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Articles 1 - 4 of 4
Full-Text Articles in Ecology and Evolutionary Biology
Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro
Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro
Graduate Student Theses, Dissertations, & Professional Papers
Human activities have doubled the rate of nitrogen inputs onto the landscape resulting in elevated nitrogen concentrations in our streams. Anthropogenically applied nitrogen is largely transported to stream networks via groundwater movement. Groundwater discharge occurs in distinct points along a stream but whose influences can often persist far beyond that area due to insufficient biogeochemical removal of imported nitrogen potentially causing alterations in community structure and precipitating large algae blooms. To understand the factors governing nitrogen abundance in a historical polluted stream, I used a mass-balance approach to quantify groundwater-surface water interaction and the magnitude of groundwater nitrogen input and …
Food Web Effects Of Lake Trout (Salvelinus Namaycush) Invasion In Northwestern Montana, Charles Wainright
Food Web Effects Of Lake Trout (Salvelinus Namaycush) Invasion In Northwestern Montana, Charles Wainright
Graduate Student Theses, Dissertations, & Professional Papers
Around the turn of the 20th century, lake trout (Salvelinus namaycush) were widely introduced in several lakes and reservoirs outside their native range in western North America. Since then, lake trout have become problematic in many lakes where they were introduced, causing significant declines in popular sport fishes and native species, most notably federally protected bull trout (Salvelinus confluentus). Despite evidence that invasive fish can cause cascading trophic effects in aquatic communities, the impacts of lake trout introduction / invasion on aquatic food webs remain poorly understood. Moreover, native fish restoration programs tend to focus on suppression …
Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones
Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones
Graduate Student Theses, Dissertations, & Professional Papers
This dissertation describes the estimation, error quantification, and incorporation of land surface information from microwave satellite remote sensing for modeling global ecosystem land-atmosphere net CO2 exchange. Retrieval algorithms were developed for estimating soil moisture, surface water, surface temperature, and vegetation phenology from microwave imagery timeseries. Soil moisture retrievals were merged with model-based soil moisture estimates and incorporated into a light-use efficiency model for vegetation productivity coupled to a soil decomposition model. Results, including state and uncertainty estimates, were evaluated with a global eddy covariance flux tower network and other independent global model- and remote-sensing based products.
Population Differentiation And Habitat Selection Of A Montane Red Fox Population In The Greater Yellowstone Ecosystem, Patrick Cross
Population Differentiation And Habitat Selection Of A Montane Red Fox Population In The Greater Yellowstone Ecosystem, Patrick Cross
Graduate Student Theses, Dissertations, & Professional Papers
Montane red fox (Vulpes vulpes) populations across the western United States are genetically and morphologically distinct from foxes at lower elevations. These montane populations also share a preference for subalpine forest habitats. One hypothesis is that they stem from boreal forest-associated ancestors that expanded during the Pleistocene when boreal forests extended farther south than they do today. Forest habitat selection may therefore aid the persistence of native populations surrounded by non-native conspecifics. Alternatively, this behavior may be an avoidance mechanism in response to competition with larger coyotes (Canis latrans), or a product of the fox's natural adaptability. The red fox …