HR: 1330h
AN: NB33C-02    [Abstracts]
TI: Seasonal Phosphorus and Nitrogen Trends During Restoration of the Wood River Wetland, Klamath Falls, Oregon
AU: * Duff, J
EM: jhduff@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Carpenter, K
EM: kdcar@usgs.gov
AF: U.S. Geological Survey, 10615 SE Cherry Blossum Drive, Portland, OR 97216 United States
AU: Watkins, W
EM: Wedge_Watkins@blm.gov
AF: Bureau of Land Management, 2795 Anderson Ave, Klamath Falls, OR 97603 United States
AU: Avanzino, R
EM: avanzino@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AU: Triska, F
EM: fjtriska@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 United States
AB: From 1985-1994, the 3200 acre Wood River Wetland (WRW) was managed as irrigated pasture for beef cattle production. In 1996, a project to restore the historical wetland was initiated to provide long-term improvement in water quality and quantity entering Agency/Klamath Lake. Presently, the WRW is managed for seasonal wetland habitat (1600 acres) and more permanent marsh/open water habit (1400 acres). Between May and August 2003, TP increased from 4 to 19 mg P/L. TP was significantly higher in the wetland than in source waters, including artesian groundwater and surface streams. TP increased at the same rate as specific conductance, suggesting that the increase resulted from water evaporation rather than biological or geochemical processes. Approximately 75-95 percent of the TP was soluble inorganic P. TKN, like TP, increased from 7 to 19 mg N/L and was significantly higher in the wetland than in any potential source. TKN, unlike TP, consisted mainly of an organic form of N, with 10 percent or less composed of ammonium and nitrate. Since SRP dominated the TP pool, and concentrations were exceedingly high, there was little biological impact on the P cycle. The low concentrations of bioavailable N indicated a significant biological impact on the inorganic N cycle.
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly