Decision tools for managing biological invasions: existing biases and future needs

Abstract

The increasing number of invasive species and their effects on wildlife conservation, together with a lack of public resources, make it necessary to prioritize management actions. In practice, management decisions are often reached on the basis of subjective reasoning rather than scientific evidence. To develop a more evidence-based and efficient management of biological invasions, decision tools (e.g. multi-criteria frameworks) that help managers prioritize actions most efficiently are key. In this paper we review to what degree such decision tools are currently available. We used a literature search to identify relevant studies. Our analysis indicates that available studies are largely biased towards risk analysis and that only a few authors have proposed cost-benefit or multi-criteria frameworks for decision making. Until now, these frameworks have only been applied at limited regional scales but they could be applied more widely. Our review also shows critical biases in the geographical focus, habitats, and taxonomic groups of available studies. Most studies have focused on Europe, North America or Australia; other continents have largely been ignored. The majority of studies have focused on terrestrial plants; other habitats and taxonomic groups have been poorly covered. Most studies have focused on a single invasive species but practical management tools should consider a wide variety of invaders. We conclude with suggestions for developing improved decision tools.

A Cost–Benefit Approach for Prioritizing Invasive Species

“…While well-developed and globally-applicable indicators and decision-support tools are still lacking (Dana et al, 2014), species prioritization is often grounded on the basis of invasive species watch lists, the best known being the IUCN GISD blacklist of the 100 worst invasive species worldwide, developed in the early 2000s.…”

“…As argued by Dana et al (2014), despite the advancements achieved, the practical use of existing decision tools has often been limited and may be misleading as they typically ignore economic, social, technical, institutional or political factors related to conservation and management practices. In particular, as noted by Koch et al (2016), managing and monitoring is quite costly and decisions thus need to be made on a sound basis to avoid wasting resources.…”

“…Many papers also focus on optimal surveillance and detection strategies to limit the spread of a single invasive species with papers including Hauser and McCarthy (2009);McCarthy et al (2008); Epanchin-Niell et al (2014) and Holden et al (2016). As Dana et al (2014), the review by EpanchinNiell (2017) shows that only one cost-benefit optimization paper addresses the question of species prioritization by assessing allocation choices among multiple invasions.…”

“…9 In a review based on ISI web of science, Dana et al (2014) report that among 43 relevant research papers on invasive species prioritization, only two are based on a cost-benefit optimization modeling, most of the remaining being risk analysis ranking species on the basis of impacts and/or invasiveness. Among the two cost-benefit optimization papers discussed, only Carrasco et al (2010) studies species prioritization by assessing allocation choices among multiple invasions.…”

“…Echoing the increasing demand for simple tools that guide managers and politicians to optimize their investments based on objective and measurable criteria (Tilman, 2000;Roura-Pascual et al, 2009;Dana et al, 2014;Koch et al, 2016), we define the theoretical groundwork of a general ranking formula that could be used as a rule of thumb in order to design a reliable, easy to apply, and economically sound tool to derive management decisions. The paper proceeds as follows.…”