PLANT AND MICROBIAL COMMUNITY STRUCTURE, FUNCTION AND DYNAMICS IN A MISSISSIPPI DELTA CONSTRUCTED WETLAND

Authors: Weaver, Mark; Zablotowicz, Robert; Bryson, Charles

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/25/2003
Publication Date: 11/2/2003
Citation: Weaver, M.A., Zablotowicz, R.M., Bryson, C.T. 2003. Plant and microbial community structure, function and dynamics in a mississippi delta constructed wetland. [Abstract]. American Society of Agronomy.

Interpretive Summary:

Technical Abstract: A vegetated waterway in Sunflower County, Mississippi was converted in April 2002 to a three cell constructed wetland by erection of three dams and excavation to yield a capacity of about 1.3 million liters. An excavated area formed the thrid and final cell. This cell was populated by diverse assemblage of weeds, but following construction the vegetation in the excavated cell was almost exclusively Leptochloa panicoides . In the fall of 2002 the vegetation shifted to an almost pure stand of Alternanthera philoxeroides . The soil microbial community also changed in activity and composition. One year after wetland construction, soil dehydrogenase activity was significantly higher in the excavated cell than observed at any point prior to disturbance. Before wetland establishment fluorescein diacetate hydrolytic activity was greater in the center of the channel than on the banks; now the excavated cell has high hydrolytic activity across the entire cell. The microbial community was characterized by Fatty Acid Methyl Ester (FAME) community profiling prior to and following construction and compared to another nearby agricultural ditch and natural wetland. Before construction the site's FAME profile resembled that of the ditch. In the months since construction the FAME profile has shifted to more closely resemble the natural wetland.