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Full-Text Articles in Physical Sciences and Mathematics
Brine Shrimp Ecology In The Great Salt Lake, Utah, Wayne A. Wurtsbaugh
Brine Shrimp Ecology In The Great Salt Lake, Utah, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
Hypersaline lakes are noted for their simple communities which facilitate understanding ecological interactions (Williams et al. 1990; Wurtsbaugh 1992; Jellison and Melack 1988). Nevertheless, we still cannot easily predict how environmental changes will effect the population dynamics in these lakes, at least in part because even these simple ecosystems may be more complex than we .realize. Many hypersaline lakes are dominated by the brine shrimp Artemia spp. The production of brine shrimp is often very high because the terminal, saline lakes accumulate nutrients that make them rich, and because the short food chains in them (nutrients-->phytoplankton-->brine shrimp) minim …
The Trophic Gradient In Lake Powell, Wayne A. Wurtsbaugh, G. Steinhart
The Trophic Gradient In Lake Powell, Wayne A. Wurtsbaugh, G. Steinhart
Watershed Sciences Faculty Publications
From April 21 st to April 25th, 1995 students from Utah State University's FW 462 class sampled the trophic gradient in Lake Powell between Bullfrog (Mile 99) and Hite Marinas (Mile 144). We sampled at 3-12 stations along the gradient, depending on the parameter measured. The purpose of the trip was three-fold. First, the primary objective of the class was to provide field and laboratory experiences in aquatic ecology for the students. Secondly, we wished to provide data on the trophic environment that the endangered razorback sucker larvae from the Colorado River would encounter when the entered the reservoir. Thirdly, …
Acidic Deposition, Ecosystem Processes, And Nitrogen Saturation In A High Elevation Southern Appalachian Watershed, C. S. Nodvin, H. Van Miegroet, S. E. Lindberg, N. S. Nicholas, D. W. Johnson
Acidic Deposition, Ecosystem Processes, And Nitrogen Saturation In A High Elevation Southern Appalachian Watershed, C. S. Nodvin, H. Van Miegroet, S. E. Lindberg, N. S. Nicholas, D. W. Johnson
Watershed Sciences Faculty Publications
High-elevation red spruce-Fraser fir forests in the Southern Appalachian mountains: 1) receive among the highest rates of atmospheric deposition measured in North America, 2) contain old-growth forests, 3) have shown declines in forest health, 4) have sustained high insect-caused fir mortality, and 5) contain poorly buffered soils and stream systems. High rates of nitrogen and sulphur deposition (sim1900 and sim2200 Eq·ha–1·yr–1, respectively) are dominated by dry and cloud deposition processes. Large leaching fluxes of nitrate-nitrogen (100–1400 Eq·ha–1·yr–1) occur within the soil profile. We have expanded the study to the watershed scale with monitoring of: precipitation, throughfall, stream hydrology, and stream …
Inorganic Nitrogen Determined By Laboratory And Field Extractions Of Two Forest Soils, H. Van Miegroet
Inorganic Nitrogen Determined By Laboratory And Field Extractions Of Two Forest Soils, H. Van Miegroet
Watershed Sciences Faculty Publications
To assess the effect of a delay in soil processing on inorganic N levels in N-rich soils, field and laboratory extractions were compared at two forested sites with high N mineralization and nitrification potential. At eight sampling dates in 1989 and 1990, five mineral soil cores per site were taken between 0- and 10-cm depth and transported on ice to the laboratory for KCl extraction and NH4-N and NO3-N analysis. At three sampling dates in 1990, soil extractions were performed in the field immediately following sampling, and inorganic N concentrations were compared between extractions. Nitrate-N increased four- to sevenfold (net …
Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh
Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
Historically, thousands of Snake River Sockeye salmon returned to the Sawtooth Valley to spawn. Evermann (1896) reported that the Sawtooth Valley Lakes were teeming with red fish. Bjornn (1968) estimated that 4,360 sockeye returned to Redfish Lake in 1955. These numbers no longer exist. In the 1980's, less than 50 . Snake River sockeye salmon survived to spawn (Bowler 1990). Since 1990, only 14 sockeye have returned. Because of recent declines, the Shoshone-Bannock Tribes (SBT) petitioned the National - Marine Fisheries Service (NMFS) to list · Snake River sockeye as endangered. As a result, Snake River sockeye were listed and …