Microclimate and its Role in Biogeography from Local to Global Scales

Klinges, David

ABSTRACT: Environments and societies face a legion of global change crises, including contemporary climate change that manifests as warmer, dryer, and more extreme conditions. While all species on earth experience climate change, biological responses to climate vary between species, and have proven hard to understand or predict in a general sense. One of the prominent factors leading to low predictability of such biological responses has been due to measuring of modeling climate that inadequately represents climate exposure as actually experienced by organisms. This is because much climate change research relies on climate data measured by weather stations placed away from trees and in flat terrain, yet most life on earth experiences microclimates influenced by topography, vegetation, and other local-scale abiotic and biotic drivers. Through this dissertation, I examined the importance of microclimate for understanding the distributions and diversity of species in space and time. I first interrogated a classic biogeographical hypothesis by synthesizing global data on mountain climates, and suggest that microclimate may play a more prominent role than macroclimate in determining how mountains limit species’ distributions. Then, I used several biological case studies with insects and amphibians to show that how well climate data represent organismal thermal exposure (i.e. “climate data proximity”), rather than data resolution per se, is more important for the accuracy of biological models.