Microorganisms (Bacteria, Archaea and Fungi) are the gate-keepers of many ecosystem-scale biogeochemical cycles. Although there have been measurable changes in ecosystem function due to human activities such as greenhouse gas production, nutrient loading, land-use change, and water consumption, few studies have connected microbial community dynamics with these changes in ecosystem function. Specifically, very little is known about how global changes will induce important functional changes in microbial biodiversity. Even less is known about how microbial functional changes could alter rates of nutrient cycling or whether microbial communities have enough functional redundancy that changes will have little impact on overall process rates. The proposed symposium will provide an overview of this emerging research area, with emphasis on linking the microorganisms directly to important ecological functions under the influence of global change dynamics. The session will include both broad overviews as well as specific case-studies by researchers who examine microbial communities from a variety of taxonomic levels and from various environments. The session will begin broadly, with speakers discussing how microbial communities may inform ecosystem-scale global change studies, and help to make microbial ecological knowledge more tangible for a broad range of ecologists. The session will continue with case studies of microbial community information informing process in global change experiments. Finally, the session will close with speakers discussing how microbial community information might fit into global change models, and what types of information are useful for future studies. We have requested that speakers particularly incorporate their views on what types of microbial data is useful and informative in the context of larger ecosystem processes. We foresee that this session could serve as a focal point for global change microbial ecologists to meet and discuss their field at the ESA 2010 General Meeting. However, more importantly, the session will provide for a broad range of interests for ecosystem ecologists, theoretical ecologists, and global change biologists, and will foster communication between these groups to generate informative microbial community data in the future. The session will consist of eight 15-minute presentations with 5 minutes for questions between each oral presentation. The final 30 minutes of the session will consist of a panel discussion involving interactive discussion between the speakers and the audience. The results of this panel discussion, as well as highlights from the oral presentations will be proposed to “Frontiers in Ecology and the Environment” as a review article or special issue for publication.