Alien plant species with a wider global distribution are better able to capitalize on increased resource availability

Abstract

A high ability of alien plant species to capitalize on increases in resource availability has been suggested as an explanation for being globally successful. Here, we tested this hypothesis meta-analytically using existing data from experiments manipulating plant resources (light, water and nutrients). From these studies we extracted the response to resource increase of biomass, as an indicator of plant performance, and the responses of two traits related to resource capture: root:shoot ratio and specific leaf area (SLA). For 211 species recorded in the Global Compendium of Weeds, we assessed the relationship between effect sizes from such studies and the number of global regions where a species was established. We found that globally widespread species exhibited greater biomass responses to increases in resources overall, compared to less widespread species. Root:shoot ratio and SLA responses to increased resource availability were not related to species global distribution. In general, globally widespread alien plant species were better able to capitalize on increased availability of resources, through achieving increased growth and biomass accumulation, while greater plasticity of key resource-capture traits per se did not appear to be related to greater success. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.