Paleeo-ecological plant data reveal effects of climate-driven range shifts on community structure
Dr Regan Early1, Dr Dana Blumenthal, Dr Cascade Sorte, Ms Evelyn Beaury, Professor Deborah Goldberg
1University Of Exeter, Penryn, United Kingdom
Very little is known about how species shifting their geographic ranges will integrate with, or respond to, the ecological communities they encounter. Will ‘climate migrants’ behave like invasive species introduced between biogeographic regions in recent centuries and dominate or restructure ecological communities, and how will these effects change through time? Will climate migrant abundances be predicted by their abundances in their previous range? Will some ecological communities be more resistant than others to colonization by natural colonists?
We ask these questions using changes in the geographic range and abundance of plant taxa in 634 locations over 25 thousand years in north America.
We investigate changes in the abundances of climate migrants and taxa in the recipient communities immediately and longer after colonization. We pair these with modelled expectations of the climatic and geographic limitations on taxa abundances, in order to identify the relative role of climate change and colonization on taxa and ecological communities. We find that colonization by climate migrants reduces the Shannon’s diversity of recipient communities over the timescale of 500 years. Our results illustrate the complex role of biotic interactions in mediating range shifts and their ecological impacts.
Regan Early aims to disentangle the effects of abiotic and biotic drivers of species’ distributions, asking how this information can be used to improve biodiversity models, and forecasts of climate change and biological invasions. She works with a multitude of ecosystems, taxa, and geographic regions, using field and computational studies. Regan also seeks to apply fundamental biogeographic knowledge to conservation and crop pest management under climate change.