Topographic and vegetation drivers of thermal heterogeneity along the boreal–grassland transition zone in western Canada: implications for climate change refugia

Climate-change refugia are areas that are relatively buffered from contemporary climate change and may be important safe havens for wildlife and plants under anthropogenic climate change. Topographic variation is an important driver of thermal heterogeneity, but it is limited in relatively flat landscapes, such as the boreal plain and prairie regions of western Canada. Topographic variation within this region is mostly restricted to river valleys and hill systems, and their effects on local climates are not well documented. We sought to quantify thermal heterogeneity as a function of topography and vegetation cover within major valleys and hill systems across the boreal–grassland transition zone.
Using iButton data loggers, we monitored local temperature at four hill and 12 river valley systems that comprised a wide range of habitats and ecosystems in Alberta, Canada (N = 240) between 2014 and 2020. We then modelled monthly temperature by season as a function of topography and differen...