Meeting Abstract
Understanding species responses to climate change has become a top priority for conservation biologists. Unfortunately, current models often treat species as a single entity, ignoring population-level variation. This is a major problem when managing widespread species, which often exhibit physiological variation across their geographic range. Lungless salamanders are especially vulnerable to climate change, due to their dispersal limitations and dependence on cool, moist conditions for survival. The eastern red-backed salamander (Plethodon cinereus) is a widely-distributed lungless salamander composed of six mtDNA clades, which differ in their climatic niches. Here, I compared the relative effects of environmental temperature and phylogenetic history on thermal traits in P. cinereus. Specifically, I measured critical thermal limits and thermal performance in thirteen populations representing three phylogenetic clades across the species’ range. I found a strong phylogenetic signal in critical thermal limits, but not in thermal performance. Thermal performance was mostly driven by environmental temperatures at the population localities and conformed to the “hotter is better” hypothesis (i.e., salamanders from warm populations had higher thermal optima and performed better than salamanders from cool populations). My results shed light on the relative importance of environmental temperatures and evolutionary history on individual physiology. When integrated with population ecology, physiological traits can be used to better predict population viability in the face of climate change. Thus, understanding the physiology of widespread species provides a window into the past and a model for the future.
