LTER Cross-Site: Bacterial Community Composition and Dissolved Organic Matter in Streams: A Cross Site Comparison

Kent State University, Kent OH

Investigators

Abstract

PI: Leff, Laura DEB-0087051 "Bacterial community composition and dissolved organic matter in streams: a cross site comparison" Information about bacterial community taxonomic composition and population ecology is generally lacking. This study will identify and compare bacterial community composition among streams with different amounts and sources of dissolved organic matter (DOM). The PI hypothesizes that streams that differ in the source of DOM will have different bacterial community composition and that experimental exposure of bacteria from different streams to different types of DOM can profoundly affect the bacterial community of streams and that bacteria differ in their responses to different DOM mixtures. The project has two components: a field survey and lab experiments. Field work will be used to demonstrate the breadth of bacterial diversity and the differences among streams. Experiments will be used to demonstrate of DOM differences caused the patterns observed in the streams. The field survey will be done in 11 streams: six at LTER sites (Konza, Kellog, Coweeta, and North Temperate Lakes) and the others selected based on their DOM features. This study will allow the addition of bacterial diversity information to the LTER information base and answer basic questions about factors that control microbial diversity. Methodological limitations that have forced ecologists, in many situations, to "black box" bacterial communities will be overcome by this are and related work. This lays the groundwork for other fundamental questions about the role diversity plays in ecosystem function and the degree to which it is imperiled by human activities.