Roots play a key role in biogeochemical cycling, hydrologic patterns, and soil organic matter formation across terrestrial ecosystems. However, rhizosphere processes are sensitive to changing temperatures and hydrologic conditions, land use and land cover change, and other disturbances. Feedbacks between roots, root-associated microbes, and changing soil ecosystems could buffer or enhance biogeochemical responses and therefore present a critical avenue of research. Furthermore, many of these feedbacks have little to no representation in land surface models. Given the difficulties of studying and modeling roots, our understanding of roots and their role in biogeochemical cycles is still nascent. In this session, our goal is to synthesize our present understanding of root patterns and processes, their roles in biogeochemical cycles, and their responses to change and disturbance. We invite contributions that expand our understanding of root dynamics, root-associated microbes and processes, and that highlight crucial steps for the future of belowground research.