Warming drives poleward range contractions of endemic species at high latitudes

Background/Question/Methods

Species are expected to disperse poleward in response to climate change. For species that are endemic to high latitudes, this implies that many in the future would face a “no-where-to-go” situation as they are currently occupying the northernmost edge of the continent. Further, because endemism may arise from a combination of physical barriers, climate, and geologic history, the persistence of many species may require spatial matching of two or more environmental factors within a limited dispersal space. Thus, it is not clear how these endemic species might spatially adjust their distributions to cope with climate change.We used ensemble bioclimatic models to evaluate drivers and directional patterns of future change in the distributions of 32 amphi-Beringian species (those found within northwest North America and northern Eurasia Beringia) in the Yukon. We also asked whether there are contemporary potential climate-change refugia that correspond with the spatial aggregation of endemic species across the region.

Results/Conclusions

More than 75% of the species showed northward shifts in their latitudinal centroids under intermediate warming and are expected to shift their range northward by more than 90 km on average by 2040. Additionally, more than 50% of the species could experience range contractions of 70% or more. Some species are projected to disappear from the Yukon by 2040 while some could expand their ranges by more than 100%.The suitable landscape for endemic species in the Yukon is expected to decline significantly, especially within the southern bounds of the Yukon Pleistocene refugium (Beringia), which is expected to be up to 20% warmer than areas of stable distributions, suggesting that the thermal characteristics that made the region a refugium during the glacial period could perhaps make it inhospitable for many species under a warming climate.