Meeting Abstract

83-5   14:30 - 14:45  Acute effects of temperature confound estimates of acclimation capacity of critical thermal maximum with consequences for vulnerability assessments Cicchino, AS*; Shah, AA; Forester, BR; Dunham, JB; Landguth, EL; Poff, NLR; Ghalambor, CK; Funk, WC; Colorado State University, Fort Collins, CO; Kellogg Biological Station at Michigan State University, Hickory Corners, MI; Colorado State University, Fort Collins, CO; USGS, Forest and Rangeland Ecosystem Science Center, Corvallis, OR; University of Montana, Missoula, MT; Colorado State University, Fort Collins, CO; Norwegian University of Science and Technology, Trondheim, Norway; Colorado State University, Fort Collins, CO cicchino@colostate.edu https://amandascicchino.weebly.com/

Adaptive plasticity in thermal tolerance traits may buffer organisms against changing thermal regimes and is of increasing interest in the face of global climate change. A challenge to quantifying this plasticity arises from acute (immediate) and acclimated (longer-term) physiological responses to temperature. The relative contributions of these responses to estimates of acclimation capacity of critical thermal limits remains unclear yet key for accurate vulnerability assessments. Here, we contrast acute versus acclimated effects of temperature on estimates of acclimation capacity and vulnerability. Via temperature ramping, we estimated critical thermal maximum temperature (CTmax) for 14 populations of tailed frogs (family: Ascaphidae) using a fully factorial design of two acclimation and two start temperature treatments. These experiments revealed substantial variation among populations in both acute and acclimated effects of temperature on CTmax. Although species-level conclusions regarding acclimation capacity did not change after accounting for acute effects, ignoring these effects led to the misrepresentation of population vulnerability to site-specific projected temperature increases. These results to date suggest there may be substantial variation in thermal sensitivity among populations and that such variation may be critical when assessing the implications of warming conditions on vulnerability.