HR: 1330h
AN: NB33C-01    [Abstracts]
TI: Nitrogenase and Alkaline Phosphatase Activity in Wetland Metaphyton: Implications for Primary Production and CNP Composition
AU: * Scott, T
EM: Thad_Scott@baylor.edu
AF: Center for Reservoir and Aquatic Systems Research Department of Biology Baylor University, One Bear Place #97388, Waco, TX 76798 United States
AU: Doyle, R
EM: Robert_Doyle@baylor.edu
AF: Center for Reservoir and Aquatic Systems Research Department of Biology Baylor University, One Bear Place #97388, Waco, TX 76798 United States
AB: Longitudinal gradients of nutrient availability often occur along the flow path of water in freshwater wetlands. Differential removal efficiencies of water column nitrogen (N) and phosphorus (P) may increase the severity of nutrient deficiency and possibly change the nutrient that limits primary production. A previous study demonstrated that periphyton in the Lake Waco Wetlands (LWW), near Waco, Texas, USA, are generally more P limited near the inflow and become increasingly N limited as distance from the inflow increases. Therefore, spatial heterogeneity in nutrient availability likely influences both the structure and function of periphyton assemblages within this system. In this ongoing study, we are evaluating the relationships between metaphyton primary production, nitrogenase activity, alkaline phosphatase activity, and CNP stoichiometry in areas of differing nutrient limitation within the LWW. As expected, primary production is generally greatest in areas where nitrogenase and alkaline phosphatase activities are minimal. However, expected increases in C:N ratios in areas of greatest nutrient deficiency have not been frequently observed. Decreased primary production and increased enzyme mediated nutrient uptake appear to balance metaphyton nutrient content in these areas.
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly