Modeling exotic fraction to predict regions with high potential of plant invasion.

Abstract Invasive plant species contribute to alteration of ecosystem functioning, reduction of native diversity, and have negative effects on numerous ecosystem services. Increases in anthropogenic regional connectivity is effectively intensifying establishment of self-sustaining populations of invasive plants around the globe. However, some ecosystems are disproportionately susceptible to incoming species. In this study, we used a recently compiled global data set of invasive plant distributions to calculate exotic fraction and estimate regional invasibility on a global scale. We found islands in Australasia to have the highest potential for future plant invasions. An appropriate invasibility metric, as the one developed here, has been largely lacking from invasive species studies despite its potential to guide effective, pre-emptive strategies for invasion prevention. We suggest that this tool is used as an efficient method to determine regions of greatest priority and opportunity for successful mitigation of threats from invasion.