Background/Question/Methods As the world has warmed in the Anthropocene, species distributions have shifted, affecting ecosystems, economies, and human well-being. Yet inconsistencies among species’ responses challenges our ecological understanding of the processes governing biogeographic range dynamics. Here I present a suite of studies aimed at connecting physiological responses to spatial distributions, to improve how we understand and anticipate range shift dynamics among species. I ask, to what extent are species physiologically limited within their existing distributional ranges, do ranges shift accordingly, and finally, given its potential role, how is intraspecific competitive ability affected by warming as a function of species’ thermal performance?
Results/Conclusions I present results showing that geographic ranges are more directly defined by temperature tolerance in marine compared to terrestrial organisms, with nuances with regard to acclimation, thermoregulation, and local adaptation. Marine species’ ranges have been more responsive to climate warming compared to terrestrial species’ ranges, and marine species with broader ecological niches and higher motility have faster leading-edge range shifts. Finally, I present experimental findings to support a model in which competitive ability for resources varies unimodally with temperature but with a more pronounced leptokurtic functional responses compared to classic thermal performance curves. I combine these findings to explore implications on range dynamics driven by climate change.
