Global climate change is recognized as a major threat to biodiversity, particularly to animals with significant physiological constraints or limited dispersal abilities. The Southern Appalachian region is a global hotspot for plethodontid salamander diversity. Plethodontid salamanders are adapted to cool, moist climates, and their diversity is tied to mountainous topography and precipitation in the region. Recent evidence indicates many of the dominant plethodontid fauna in the Southern Appalachian exists today at its thermal maximum, suggesting many species may be vulnerable to extirpation from projected climate change in the region. We applied climate envelope models to the species distribution modeling algorithm “maximum entropy” (program MaxEnt) to eight plethodontid salamander species. We evaluated the relative change in potentially suitable habitat for eight species in the southern Appalachian mountains from current climate to the years 2020, 2050, and 2080, using both low and high CO2 climate model scenarios.
Results/Conclusions
For all eight species, models project a decline in suitable habitat associated with climate change scenarios. Locally dominant species currently restricted to the montane regions, such as Desmognathus quadramaculatus, have a 100% loss of suitable habitat by 2080; whereas species found in both montane and piedmont regions (e.g. Gyrinophilus porphyriticus) are predicted to have an 80% loss of habitat and become restricted to the highland regions. Lastly, Desmognathus fuscus, a piedmont species, has a smaller (12%) predicted suitable habitat loss but shifts its distribution to the highland and coastal regions. Declines in suitable habitat would be exacerbated by limited dispersal capabilities of plethodontids and could lead to a risk of extirpation of many currently abundant and widespread plethodontid species in the Appalachian highlands. Our results project significant risk for plethodontids in Southern Appalachia. Since plethodontids exhibit high diversity in the region and are significant in a number of ecosystem processes, these projections identify a significant risk to global salamander diversity and associated change in ecosystem function.
