Vulnerability of high-elevation endemic salamanders to climate change: A case study with the Cow Knob Salamander (Plethodon punctatus)

Abstract

Rapid contemporary climate change is a potential threat to long-term persistence of montane wildlife species because they often have narrow thermal tolerances and have limited potential to shift their distributions. The Appalachian Mountain region in the eastern United States is a global biodiversity hotspot for woodland salamanders (genus Plethodon), many of which are high-elevation endemic species. Robust assessments of the vulnerability of high-elevation endemic salamanders to climate change, including delineation of future potential climate refugia, are needed to guide climate change adaptations strategies. The Cow Knob Salamander (Plethodon punctatus) is a species of conservation concern found at high elevations in the Valley and Ridge Province of western Virginia and eastern West Virginia. We used habitat suitability models to examine relationships between landscape characteristics, climate variables, and P. punctatus occurrence, and estimated effects of future climate scenarios on the species’ climatic niche. We found that elevation, slope, aspect, and hillshade were influential landscape predictors of species occurrence, and that mean annual temperature was the most influential climate variable. Future climate projections indicated this species will likely lose most of its climatic niche by mid-century, and that amount of suitable habitat will continue to decline through 2100. We identified several pockets of habitat that may represent climate change refugia for P. punctatus due to cooler microclimates from greater hillshade and aspects that receive less direct solar radiation; however, we found these refugia exist in small, isolated habitat patches. Our study provides quantitative estimates that support the general concern that high-elevation endemic salamanders are particularly vulnerable to climate change. Our models can be used by natural resource managers to guide current P. punctatus monitoring and habitat conservation efforts, as well as to identify focal areas that will likely serve as refugia for the species as the climate continues to change over this century.