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Full-Text Articles in Physical Sciences and Mathematics
Risk Mapping For Northern Kenya And Southern Ethiopia, D. Layne Coppock
Risk Mapping For Northern Kenya And Southern Ethiopia, D. Layne Coppock
Environment and Society Faculty Publications
We used results from 120 group interviews collected in 1998 to quantify how inhabitants across northern Kenya and southern Ethiopia perceive and rank various risks to their livelihoods. We also mapped risk patterns using Global Positioning System (GPS) coordinates. Respondents recognized 15 sources of risk overall, with the most common being reliable access to food and water. Other risks were not mentioned by a majority of respondents and reflected diversity in local situations. Country of residence, wealth class, gender, and predominant means of food production (pastoralism, agro-pastoralism, and farming) influenced risk ranking. For example, wealthy males were most concerned about …
Effects Of Epilimnetic Versus Metalimnetic Fertilization On The Phytoplankton And Periphyton Of A Mountain Lake With A Deep Chlorophyll Maxima, Wayne A. Wurtsbaugh, H. P. Gross, Phaedra E. Budy, Chris Luecke
Effects Of Epilimnetic Versus Metalimnetic Fertilization On The Phytoplankton And Periphyton Of A Mountain Lake With A Deep Chlorophyll Maxima, Wayne A. Wurtsbaugh, H. P. Gross, Phaedra E. Budy, Chris Luecke
Watershed Sciences Faculty Publications
Nutrients can load directly to either the epilimnion or metalimnion of lakes via either differential inflow depths of tributaries or intentional fertilization of discrete strata. We evaluated the differential effects of epilimnetic versus metalimnetic nutrient loading using 17-m-deep mesocosms that extended into the deep chlorophyll layer of oligotrophic Pettit Lake in the Sawtooth Mountains of Idaho. Addition of nitrogen plus phosphorus stimulated primary production nearly identically (2.4- to 4-fold on different dates) in both treatments, with the production peaks occurring in the strata where nutrients were added. The metalimnetic fertilization, however, resulted in equal or greater stimulation of chlorophyll a …
Salmonine Consumption And Competition For Endemic Prey Fishes In Bear Lake, Utah-Idaho, J. R. Ruzycki, Wayne A. Wurtsbaugh, Chris Luecke
Salmonine Consumption And Competition For Endemic Prey Fishes In Bear Lake, Utah-Idaho, J. R. Ruzycki, Wayne A. Wurtsbaugh, Chris Luecke
Watershed Sciences Faculty Publications
Two principal sport fish—the indigenous Bonneville cutthroat trout Oncorhynchus clarki utah and the introduced lake trout Salvelinus namaycush—are the dominant piscivores in Bear Lake, a 282-km^2 oligotrophic system. These piscivores rely predominantly on four endemic prey fish species that make up a major portion of the unique Bear Lake fish assemblage. We estimated the annual biomass of pelagic and benthic prey fish by using hydroacoustic and trawling techniques. We also estimated the lakewide abundance of piscivores with a multiple mark–recapture survey and used a bioenergetics model to compare the population-level consumption of prey fish with prey fish production. Prey fish …