RT Journal Article
SR Electronic
T1 Adaptation to warming increases the strength of an algal-grazer interaction in naturally heated streams
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 104513
DO 10.1101/104513
A1 C. -Elisa Schaum
A1 Richard Ffrench-Constant
A1 Chris Lowe
A1 Jón S. Ólafsson
A1 Daniel Padfield
A1 Gabriel Yvon-Durocher
YR 2017
UL http://biorxiv.org/content/early/2017/01/31/104513.abstract
AB Trophic interactions are important determinants of the structure and functioning of ecosystems. As the metabolism and consumption rates of ectotherms increase sharply with rising temperature, there are currently major concerns that global warming will increase the strength of trophic interactions, destabilizing food webs, and altering ecosystem structure and function. We used geothermally warmed streams that span a ~10 ºC temperature gradient to investigate the interplay between the thermal response of respiration, local adaptation, and the interaction strength between the keystone gastropod grazer, the wandering snail Radix balthica, and a common algal resource. Populations from a warm stream (~28ºC) had higher maximal metabolic rates and optimal temperatures across all measurement temperatures than those from a colder stream (~17ºC), suggesting local adaptation of metabolic rates. A reciprocal transplant experiment demonstrated that the interaction strength between the grazer and its resource were highest for both populations when transplanted into the warm stream. In line with the thermal response curves for respiration, interaction strengths of the warm-adapted grazers were higher than their cold-adapted counterparts in both the warm and the cold stream. These findings suggest that warming can increase the strength of algal-grazer interactions both through the thermodynamic effects of higher temperatures on physiological rates and through correlated increases in per capita metabolism and consumption as organisms adapt to warmer temperatures.