Meeting Abstract
Forecasting species’ responses to impending climatic change remains one of the most preeminent challenges for conservation science. Characterizing species’ thermal performance curves has allowed us to mechanistically predict the effect of future warming on species’ persistence. However, considerable changes to hydrologic regimes are also expected to occur in tandem with warming. Water stress, or the hydration state of an organism, is also known to be a limiting factor for many species, but our understanding of how performance changes with hydration state is still limited. Evidence also suggests that hydration state may potentially interact with body temperature to dictate performance, which could substantially alter estimates of species’ vulnerability to future environmental change. Here, we assess the role of hydration state and temperature acting concurrently to dictate performance across six phylogenetically diverse amphibian species. We empirically tested: 1) the relative impacts of temperature and hydration on species’ performance, 2) whether hydration state changes the shape of thermal performance curves, and 3) how combining both environmental axes changes estimates of species’ climate risk. We show that hydration state has a strong negative effect on organismal performance, that it interacts with temperature for several species, and that integrating both hydration and temperature have the potential to affect estimates of species’ climate risk. As most hydrologic regimes are forecast to change with climate change, our results suggest that an integrative physiological approach combining both hydration and temperature as environmental drivers of fitness will improve estimates of extinction risk under future climate change scenarios.
