Microbial populations are vital to interactions in the ecosystem; however, it is difficult to predict how microbial communities and populations vary in response to environmental change. We are investigating changes in the community and population dynamics in the genus Streptomyces within the rhizosphere under long-term nitrogen addition as a model of how environmental changes impact microbial communities across scales. These long-term nitrogen addition sites (W.K. Kellogg Biological Station Long-term Ecological Research) provide a context in which to observe microbial evolution in the rhizosphere across scales, in response to nitrogen addition at levels comparable to agricultural fertilization. GEMS graduate student Isabelle Lakis will work with Rachel Whitaker, Katy Heath, and other members of the GEMS community to investigate the population structure and dynamics of environmental Streptomyces across scales. They hypothesize that long-term nitrogen deposition and plant association both diverge Streptomyces communities and populations and cause variation in Streptomyces pangenomic elements, including natural products.