HR: 1330h
AN: NB33I-02    [Abstracts]
TI: Macroinvertebrates Associated With Emergent Macrophyte Decomposition in a Constructed Wetland.
AU: * Nelson, M
EM: msnelson@do.usbr.gov
AF: U.S. Bureau of Reclamation, P.O. Box 25007, D-8220, Denver, CO 80225-0007 United States
AU: Thullen, J
EM: joan_thullen@usgs.gov
AF: U.S. Geological Survey, P.O. Box 25007, D-8220, Denver, CO 80225-0007 United States
AU: Sartoris, J
EM: jsartoris@do.usbr.gov
AF: U.S. Geological Survey, P.O. Box 25007, D-8220, Denver, CO 80225-0007 United States
AB: This study took place at the San Jacinto constructed wetland in California. Wetland water is supplied to irrigators in this cooperative venture between Reclamation and the Eastern Municipal Water District. One of the problems at this highly productive site is that plant litter accumulates to where it needs to be managed by taking the wetland off-line, thus impacting O&M costs and water delivery schedules for extended periods. Information on decomposition rates and conditions needed to encourage invertebrate decomposers was required to improve wetland reliability and decrease biomass management costs. Standing dead culms of bulrush (Schoenoplectus) were collected and air-dried to constant weight. Twenty-gram culm packs were placed in the wetland and then collected at two month intervals. Comparisons between fine-mesh and coarse-mesh packs demonstrated that exclusion of aquatic invertebrates decreased processing. This was also demonstrated in laboratory studies. It also appeared that culm pack decomposition rate varied with the macroinvertebrate community, and that community distribution was influenced by water quality. Study results confirm the importance of vegetation management through water management and wetland design. Maintaining healthy, sustainable ecosystems will help to encourage natural decomposition processes and maintain better water quality.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly