SS2.02 Biogeochemical Process at the Sediment-Water Interfaces
Date: Tuesday, June 11, 2002
Time: 11:00:00 AM
Location: Carson B
 
FindlayS, Inst. of Ecosystem Studies, Millbrook, USA, findlays@ecostudies.org
Sinsabaugh, R, L, University of Toledo, Toledo, USA, rsinsab@uoft02.utoledo.edu
Hoostal, M, , University of Toledo, Toledo, USA, mhoostal@uoft02.utoledo.edu
 
LINKING MICROBIAL COMMUNITY STRUCTURE, FUNCTION AND METABOLISM TO DOM
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The organization and metabolism of heterotrophic microbial communities is modulated by DOM source dynamics. We investigated these interactions along hyporheic pathways, correlating bacterial respiration R, production (BP), ectoenzyme activity (EEA), and community structure (RAPD) responses to DOM manipulations in a series of microcosm, mesocosm and field experiments. In one experiment, additions of tannin and glucose-BSA to influent DOM, boosted BP up to 4X in one system, but doubled R in another. In both, tannin addition increased community diversity. In another experiment, DON additions had larger effects on BP, R and DOM consumption than DIN. Across experiments, EEA responses were consistent with results from pelagic systems, diversity increased with apparent DOM complexity, and seasonal patterns were evident. The character of dominant inputs and 'pre-adaptation' are principal determinants of response magnitude, and processing efficiency.