Non-random interspecific variation in thermal sensitivities can increase or decrease the stability of model food webs
Andrea Tabi, Ferenc Jordan, Frank Pennekamp, Owen L. Petchey
The effects of temperature on food web stability can be explored using multispecies population dynamic models in which biological rates depend on temperature. A common assumption of these models is of no interspecific variation in this dependence. We explored how interspecific variation in thermal sensitivities affects the stability of complex communities. A set of model food webs varying in species richness and connectance were generated and were simulated in temperatures from 5 to 40°C. In the absence of interspecific variation in thermal sensitivities, increasing temperature decreased the number of species persisting. The presence of interspecific variation in thermal sensitivities qualitatively changed the effect of temperature on stability, with the type of change depending on features of the interspecific variation, such as its correlation with trophic level. These findings should motivate greater empirical and mechanistic investigation of the nature of interspecific variation in thermal responses.