Can we now determine if, when, and how microbial community composition impacts ecosystem processes? Will that understanding yield critical new information about ecosystem function and response to change?

Linking populations and process dynamics has been a major thrust in ecology for the last decade or more. This issue has been a concern in microbial ecology, but linking microbial community dynamics with ecosystem scale processes has been a major challenge. There remains debate as to whether any such linkages really exist, though there are theories about which processes should be sensitive to community composition and there have been a number of individual studies that support these theories. There has not, however, been any broad and effective synthesis to test theories or critically assess how best to establish microbe-ecosystem linkages. We propose a working group that will identify the most successful current approaches for establishing linkages, work with available data sets and existing ecosystem models to determine how to best incorporate appropriate microbial community dynamics into larger-scale models, and work with the models to evaluate the effects of incorporating microbial dynamics into them.