Community structure is affected both by the nature and structure of species interactions and their interplay with the abiotic environment. Temperature in particular is known to affect ectotherms life history and interaction traits in predictable ways at the organismal level, but the effects of this on the community level is still poorly understood. With mounting evidence of climate change and temperature induced range shifts and extinctions, developing models that are able to predict how our communities will behave in current and future climatic scenarios is a high priority. Here I present a trait-based mathematical model for a three trophic food web, in which the effects of temperature are mechanistically incorporated through realistic trait temperature response curves. I test persistence of the model through analytical invasibility criteria, identifying the most relevant parameters for persistence and confirm these results with numerical simulations of the model. Through these analysis I seek to find which adaptations lead to a more stable community and how changes in temperature regimes can affect the persistence of these communities.
Results/Conclusions
Preliminary analysis suggests that a three trophic chain is more stable when its top predator is more warm adapted and more of a temperature specialist than the intermediate consumer. This confers an advantage when facing a warming scenario, since the limited high temperature range in which the predator is active is less likely to be lost with climate warming. However, warming does present a threat as it removes the lower temperature refuges for the lower trophic levels, leading to a decline in abundances that directly affects its predator. This is compounded with the fact that ectotherms experience higher mortality at higher temperatures, so that even if warming does not reduce the active thermal ranges of each species, it still increases the mortality they experience through their inactive periods, causing to higher drop in abundances at higher temperatures. Therefore, despite higher trophic levels having thermal ranges that are less likely to be lost, the cascading effects caused by warming by the lower trophic levels still pose a threat to these organisms.