 2015) Kumschick, S.; Gaertner, M.; Vila, M.; Essl, F.; Jeschke, J.M.; Pysek, P.; Ricciardi, A.; Bacher, S.; Blackburn, T.M.; Dick, J.T.A.; Evans, T.; Hulme, P.E.; Kuhn, I.; Mrugala, A.; Pergl, J.; Rabitsch, W.; Richardson, D.M.; Sendek, A.; Winter, M.Despite intensive research during the past decade on the effects of alien species, invasion science still lacks the capacity to accurately predict the impacts of those species and, therefore, to provide timely advice to managers on where limited resources should be allocated. This capacity has been limited partly by the context-dependent nature of ecological impacts, research highly skewed toward certain taxa and habitat types, and the lack of standardized methods for detecting and quantifying impacts. We review different strategies, including specific experimental and observational approaches, for detecting and quantifying the ecological impacts of alien species. These include a four-way experimental plot design for comparing impact studies of different organisms. Furthermore, we identify hypothesis-driven parameters that should be measured at invaded sites to maximize insights into the nature of the impact. We also present strategies for recognizing high-impact species. Our recommendations provide a foundation for developing systematic quantitative measurements to allow comparisons of impacts across alien species, sites, and time.
- ItemFramework and guidelines for implementing the proposed IUCN Environmental Impact Classification for Alien Taxa (EICAT)(John Wiley & Sons Ltd, 2015) Hawkins, C.L.; Bacher, S.; Essl, F.; Hulme, P.E.; Jeschke, J.M.; Kuhn, I.; Kumschick, S.; Nentwig, W.; Pergl, J.; Pysek, P.; Rabitsch, W.; Richardson, D.M.; Vila, M.; Wilson, J.R.U.; Genovesi, P.; Blackburn, T.M.Recently, Blackburn et al. (2014) developed a simple, objective and transparent method for classifying alien taxa in terms of the magnitude of their detrimental environmental impacts in recipient areas. Here, we present a comprehensive framework and guidelines for implementing this method, which we term the Environmental Impact Classification for Alien Taxa, or EICAT. We detail criteria for applying the EICAT scheme in a consistent and comparable fashion, prescribe the supporting information that should be supplied along with classifications, and describe the process for implementing the method. This comment aims to draw the attention of interested parties to the framework and guidelines, and to present them in their entirety in a location where they are freely accessible to any potential users.
- ItemFrameworks used in invasion science: progress and prospects(2020) Wilson, J.R.U.; Bacher, S.; Daehler, C.C.; Groom, Q.J.; Kumschick, S.; Lockwood, J.L.; Robinson, T.B.; Zengeya, T.A.; Richardson, D.M.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 order to critically evaluate frameworks in invasion science, we held a workshop on ‘Frameworks used in Invasion Science’ hosted by the DSI-NRF Centre of Excellence for Invasion Biology in Stellenbosch, South Africa, in November 2019, which led to this special issue. For the purpose of the workshop we defined a framework as “a way of organising things that can be easily communicated to allow for shared understanding or that can be implemented to allow for generalisations useful for research, policy or management”. Further, we developed the Stellenbosch Challenge for Invasion Science: “Can invasion science develop and improve frameworks that are useful for research, policy or management, and that are clear as to the contexts in which the frameworks do and do not apply?”. Particular considerations identified among meeting participants included the need to identify the limitations of a framework, specify how frameworks link to each other and broader issues, and to improve how frameworks can facilitate communication. We believe that the 24 papers in this special issue do much to meet this challenge. The papers apply existing frameworks to new data and contexts, review how the frameworks have been adopted and used, develop useable protocols and guidelines for applying frameworks to different contexts, refine the frameworks in light of experience, integrate frameworks for new purposes, identify gaps, and develop new frameworks to address issues that are currently not adequately dealt with. Frameworks in invasion science must continue to be developed, tested as broadly as possible, revised, and retired as contexts and needs change. However, frameworks dealing with pathways of introduction, progress along the introduction-naturalisation-invasion continuum, and the assessment of impacts are being increasingly formalised and set as standards. This, we argue, is an important step as invasion science starts to mature as a discipline.
- ItemThe importance of assessing positive and beneficial impacts of alien species(2020) Vimercati, G.; Kumschick, S.; Probert, A.F.; Volery, L.; Bacher, S.Extensive literature is available on the diversity and magnitude of impacts that alien species cause on recipient systems. Alien species may decrease or increase attributes of ecosystems (e.g. total biomass or species diversity), thus causing negative and positive environmental impacts. Alien species may also negatively or positively impact attributes linked to local human communities (e.g. the number of people involved in a given activity). Ethical and societal values contribute to define these environmental and socio-economic impacts as deleterious or beneficial. Whilst most of the literature focuses on the deleterious effects of alien taxa, some recognise their beneficial impacts on ecosystems and human activities. Impact assessment frameworks show a similar tendency to evaluate mainly deleterious impacts: only relatively few, and not widely applied, frameworks incorporate the beneficial impacts of alien species. Here, we provide a summary of the frameworks assessing beneficial impacts and briefly discuss why they might have been less frequently cited and applied than frameworks assessing exclusively deleterious impacts. Then, we review arguments that invoke a greater consideration of positive and beneficial impacts caused by alien species across the invasion science literature. We collate and describe arguments from a set of 47 papers, grouping them in two categories (value-free and value-laden), which span from a theoretical, basic science perspective to an applied science perspective. We also provide example cases associated with each argument. We advocate that the development of transparent and evidence-based frameworks assessing positive and beneficial impacts might advance our scientific understanding of impact dynamics and better inform management and prioritisation decisions. We also advise that this development should be achieved by recognising the underlying ethical and societal values of the frameworks and their intrinsic limitations. The evaluation of positive and beneficial impacts through impact assessment frameworks should not be seen as an attempt to outweigh or to discount deleterious impacts of alien taxa but rather as an opportunity to provide additional information for scientists, managers and policymakers.
- ItemImproving the Environmental Impact Classification for Alien Taxa (EICAT): a summary of revisions to the framework and guidelines(2020) Volery, L.; Blackburn, T.M.; Bertolino, S.; Evans, T.; Genovesi, P.; Kumschick, S.; Roy, H.E.; Smith, K.G.; Bacher, S.The Environmental Impact Classification for Alien Taxa (EICAT) classifies the impacts caused by alien species in their introduced range in standardised terms across taxa and recipient environments. Impacts are classified into one of five levels of severity, from Minimal Concern to Massive, via one of 12 impact mechanisms. Here, we explain revisions based on an IUCN-wide consultation process to the previously-published EICAT framework and guidelines, to clarify why these changes were necessary. These changes mainly concern: the distinction between the two highest levels of impact severity (Major and Massive impacts), the scenarios of the five levels of severity for the hybridisation and disease transmission mechanisms, the broadening of existing impact mechanisms to capture overlooked mechanisms, the Current (Maximum) Impact, and the way uncertainty of individual impact assessments is evaluated. Our aim in explaining this revision process is to ensure consistency of EICAT assessments, by improving the understanding of the framework.
- ItemInvasion costs, impacts, and human agency: response to Sagoff 2020(2020) Cuthbert, R.N.; Bacher, S.; Blackburn, T.M.; Briski, E.; Diagne, C.; Dick, J.T.A.; Essl, F.; Genovesi, P.; Haubrock, P.J.; Latombe, G.; Lenzner, B.; Meinard, Y.; Pauchard, A.; Pyšek, P.; Ricciardi, A.; Richardson, D.M.; Russell, J.C.; Simberloff, D.; Courchamp, F.Article impact statement: In an era of profound biodiversity crisis, invasion costs, invader impacts, and human agency should not be dismissed.
- ItemInvasion syndromes: a systematic approach for predicting biological invasions and facilitating effective management(2020) Novoa, A.; Richardson, D.M.; Pyšek, P.; Meyerson, L.A.; Bacher, S.; Canavan, S.; Catford, J.A.; Čuda, J.; Essl, F.; Foxcroft, L.C.; Genovesi, P.; Hirsch, H.; Hui, C.; Jackson, M.C.; Kueffer, C.; Le Roux, J.J.; Measey, J.; Mohanty, N.P.; Moodley, D.; Müller-Schärer, H.; Packer, J.G.; Pergl, J.; Robinson, T.B.; Saul, W.C.; Shackleton, R.T.; Visser, V.; Weyl, O.L.F.; Yannelli, F.A.; Wilson, J.R.U.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 recipient ecosystem which collectively result in predictable dynamics and impacts, and that can be managed effectively using specific policy and management actions”. We describe this approach and outline examples that highlight its utility, including: cacti with clonal fragmentation in arid ecosystems; small aquatic organisms introduced through ballast water in harbours; large ranid frogs with frequent secondary transfers; piscivorous freshwater fishes in connected aquatic ecosystems; plant invasions in high-elevation areas; tall-statured grasses; and tree-feeding insects in forests with suitable hosts. We propose a systematic method for identifying and delimiting invasion syndromes. We argue that invasion syndromes can account for the context-dependency of biological invasions while incorporating insights from comparative studies. Adopting this approach will help to structure thinking, identify transferrable risk assessment and management lessons, and highlight similarities among events that were previously considered disparate invasion phenomena.
- ItemMAcroecological Framework for Invasive Aliens (MAFIA): disentangling large-scale context dependence in biological invasions(2020) Pyšek, P.; Bacher, S.; Kühn, I.; Novoa, A.; Catford, J.A.; Hulme, P.E.; Pergl, J.; Richardson, D.M.; Wilson, J.R.U.; Blackburn, T.M.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, macroecological studies include, for example, analyses of the richness, diversity, distribution, and abundance of alien species in regional floras and faunas, spatio-temporal dynamics of alien species across regions, and cross-taxonomic analyses of species traits among comparable native and alien species pools. However, macroecological studies aiming to explain and predict plant and animal naturalisations and invasions, and the resulting impacts, have, to date, rarely considered the joint effects of species traits, environment, and socioeconomic characteristics. To address this, we present the MAcroecological Framework for Invasive Aliens (MAFIA). The MAFIA explains the invasion phenomenon using three interacting classes of factors – alien species traits, location characteristics, and factors related to introduction events – and explicitly maps these interactions onto the invasion sequence from transport to naturalisation to invasion. The framework therefore helps both to identify how anthropogenic effects interact with species traits and environmental characteristics to determine observed patterns in alien distribution, abundance, and richness; and to clarify why neglecting anthropogenic effects can generate spurious conclusions. Event-related factors include propagule pressure, colonisation pressure, and residence time that are important for mediating the outcome of invasion processes. However, because of context dependence, they can bias analyses, for example those that seek to elucidate the role of alien species traits. In the same vein, failure to recognise and explicitly incorporate interactions among the main factors impedes our understanding of which macroecological invasion patterns are shaped by the environment, and of the importance of interactions between the species and their environment. The MAFIA is based largely on insights from studies of plants and birds, but we believe it can be applied to all taxa, and hope that it will stimulate comparative research on other groups and environments. By making the biases in macroecological analyses of biological invasions explicit, the MAFIA offers an opportunity to guide assessments of the context dependence of invasions at broad geographical scales.
- ItemNo saturation in the accumulation of alien species worldwide(Nature Research (part of Springer Nature), 2017) Seebens, Hanno; Blackburn, T. M.; Dyer, E. E.; Genovesi, P.; Hulme, P. E.; Jeschke, J. M.; Pagad, S.; Pysek, P.; Winter, M.; Arianoutsou, M.; Bacher, S.; Blasius, B.; Brundu, G.; Capinha, G.; Celesti-Grapow, L.; Dawson, W.; Dullinger, S.; Fuentes, N.; Jager, H.; Kartesz, J.; Kenis, M.; Kreft, H.; Kuhn, I; Lenzner, B.; Liebhold, A.; Mosena, A.; Moser, D.; Nishino, M.; Pearman, D.; Pergl, J.; Rabitsch, W.; Rojas-Sandoval, J.; Roques, A.; Rorke, S.; Rossinelli, S.; Roy, H. E.; Scalera, R.; Schindler, S.; Stajerova, K.; Tokarska-Guzik, B.; Van Kleunen, M.; Walker, K.; Weigelt, P.; Yamanaka, T.; Essl, F.Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970–2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization.
- ItemScientific and normative foundations for the valuation of alien-species impacts: Thirteen core principles(Oxford University Press, 2017) Essl, F.; Hulme, P.E.; Jeschke, J.M.; Keller, R.; Pysek, P.; Richardson, D.M.; Saul, W.C.; Bacher, S.; Dullinger, S.; Estevez, R.A.; Kueffer, C.; Roy, H.E.; Seebens, H.; Rabitsch, W.Biological invasions cause many impacts that differ widely in how they are perceived. We argue that many conflicts in the valuation of the impacts of alien species are attributable to differences in the framing of the issue and implicit assumptions—such conflicts are often not acknowledged. We present 13 principles that can help guide valuation and therefore inform the management of alien species. Seven of these relate to the science domain, representing aspects of change caused by alien species that can be measured or otherwise assessed using scientific methods. The remaining six principles invoke values, risk perception, and environmental ethics, but also cognitive and motivational decision biases. We illustrate the consequences of insufficient appreciation of these principles. Finally, we provide guidance rooted in political agreements and environmental ethics for improving the consideration of the consequences of these principles and present appropriate tools for management decisions relating to alien species.
- ItemSocio-economic impact classification of alien taxa (SEICAT)(British Ecological Society, 2018) Bacher, S.; Blackburn, T.M.; Essl, F.; Genovesi, P.; Heikkilä, J.; Jeschke, J.M.; Jones, G.; Keller, R.; Kenis, M.; Kueffer, C.; Martinou, A.F.; Nentwig, W.; Pergl, J.; Pyšek, P.; Rabitsch, W.; Richardson, D.M.; Roy, H.E.; Saul, W.-C.; Scalera, R.; Vilà, M.; Wilson, J.R.U.; Kumschick, S.1. Many alien taxa are known to cause socio-economic impacts by affecting the different constituents of human well-being (security; material and non-material assets; health; social, spiritual and cultural relations; freedom of choice and action). Attempts to quantify socio-economic impacts in monetary terms are unlikely to provide a useful basis for evaluating and comparing impacts of alien taxa because they are notoriously difficult to measure and important aspects of human well-being are ignored. 2. Here, we propose a novel standardised method for classifying alien taxa in terms of the magnitude of their impacts on human well-being, based on the capability approach from welfare economics. The core characteristic of this approach is that it uses changes in peoples’ activities as a common metric for evaluating impacts on well-being. 3. Impacts are assigned to one of five levels, from Minimal Concern to Massive, according to semi-quantitative scenarios that describe the severity of the impacts. Taxa are then classified according to the highest level of deleterious impact that they have been recorded to cause on any constituent of human well-being. The scheme also includes categories for taxa that are not evaluated, have no alien population, or are data deficient, and a method for assigning uncertainty to all the classifications. To demonstrate the utility of the system, we classified impacts of amphibians globally. These showed a variety of impacts on human well-being, with the cane toad (Rhinella marina) scoring Major impacts. For most species, however, no studies reporting impacts on human well-being were found, i.e. these species were data deficient. 4. The classification provides a consistent procedure for translating the broad range of measures and types of impact into ranked levels of socio-economic impact, assigns alien taxa on the basis of the best available evidence of their documented deleterious impacts, and is applicable across taxa and at a range of spatial scales. The system was designed to align closely with the Environmental Impact Classification for Alien Taxa (EICAT) and the Red List, both of which have been adopted by the International Union of Nature Conservation (IUCN), and could therefore be readily integrated into international practices and policies.
- ItemUnderstanding uncertainty in the Impact Classification for Alien Taxa (ICAT) assessments(2020) Probert, A.F.; Volery, L.; Kumschick, S.; Vimercati, G.; Bacher, S.The Environmental Impact Classification for Alien Taxa (EICAT) and the Socio-Economic Impact Classification of Alien Taxa (SEICAT) have been proposed to provide unified methods for classifying alien species according to their magnitude of impacts. EICAT and SEICAT (herein “ICAT” when refered together) were designed to facilitate the comparison between taxa and invasion contexts by using a standardised, semi-quantitative scoring scheme. The ICAT scores are assigned after conducting a literature review to evaluate all impact observations against the protocols’ criteria. EICAT classifies impacts on the native biota of the recipient environments, whereas SEICAT classifies impacts on human activities. A key component of the process is to assign a level of confidence (high, medium or low) to account for uncertainty. Assessors assign confidence scores to each impact record depending on how confident they are that the assigned impact magnitude reflects the true situation. All possible sources of epistemic uncertainty are expected to be captured by one overall confidence score, neglecting linguistic uncertainties that assessors should be aware of. The current way of handling uncertainty is prone to subjectivity and therefore might lead to inconsistencies amongst assessors. This paper identifies the major sources of uncertainty for impacts classified under the ICAT frameworks, where they emerge in the assessment process and how they are likely to be contributing to biases and inconsistency in assessments. In addition, as the current procedures only capture uncertainty at the individual impact report, interspecific comparisons may be limited by various factors, including data availability. Therefore, ranking species, based on impact magnitude under the present systems, does not account for such uncertainty. We identify three types of biases occurring beyond the individual impact report level (and not captured by the confidence score): biases in the existing data, data collection and data assessment. These biases should be recognised when comparing alien species based on their impacts. Clarifying uncertainty concepts relevant to the ICAT frameworks will lead to more consistent impact assessments and more robust intra- and inter-specific comparisons of impact magnitudes.