October 22 2014

12:00 2320 Life Sciences B

Franck Courchamp
Department of Ecology and Evolutionary Biology and the Institute of Environment and Sustainability, UCLA and the CNRS, University of Paris South, France

Interactions between climate change and biological invasions


Biological invasion and climate change are increasingly recognized as being among the greatest threats to biodiversity. There is general consensus that the distributions of invasive species are likely to expand with climate change; however this common assumption remains untested. Here we model suitable area globally for two large samples of some of the worst invasive species, both currently and with predicted climate change (in 2080), globally, regionally and within the world’s 34 biodiversity hotspots. Our first sample is taxonomically and ecology very large, and serves to provide an overall pattern of relationships between these two global drivers: all the species of the infamous “100 of the world’s worst alien invasive species” IUCN list. Our second sample is focused on 15 species of one single family with homogeneous ecological traits, ants, and serves to show that our findings hold even within a relatively small set of similar species. Using ensemble forecasts from species distribution models to project future suitable areas of invasive species, we show that climate change will likely cause drastic shifts of potential range of invasive species. Looking at potential spatial aggregation of invasive species, we also identify several future hotspots of invasion. Surprisingly, we also show that, in both cases, the potential distribution of only some species is predicted to increase with climate change, with many others declining. Similarly, some regions will gain invasive species, but others will lose some, and the changes will not simply amount to a shift poleward. Contrarily to general expectations, climate change and biological invasions will not systematically act synergistically. However, alien invasions will likely remain a major global problem, especially where invasion hotspots coincide with biodiversity hotspots.











































































































































































































































































































































































































































































































































































































this is idtest: