Assessing climate change effects on competitive interactions of the federally endangered Shenandoah salamander (Plethodon shenandoah)

Abstract

The Shenandoah salamander (Plethodon shenandoah) is a federally endangered species with a restricted distribution at high elevation in Shenandoah National Park, presumably limited by competition with the red-backed salamander (Plethodon cinereus). Recent research suggests that climate change may exacerbate interspecific competitive interactions at a cost to P. shenandoah. An effort to evaluate P. shenandoah extinction risk and management options identified uncertainties that must be addressed in order to make a management decision, including the response of P. shenandoah to climate change. I investigated the influence of climate on competitive interactions in 3- dimensional mesocosms that mimicked realistic habitats in two phases: (1) a pilot study to ensure the suitability of the experimental venue, and (2) a primary study to investigate the response of P. shenandoah to competition with P. cinereus under two future climate scenarios. The results suggest that core P. shenandoah populations may decline in response to increasing temperatures, particularly if their habitat is getting warmer and drier, though range expansion may occur in areas where it competes with P. cinereus.