Moving from Micro to Macro: Scaling Interactions Between Organisms and Microclimates to Predict Species Ranges

Michael Sears, PhD

Department of Biological Sciences
Clemson University

Predicting the dynamics of species ranges in response to ongoing climatic change has become a top concern of biologists. Process-based modeling approaches that incorporate physiological and behavioral mechanisms are rapidly becoming powerful tools to make such predictions. Key to these approaches is understanding the biophysical constraints on activity budgets. Typically, such models assume an all-or-nothing approach where, as long as environmental temperatures overlap individual preferences, all individuals in a population are active and accrue (or lose) energy from the environment. Due to the thermal heterogeneity of many environments, responses of activity by all individuals are not possible. Here, I demonstrate how activity patterns can be generated by the movements of individuals under thermoregulatory constraint and how these models predict activity similar to that observed in natural populations. Further, results will be contrasted with those predicted by other modeling approaches to note the potential pitfalls when small-scale environmental heterogeneity is not considered.