Can we predict ectotherm responses to climate change using thermal performance curves and body temperatures?
Thermal performance curves (TPCs), which quantify how an ectotherm's body temperature (Tb) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate change. Here, we examine the key - but often biologically unreasonable - assumptions underlying this approach; for example, that physiology and thermal regimes are invariant over ontogeny, space and time, and also that TPCs are independent of previously experienced Tb.We show how a critical consideration of these assumptions can lead to biologically useful hypotheses and experimental designs. For example, rather than assuming that TPCs are fixed during ontogeny, one can measure TPCs for each major life stage and incorporate these into stage-specific ecological models to reveal the life stage most likely to be vulnerable to climate change. Our overall goal is to explicitly examine the assumptions underlying the integration of TPCs with Tb, to develop a framework within which empiricists can place their work within these limitations, and to facilitate the application of thermal physiology to understanding the biological implications of climate change.
Department of Biology, University of Western Ontario, London, ON, Canada. bsincla7@uwo.ca.
Brent J
BJ
Sinclair
Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
Katie E
KE
Marshall
School of Biological Sciences, University of Auckland, Auckland, New Zealand.
Mary A
MA
Sewell
Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia.
Danielle L
DL
Levesque
Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Christopher S
CS
Willett
Department of Bioscience, Aarhus University, Aarhus, Denmark.
Stine
S
Slotsbo
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
Yunwei
Y
Dong
Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
Christopher D G
CD
Harley
Faculty of Science, Universiti Brunei Darussalam, Gadong, Brunei Darussalam.
David J
DJ
Marshall
Department of Marine and Environmental Sciences and School of Public Policy and Urban Affairs, Northeastern University Marine Science Center, Nahant, MA, USA.
Brian S
BS
Helmuth
Department of Biology, University of Washington, Seattle, WA, USA.
Raymond B
RB
Huey
D000222:Adaptation, Physiological; D000818:Animals; D001833:Body Temperature Regulation; D057231:Climate Change; D004777:Environment; D008954:Models, Biological; D013997:Time Factors
Body temperature; climate change; fitness; thermal performance; thermal variability