Coevolutionary Consequences of Biodiversity Change

Anthropogenic global change is reshaping planetary biodiversity patterns at an accelerating rate. The diverse and non-linear ways in which species respond to global change can lead to non-obvious alterations in the structure and intensity of species interactions. However, the extent to which coevolutionary dynamics are disrupted under biodiversity change remains largely unknown. Interspecific interactions are the key determinants of biodiversity and ecosystem functioning, and their modifications can play a critical role in modulating global change effects on ecosystems. In this proposal I focus on plant-microbe associations to uncover how temporal change in plant communities affects interactions with mutualistic and pathogenic microbes both above- and below-ground. By coupling analysis of plant biodiversity time-series data with contemporary sampling of microbial communities, experiments and molecular assays, this work will demonstrate how both ecological and coevolutionary dynamics of species interactions are responding to ongoing environmental change. Specifically, I will answer the following key questions: 1) How has forest understory vegetation changed in response to changing climate and habitat use over 35 years; 2) How does temporal plant community change affect plant-associated microbial communities; 3) How have the intensity and efficacy of mutualistic and pathogenic host-microbe interactions changed; 4) How is coevolutionary selection, measured as local adaptation, altered following biodiversity change; 5) How do ecological and coevolutionary change underpinning species interactions scale up to ecosystem functioning in plant-microbe communities. The obtained results will reveal how vulnerable both pathogenic and essential mutualistic associations are to global anthropogenic change. Jointly the proposed research provides synthesis of the relative importance of ecological, evolutionary and environmental dimensions of biodiversity change.