Open Access. Powered by Scholars. Published by Universities.®

Systems Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Systems Biology

Wildfires Are Burning Less Frequently And More Severely Than Historically In The Western Us: A Novel Approach To Calculating Fire-Regime Departures, Jeffrey Ryan Chandler Jan 2024

Wildfires Are Burning Less Frequently And More Severely Than Historically In The Western Us: A Novel Approach To Calculating Fire-Regime Departures, Jeffrey Ryan Chandler

Graduate Student Theses, Dissertations, & Professional Papers

Changing climate, vegetation, and fire exclusion are altering and homogenizing fire-regime attributes compared to historic conditions. Fire-regime changes are commonly quantified using departure metrics, which are often based on measures of central tendency (i.e. changes in the mean). These metrics can mischaracterize complex changes to the distributional characteristics of fire-regime attributes. Here we develop a fire-regime departure metric that quantifies nonparametric distributional changes to fire-regime attributes over time. We use this metric to compare fire frequency and severity between historical (~1600-1880) and contemporary (1880- 2021) time periods in western US forests. Our analysis revealed that 89% of Western US forests …


Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro Jan 2021

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 Jan 2020

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 …


Characterizing The Requirements For The Matricellular Protein, Dccn, In Nervous System Function, Elizabeth L. Catudio Garrett Jan 2020

Characterizing The Requirements For The Matricellular Protein, Dccn, In Nervous System Function, Elizabeth L. Catudio Garrett

Graduate Student Theses, Dissertations, & Professional Papers

The brain is organized as a complex network of specialized neurons that communicate via a combination of electrical and chemical signals. Our brains function to generate movement, control organ function, or direct complex behaviors; all of which requires the ability to regulate the flow of communication between circuits and networks. Work in this thesis addresses two areas of neuron communication: first, how does the release of more than one neurotransmitter from a single neuron impact behavior, and second, are matricellular proteins (MCPs) key contributors to synaptic transmission and neuron function? The conserved CCN family of MCPs have a …


Spatiotemporal Dynamics Of Nitrogen And Carbon Biogeochemistry In A Wetland-Stream Sequence, Patrick E. Hurley Jan 2019

Spatiotemporal Dynamics Of Nitrogen And Carbon Biogeochemistry In A Wetland-Stream Sequence, Patrick E. Hurley

Graduate Student Theses, Dissertations, & Professional Papers

Studies of aquatic ecosystems often segregate streams from the influential ponds, lakes, and wetland zones that act as important transitions between terrestrial and fluvial systems. Across the aquatic landscape, these zones interact to form linked ecosystems that function as discrete nutrient processing domains, shifting biogeochemical signals due to spatial and temporal variability in hydrologic and biologic controls. Using a mass-balance approach, we profiled nutrient dynamics along a 23-km wetland-stream sequence over three seasons. Hydrologic, morphologic, and biologic conditions, as well as landscape attributes, were quantified to determine potential controls on biogeochemical cycling in a tributary of the Upper Clark Fork …


Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones Jan 2016

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.


The Sensitivity Of Soil Respiration To Soil Temperature, Moisture, And Carbon Supply At The Global Scale, Andrew Hursh Jan 2015

The Sensitivity Of Soil Respiration To Soil Temperature, Moisture, And Carbon Supply At The Global Scale, Andrew Hursh

Graduate Student Theses, Dissertations, & Professional Papers

Soil respiration is one of the most important terms in the global carbon budget, yet we know very little about how important environmental factors control this process at the global scale. Soils contain more carbon than terrestrial biomass and the atmosphere combined and contribute ten times more carbon dioxide to the atmosphere each year than the burning of fossil fuels. This study provides new insight on the factors driving soil respiration at the global scale by assimilating satellite observations of soil moisture, temperature, and net primary productivity with the Global Soil Respiration Database (SRDB).While temperature, moisture, carbon supply and other …


Population Differentiation And Habitat Selection Of A Montane Red Fox Population In The Greater Yellowstone Ecosystem, Patrick Cross Jan 2015

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 …