SUNScholar - Browsing by Author "Roy, Helen E."

Browsing by Author "Roy, Helen E."

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Appropriate uses of EICAT protocol, data and classifications
(Pensoft, 2020-10-15) Kumschick, Sabrina; Bacher, Sven; Bertolino, Sandro; Blackburn, Tim M.; Evans, Thomas; Roy, Helen E.; Smith, Kevin
ENGLISH ABSTRACT: 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.
Horizon scanning for invasive alien species with the potential to threaten biodiversity in Great Britain
(John Wiley & Sons, 2014) Roy, Helen E.; Peyton, Jodey; Aldridge, David C.; Bantock, Tristan; Blackburn, Tim M.; Britton, Robert; Clark, Paul; Cook, Elizabeth; Dehnen-Schmutz, Katharina; Dines, Trevor; Dobson, Michael; Edwards, Francois; Harrower, Colin; Harvey, Martin C.; Minchin, Dan; Noble, David G.; Parrott, Dave; Pocock, Michael J. O.; Preston, Chris D.; Roy, Sugoto; Salisbury, Andrew; Schonrogge, Karsten; Sewell, Jack; Shaw, Richard H.; Stebbing, Paul; Stewart, Alan J. A.; Walker, Kevin J.
Invasive alien species (IAS) are considered one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change. Horizon scanning, the systematic examination of future potential threats and opportunities, leading to prioritization of IAS threats is seen as an essential component of IAS management. Our aim was to consider IAS that were likely to impact on native biodiversity but were not yet established in the wild in Great Britain. To achieve this, we developed an approach which coupled consensus methods (which have previously been used for collaboratively identifying priorities in other contexts) with rapid risk assessment. The process involved two distinct phases: 1. Preliminary consultation with experts within five groups (plants, terrestrial invertebrates, freshwater invertebrates, vertebrates and marine species) to derive ranked lists of potential IAS. 2. Consensus-building across expert groups to compile and rank the entire list of potential IAS. Five hundred and ninety-one species not native to Great Britain were considered. Ninety-three of these species were agreed to constitute at least a medium risk (based on score and consensus) with respect to them arriving, establishing and posing a threat to native biodiversity. The quagga mussel, Dreissena rostriformis bugensis, received maximum scores for risk of arrival, establishment and impact; following discussions the unanimous consensus was to rank it in the top position. A further 29 species were considered to constitute a high risk and were grouped according to their ranked risk. The remaining 63 species were considered as medium risk, and included in an unranked long list. The information collated through this novel extension of the consensus method for horizon scanning provides evidence for underpinning and prioritizing management both for the species and, perhaps more importantly, their pathways of arrival. Although our study focused on Great Britain, we suggest that the methods adopted are applicable globally.
Improving the Environmental Impact Classification for Alien Taxa (EICAT): a summary of revisions to the framework and guidelines
(Pensoft, 2020-10-15) Volery, Lara; Blackburn, Tim M.; Bertolino, Sandro; Evans, Thomas; Genovesi, Piero; Kumschick, Sabrina; Roy, Helen E.; Smith, Kevin G.; Bacher, Sven
ENGLISH ABSTRACT: 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.
Options for reducing uncertainty in impact classification for alien species
(2021) Clarke, David A.; Palmer, David J.; McGrannachan, Chris; Burgess, Treena I.; Chown, Steven L.; Clarke, Rohan H.; Kumschick, Sabrina; Lach, Lori; Liebhold, Andrew M.; Roy, Helen E.; Saunders, Manu E.; Yeates, David K.; Zalucki, Myron P.; McGeoch, Melodie A.
ENGLISH ABSTRACT: Impact assessment is an important and cost-effective tool for assisting in the identification and prioritization of invasive alien species. With the number of alien and invasive alien species expected to increase, reliance on impact assessment tools for the identification of species that pose the greatest threats will continue to grow. Given the importance of such assessments for management and resource allocation, it is critical to understand the uncertainty involved and what effect this may have on the outcome. Using an uncertainty typology and insects as a model taxon, we identified and classified the causes and types of uncertainty when performing impact assessments on alien species. We assessed 100 alien insect species across two rounds of assessments with each species independently assessed by two assessors. Agreement between assessors was relatively low for all three impact classification components (mechanism, severity, and confidence) after the first round of assessments. For the second round, we revised guidelines and gave assessors access to each other’s assessments which improved agreement by between 20% and 30% for impact mechanism, severity, and confidence. Of the 12 potential reasons for assessment discrepancies identified a priori, 11 were found to occur. The most frequent causes (and types) of uncertainty (i.e., differences between assessment outcomes for the same species) were as follows: incomplete information searches (systematic error), unclear mechanism and/or extent of impact (subjective judgment due to a lack of knowledge), and limitations of the assessment framework (context dependence). In response to these findings, we identify actions that may reduce uncertainty in the impact assessment process, particularly for assessing speciose taxa with diverse life histories such as Insects. Evidence of environmental impact was available for most insect species, and (of the non-random original subset of species assessed) 14 of those with evidence were identified as high impact species (with either major or massive impact). Although uncertainty in risk assessment, including impact assessments, can never be eliminated, identifying, and communicating its cause and variety is a first step toward its reduction and a more reliable assessment outcome, regardless of the taxa being assessed.
Scientists’ warning on invasive alien species
(Wiley, 2019) Pysek, Petr; Hulme, Philip E.; Simberloff, Dan; Bacher, Sven; Blackburn, Tim M.; Carlton, James T.; Dawson, Wayne; Essl, Franz; Foxcroft, Llewellyn C.; Genovesi, Piero; Jeschke, Jonathan M.; Kühn, Ingolf; Liebhold, Andrew M.; Mandrak, Nicholas E.; Meyerson, Laura A.; Pauchard, Aníbal; Pergl, Jan; Roy, Helen E.; Seebens, Hanno; Van Kleunen, Mark; Vila, Montserrat; Wingfield, Michael J.; Richardson, David M.
Biological invasions are a global consequence of an increasingly connected world and the rise in human population size. The numbers of invasive alien species – the subset of alien species that spread widely in areas where they are not native, affecting the environment or human livelihoods – are increasing. Synergies with other global changes are exacerbating current invasions and facilitating new ones, thereby escalating the extent and impacts of invaders. Invasions have complex and often immense long-term direct and indirect impacts. In many cases, such impacts become apparent or problematic only when invaders are well established and have large ranges. Invasive alien species break down biogeographic realms, affect native species richness and abundance, increase the risk of native species extinction, affect the genetic composition of native populations, change native animal behaviour, alter phylogenetic diversity across communities, and modify trophic networks. Many invasive alien species also change ecosystem functioning and the delivery of ecosystem services by altering nutrient and contaminant cycling, hydrology, habitat structure, and disturbance regimes. These biodiversity and ecosystem impacts are accelerating and will increase further in the future. Scientific evidence has identified policy strategies to reduce future invasions, but these strategies are often insufficiently implemented. For some nations, notably Australia and New Zealand, biosecurity has become a national priority. There have been long-term successes, such as eradication of rats and cats on increasingly large islands and biological control of weeds across continental areas. However, in many countries, invasions receive little attention. Improved international cooperation is crucial to reduce the impacts of invasive alien species on biodiversity, ecosystem services, and human livelihoods. Countries can strengthen their biosecurity regulations to implement and enforce more effective management strategies that should also address other global changes that interact with invasions.
Trait positions for elevated invasiveness in adaptive ecological networks
(Springer, 2021) Hui, Cang; Richardson, David M.; Landi, Pietro; Minoarivelo, Henintsoa O.; Roy, Helen E.; Latombe, Guillaume; Jing, Xin; CaraDonna, Paul J.; Gravel, Dominique; Beckage, Brian; Molofsky, Jane
Our ability to predict the outcome of invasion declines rapidly as non-native species progress through intertwined ecological barriers to establish and spread in recipient ecosystems. This is largely due to the lack of systemic knowledge on key processes at play as species establish self-sustaining populations within the invaded range. To address this knowledge gap, we present a mathematical model that captures the eco-evolutionary dynamics of native and non-native species interacting within an ecological network. The model is derived from continuous-trait evolutionary game theory (i.e., Adaptive Dynamics) and its associated concept of invasion fitness which depicts dynamic demographic performance that is both trait mediated and density dependent. Our approach allows us to explore how multiple resident and non-native species coevolve to reshape invasion performance, or more precisely invasiveness, over trait space. The model clarifies the role of specific traits in enabling non-native species to occupy realised opportunistic niches. It also elucidates the direction and speed of both ecological and evolutionary dynamics of residing species (natives or non-natives) in the recipient network under different levels of propagule pressure. The versatility of the model is demonstrated using four examples that correspond to the invasion of (i) a horizontal competitive community; (ii) a bipartite mutualistic network; (iii) a bipartite antagonistic network; and (iv) a multi-trophic food web. We identified a cohesive trait strategy that enables the success and establishment of non-native species to possess high invasiveness. Specifically, we find that a non-native species can achieve high levels of invasiveness by possessing traits that overlap with those of its facilitators (and mutualists), which enhances the benefits accrued from positive interactions, and by possessing traits outside the range of those of antagonists, which mitigates the costs accrued from negative interactions. This ‘central-to-reap, edge-to-elude’ trait strategy therefore describes the strategic trait positions of non-native species to invade an ecological network. This model provides a theoretical platform for exploring invasion strategies in complex adaptive ecological networks.
Troubling travellers : are ecologically harmful alien species associated with particular introduction pathways?
(Pensoft Publishers, 2017) Pergl, Jan; Pysek, Petr; Bacher, Sven; Essl, Franz; Genovesi, Piero; Harrower, Colin A.; Hulme, Philip E.; Jeschke, Jonathan M.; Kenis, Marc; Kuhn, Ingolf; Perglova, Irena; Rabitsch, Wolfgang; Roques, Alain; Roy, David B.; Roy, Helen E.; Vila, Montserrat; Winter, Marten; Nentwig, Wolfgang
Prioritization of introduction pathways is seen as an important component of the management of biological invasions. We address whether established alien plants, mammals, freshwater fish and terrestrial invertebrates with known ecological impacts are associated with particular introduction pathways (release, escape, contaminant, stowaway, corridor and unaided). We used the information from the European alien species database DAISIE (www.europe-aliens.org) supplemented by the EASIN catalogue (European Alien Species Information Network), and expert knowledge. Plants introduced by the pathways release, corridor and unaided were disproportionately more likely to have ecological impacts than those introduced as contaminants. In contrast, impacts were not associated with particular introduction pathways for invertebrates, mammals or fish. Thus, while for plants management strategies should be targeted towards the appropriate pathways, for animals, management should focus on reducing the total number of taxa introduced, targeting those pathways responsible for high numbers of introductions. However, regardless of taxonomic group, having multiple introduction pathways increases the likelihood of the species having an ecological impact. This may simply reflect that species introduced by multiple pathways have high propagule pressure and so have a high probability of establishment. Clearly, patterns of invasion are determined by many interacting factors and management strategies should reflect this complexity.
A vision for global monitoring of biological invasions
(Elsevier Ltd., 2017) Latombe, Guillaume; Pysek, Petr; Jeschke, Jonathan M.; Blackburn, Tim M.; Bacher, Sven; Capinha, Cesar; Costello, Mark J.; Fernandez, Miguel; Gregory, Richard D.; Hobern, Donald; Hui, Cang; Jetz, Walter; Kumschick, Sabrina; McGrannachan, Chris; Pergl, Jan; Roy, Helen E.; Scalera, Riccardo; Squires, Zoe E.; Wilson, John R. U.; Winter, Marten; Genovesi, Piero; McGeoch, Melodie A.
ENGLISH ABSTRACT: Managing biological invasions relies on good global coverage of species distributions. Accurate information on alien species distributions, obtained from international policy and cross-border co-operation, is required to evaluate trans-boundary and trading partnership risks. However, a standardized approach for systematically monitoring alien species and tracking biological invasions is still lacking. This Perspective presents a vision for global observation and monitoring of biological invasions. We show how the architecture for tracking biological invasions is provided by a minimum information set of Essential Variables, global collaboration on data sharing and infrastructure, and strategic contributions by countries. We show how this novel, synthetic approach to an observation system for alien species provides a tangible and attainable solution to delivering the information needed to slow the rate of new incursions and reduce the impacts of invaders. We identify three Essential Variables for Invasion Monitoring; alien species occurrence, species alien status and alien species impact. We outline how delivery of thisminimum information set by joint, complementary contributions from countries and global community initiatives is possible. Country contributions are made feasible using a modular approach where all countries are able to participate and strategically build their contributions to a global information set over time. The vision we outline will deliver wide-ranging benefits to countries and international efforts to slow the rate of biological invasions and minimize their environmental impacts. These benefits will accrue over time as global coverage and information on alien species increases.

Browsing by Author "Roy, Helen E."

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