Inventory and Mapping of Aquatic Plants at Lake Roosevelt National Recreation Area
Sytsma M and Miller R. 2008. Inventory and Mapping of Aquatic Plants at Lake Roosevelt National Recreation Area. Natural Resource Technical Report. NPS/UCBN/NRTR—2008/076. National Park Service. Fort Collins, Colorado
Lake Roosevelt is a large reservoir in northern Washington formed by the Grand Coulee Dam, which inundates portions of the Columbia River, the Spokane River, and other rivers and streams. In recent years, Lake Roosevelt National Recreation Area (LARO) staff noted an increase in the density of submersed aquatic plants, including the nonnative, invasive Myriophyllum spicatum, in the lake. Excessive submersed plant growth interferes with recreational use of the lake and impairs water quality. LARO staff established test plots of nonchemical treatments (rototilling, forced heat, solarization, benthic barriers, and no-treatment control) at five sites during the drawdown period in the spring of 2007. The treatments were then sampled in August and percent biomass by species was estimated. Eleven submersed aquatic plant species and one macroalgae species were documented. The nonchemical treatments did not consistently impact biomass or species composition (at one site, this was due to treatment disturbance by swimmers). Water column chemistry and sediment differences may explain some differences in biomass between sites. More replication of treatment plots would have aided in interpretation of the results.
- Type
- Published Report
- Authors
- Sytsma, Mark; Miller, Rich
- Date of Issue
- 2008-01
- Publisher
- National Park Service
- Units
- LARO , NRSS , UCBN
- Keywords
- aquatic plant, Biomass, Columbia River, cultivation, Drawdown, Dunn’s multiple comparison test, Impact, Inventory, Lake Roosevelt, Lake Roosevelt National Recreation Area, macrophyte, Mapping, nonchemical treatment, Presence (Biodiversity), Recreation, Reservoir, solarization, Spokane River, Taxa Links To References, Vegetation Inventory