Identifying long-term climatic refugia for amphibians in a global hotspot of diversity

Background/Question/Methods

Climate change is shifting or is expected to shift the distribution and abundances of a variety of taxa. Amphibians, in particular, are likely to respond to altered temperature and precipitation patterns since it has been well-established that these environmental variables shape the current distributions of the group. Given the likelihood of such shifts, forward-looking conservation and management plans cannot focus solely on current habitat, but must also consider areas that are likely to offer long-term climatic refugia. Regions that are projected to act as refugia for a large number of vulnerable species are especially important to identify. We used expert opinion to select a group of amphibian species in the southeastern United States that are likely to be vulnerable to climate change. We then applied a suite of species distribution models to these species as a way to identify protected areas in the region that are projected to be important in 2050 under different CO₂emissions scenarios. Protected areas were prioritized based on the number of species projected to persist in the unit, and we weighted that by the number of consensus models showing climatic suitability for each species.

Results/Conclusions

Across all protected areas in the southeast, one or more models indicated approximately 60% of the units will maintain at least some climatically suitable habitat for focal species. Although almost 40% of selected species were from the coastal plain, only one protected area (among > 1500 in the southeastern US) was within those climatic refugia projected to be the most valuable (i.e., the top 5% of all identified). All other protected areas that ranked among the most valuable to long-term amphibian conservation were within the southern Appalachian region. These protected areas were largely on federal lands; however, some state properties in Tennessee and North Carolina did emerge as highly valuable for several focal species. Other research suggests the coastal plain is an area where the pace of climate change is likely to be rapid. Such findings, in conjunction with our work, suggest that biodiversity in the coastal plain ecoregion is likely to be exceptionally vulnerable to climate change. Many conservation opportunities exist for the high amphibian biodiversity that is present within the Appalachian Mountains; however, more creative solutions for enhancing the adaptive capacity to climate change may be required for coastal plain species.