Plant diversity has been studied extensively for its impact on a few basic measures, such as biomass production. However, relatively little is understood about interactions between plant diversity and microbial communities. Through removal of natural enemies with pesticide treatments, we found that foliar fungi have a significant impact on plant productivity, and that the impact is greater at higher than at lower plant diversity.

The MIRADA project was launched in the fall of 2007 to establish a Microbial Biodiversity Survey and Inventory across all 13 of the major aquatic (marine and freshwater) Long Term Ecological Research (LTER) sites in the NSF US LTER Program. The long-term objective of our study is to document and describe baseline diversity and relative abundance data for both common and rare members of microbial communities and to relate this diversity to the underlying physical and chemical environment.

Impact of Agricultural Practices on Bacterial Carbon Use Efficiency
Z. M. Lee and T. M. Schmidt
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI

Microorganisms have confounded biogeographers because of their high dispersal capability, small size, and vast diversity and abundance. Here we use pyrosequencing, bioinformatics tools, and geospatial modeling to reveal that the genetic relatedness of soil bacteria varies in a predictable pattern across a landscape. Microbial communities showed strong spatial autocorrelation to a distance of 240 meters and this pattern was driven by changes in the genetic relatedness and abundance of specific clades across the landscape.