The EICAT+ framework enables classification of positive impacts of alien taxa on native biodiversity

Abstract

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 instance, through food and habitat provisioning or dispersal facilitation) but there is currently no standardized and evidence-based system to classify positive impacts. We fill this gap by proposing EICAT+, which uses 5 semiquantitative scenarios to categorize the magnitude of positive impacts, and describes underlying mechanisms. EICAT+ can be applied to all alien taxa at different spatial and organizational scales. The application of EICAT+ expands our understanding of the consequences of biological invasions and can inform conservation decisions.

Threats of invasive alien species to Nature’s Contribution to People

“…While IAS may themselves provide NCP such as food, timber, protection against soil erosion and water puri cation, we limited our analysis to negative impacts because we focus on a set of IAS that are prioritised for management in Europe, which means that their deleterious impacts are considered to far outweigh any bene cial outcome. In addition, bene ts of IAS are not yet systematically reviewed in risk assessments 18 . In the future, the systematic description and evaluation of bene ts provided by IAS on NCP can help to identify con icts of interests and advance dialogue among stakeholders 19 .…”

How science communications can help build societal perceptions of invasive alien species and their impacts on the environment

“…An IAS having a positive impact on one organism does not necessarily mean that it will be beneficial to others (Vimercati et al 2022). However, using IAS to improve human livelihoods often ignores the requirements of a broad spectrum of other life forms that are directly or indirectly affected by the IAS.…”

“…While value judgements can be placed in the discussion sections of articles (e.g., Jachuła et al 2019), a dedicated section for such judgements might be more effective in terms of drawing readers' attention. Importantly, this section should not be viewed as representing a caveat of the study; instead, the value judgements of the authors should complement the study's findings to provide a more complete pictures of the IAS in question (Vimercati et al 2022). Journal editors and reviewers should also encourage authors' engagement with this practice.…”

“…Multiple attempts have been made to consider the beneficial effects of some IAS in order to make better regulatory decisions. For example, the Environmental Impact Classification for Alien Taxa (EICATþ) framework has been proposed to categorize the magnitude of such positive impacts (Vimercati et al 2022), whereas the Risk Analysis for Alien Taxa (RAAT) framework includes beneficial impacts as one of the criteria for the risk management of alien taxa (Kumschick et al 2020). Ideally, the trade-offs between the overall costs and benefits of IAS on sustainable livelihoods (i.e., livelihoods that can cope with economic, environmental and social stresses and maintain or enhance their capabilities and assets both now and in the future while not undermining natural resource bases; DFID 2000) should be integrated into IAS-specific studies (Shackleton et al 2019).…”

Editorial: Biological invaders: Always the bad guys?

“…Invasive species are recognized as one of the major environmental problems worldwide and responsible for a myriad of impacts on ecosystems and ecosystem processes. Although many invasive species exert a range of detrimental effects a more nuanced approach is now emerging, which acknowledges that they can make a positive or beneficial contribution (Schlaepfer et al, 2011;Vimercati et al, 2020Vimercati et al, , 2022Mantoani et al, 2022). Clearly, a positive impact may not always be beneficial (Vimercati et al, 2022) and nutrient enrichment due the introduction of an alien nitrogen-fixing plant species, for instance, could result in the loss of important resident species with low nutrient requirements.…”