Our group leverages empirical and omics-based approaches to elucidate when and how biological diversity at multiple scales regulates ecosystem functions. Using manipulative experiments in natural systems, our group aims to identify drivers that underlie the variability of diversity-ecosystem function relationships in nature. Our research extends beyond the traditional species-level dimension of diversity-function relationships by contributing to the recently emerging focus on within-species diversity. Our research focuses predominantly on plants and bacteria that regulate carbon cycles in lake, river, and riparian ecosystems. Much of our research assesses the trophic and non-trophic interactions linking plants and bacteria, and the cascading consequences of these interactions on carbon cycling. We apply our work towards understanding the interconnections among declining diversity, ecosystem functions, and global change.