10.6084/m9.figshare.4873151.v1
Yun-wei Dong
Yun-wei
Dong
Xiao-xu Li
Xiao-xu
Li
Francis M. P. Choi
Francis M. P.
Choi
Gray A. Williams
Gray A.
Williams
George N. Somero
George N.
Somero
Brian Helmuth
Brian
Helmuth
Electronic Supplementary Material from Untangling the roles of microclimate, behaviour and physiological polymorphism in governing vulnerability of intertidal snails to heat stress
The Royal Society
2017
climate change
heat budget model
microhabitat
physiological adaptation
species distribution
2017-04-13 13:33:07
Journal contribution
https://rs.figshare.com/articles/journal_contribution/Electronic_Supplementary_Material_from_Untangling_the_roles_of_microclimate_behaviour_and_physiological_polymorphism_in_governing_vulnerability_of_intertidal_snails_to_heat_stress/4873151
Biogeographic distributions are driven by cumulative effects of smaller scale processes. Thus, vulnerability of animals to thermal stress is the result of physiological sensitivities to body temperature (<i>T</i><sub>b</sub>), microclimatic conditions and behavioural thermoregulation. To understand interactions among these variables, we analysed the thermal tolerances of three species of intertidal snails from different latitudes along the Chinese coast, and estimated potential <i>T</i><sub>b</sub> in different microhabitats at each site. We then empirically determined the temperatures at which heart rate decreased sharply with rising temperature (Arrhenius breakpoint temperature, ABT) and at which it fell to zero (flat line temperature, FLT) to calculate thermal safety margins (TSM). Regular exceedance of FLT in sun-exposed microhabitats, a lethal effect, was predicted for only one mid-latitude site. However, ABTs of some individuals were exceeded at sun-exposed microhabitats in most sites, suggesting physiological impairment for snails with poor behavioural thermoregulation and revealing inter-individual variations (physiological polymorphism) of thermal limits. An autocorrelation analysis of <i>T</i><sub>b</sub> showed that predictability of extreme temperatures was lowest at the hottest sites, indicating that the effectiveness of behavioural thermoregulation is potentially lowest at these sites. These results illustrate the critical roles of mechanistic studies at small spatial scales when predicting effects of climate change.