Climate invader or refugee? Evaluating ecological impacts of species redistribution
Cascade Sorte
Department of Ecology & Evolutionary Biology, University of California, Irvine, USA
Shifts in species distributions was one of the first recognized “fingerprints” of climate change effects on natural ecosystems, and range shifts have now been documented for hundreds of species across virtually all taxa and ecosystems. While redistribution may be a climate change “coping mechanism” for some species, the spread of non-native species can also be problematic because of negative impacts on recipient communities. In fact, these impacts of shifting native species can be similar in direction and magnitude to those of non-native species invasions. Given that both climate change and invasive species are primary drivers of global biodiversity loss, this means that the redistribution of native species can drive cascading impacts of climate change. Range shifting species are likely to have greater impacts when they (1) share resources (compete) with, use as resources (consume), or become (prey) resources for species in the recipient community, (2) co-occur spatially with potentially interacting species, and (3) have strong interaction strengths as compared to native inhabitants. I use results of a meta-analysis and local case studies to illustrate how understanding resource use, spatial overlap and interaction strength could be used to predict whether the outcome of a species’ redistribution is more similar to peaceful coexistence or hostile takeover.