Climate mediates geographic patterns in ecoevolutionary plant-soil dynamics

Unifying ecosystem ecology and evolutionary biology promises a more complete understanding of the processes that link different levels of biological organization across space and time. Feedbacks across levels of organization link theory associated with eco-evolutionary dynamics, niche construction, and the geographic mosaic theory of co-evolution. The work presented in this dissertation directly extends the integration of eco-evolutionary dynamics by 1) highlighting our current knowledge of eco-evolutionary feedbacks in ecosystems, to provide an improved synthesis and foundation for understanding the interplay between biodiversity and ecosystem function through an eco-evolutionary lens; 2) examining the hypothesis that climate-driven evolution of plant traits will have downstream consequences for associated soil microbiomes and ecosystem function across the landscape; and 3) examining genetically-based plant-soil feedback at the landscape scale to understand how variation in climate, soil microbiome function, and tree-driven soil conditioning interact to influence phenotypic variation in bud break phenology. The findings from this dissertation provides evidence that understanding the natural variation in genetic components of both above- and belowground portions of the plant-soil linkage are important for predicting patterns of divergence in ecosystem function in a warmer world. Cumulatively, this dissertation extends the field of eco-evolutionary dynamics by highlighting the interplay between ecology and evolution that governs the expression of phenotypes, patterns of community composition, and divergence in ecosystem function at spatial scales rarely appreciated.