Meeting Abstract
As climate change and sea ice melt continue to progress, associative tidal and atmospheric patterns will increase the probability of extreme weather events, including drought and heat wave, at mid latitudes. The physiology of lungless terrestrial salamanders, in the genus Plethodon, makes them extremely sensitive to fluctuations in moisture availability; while their high abundance, small territory size, and ecological role as midlevel vertebrate predators make them excellent indicators of biodiversity, ecosystem integrity, and long term forest health. In this study we investigated the effect of drought and consequential intraspecific competition on the foraging success of P. cinereus, a species of Plethodon native to eastern North American forests. To investigate how the frequency of rain events influences salamander survivorship, we examined the density dependent relationship between moisture and individual foraging success (percent change in mass). To do so we manipulated soil moisture and population density under quasi-natural conditions in a lab based ecological experiment. Salamanders were randomly assigned to enclosures of different soil moisture and population density for each trial, and fluorescently tagged for identification. Trials consisted of a week-long acclimation period, leading up to a 48-hour period of competition following a feeding event. We predicted that foraging success is positively related to total rainfall. Moisture mediated pulses of food availability and intraspecific competition will compound this effect, so that salamanders exposed to dry conditions and high densities will exhibit the lowest fitness. By identifying the effect of prolonged drought in natural salamander populations our results will contribute to the ecogeography of eastern North American forests in the face of global climate change.
