Meeting Abstract

S9-1.3  Monday, Jan. 7  Body temperatures along altitudinal and latitudinal gradients: interactions between phenotypes and multiple environmental stressors BUCKLEY, Lauren B.; Univ. of North Carolina, Chapel Hill buckley@bio.unc.edu

The divergence between body and air temperatures is central to patterns of thermal stress associated with climate change. We use biophysical models to estimate body temperatures as a function of an organism’s phenotype and environmental conditions (air and surface temperatures and radiation). Using alpine butterflies as a case study, we compare mean body temperatures and the incidence of thermal extremes along altitudinal gradients in both past and current climates. Organisms at higher elevation can experience more frequent thermal stress events despite generally cooler air temperatures due to high levels of solar radiation. Incidences of thermal stress events have increased more rapidly than increases in mean conditions due to recent climate change. Increases in air temperature have coincided with increased cloudiness with complex consequences for altitudinal patterns of thermal stress. We compare altitudinal trends, including seasonal overlap, between tropical and temperate mountains to ask whether mountain passes are higher in the tropics (Janzen’s hypothesis) when considering body rather than air temperatures. Our analysis highlights the potential fallacy of predicting thermal stress based solely on air temperatures and the importance of considering phenotype-environment interactions.