This is a Dimensions of Biodiversity project that is collaborative with Sharon Strauss at UC Davis, funded by the National Science Foundation.
Understanding how species coexist, and the role of genetic diversity within and between species, remains a fundamental challenge in biodiversity research. This project focuses on highly diverse communities of clover plants and their bacterial nitrogen-fixing symbionts, rhizobia. Integrating observational approaches, manipulative field, greenhouse, and growth chamber experiments, genomic techniques and phylogenetic analyses, this project will test the importance of rhizobial symbionts and soil feedbacks in coexistence. Gene expression and functional traits will serve as proxies for the ecological niche; this project will determine how these evolve using phylogenetic trees that capture the evolutionary history of species. This project will yield an integrated insight into the molecular, functional, and ecological mechanisms of diversity maintenance and will greatly increase our understanding of biological nitrogen fixation, a critical function of legumes and rhizobia in natural and agricultural ecosystems.
Symbiotic nitrogen fixation has global importance on par with photosynthesis, and this project will assess its functionality in light of genetic variation in symbionts and clover species.