Predator Diversity and Thermal Niche Complementarity Attenuate Indirect Effects of Warming on Prey Survival.

AbstractClimate warming has broad-reaching effects on communities. Although much research has focused on direct abiotic effects, indirect effects of warming mediated through biotic interactions can be of equal or greater magnitude. A body of theoretical and empirical work has developed examining the effects of climate warming on predator-prey interactions, but most studies have focused on single predator and prey species. We develop a model with multiple predator species using simulated and measured realized thermal niches from a community of ants to examine the influence of predator diversity and other community thermal traits on the indirect effects of climate warming on prey survival probability. We find that predator diversity attenuates the indirect effect of climate warming on prey survival probability and that sufficient variation of predator thermal optima, closer prey and mean predator thermal optima, and higher predator niche complementarity increases the attenuation effect of predator diversity. We therefore predict that more diverse and complementary communities are likely more affected by direct versus indirect effects of climate warming, and vice versa for less diverse and complementary communities. If general, these predictions could lessen the difficulty of predicting the effects of climate warming on a focal species of interest.