This dissertation integrates a process-based hydrological investigation with an
ongoing paired-catchment study to better understand how forest harvest impacts
catchment function at multiple scales. We do this by addressing fundamental questions
related to the stocks, flows and transit times of water. Isotope tracers are used within a
top-down catchment intercomparison...
The mouth of the Columbia River (MCR) is an intersection of more than a river and ocean, but also multiple economically valuable activities including dredging to maintain a deep draft shipping channel and an active Dungeness crab (Metacarcinus magister) fishery. More than three million cubic meters of sediment are annually...
Significant inputs of hydrocarbons are continually released into the environment from anthropogenic and natural sources. Some of the most toxic hydrocarbon compounds are polycyclic aromatic hydrocarbons. Polycyclic aromatic hydrocarbons are known for their ability to absorb ultraviolet light and enhance toxicity. Generally, PAHs exert their toxicity via narcosis but UV-absorbing...
Surface water quality is a growing concern in the Willamette River Basin and elsewhere. The region's growing population is dependent on the availability of clean water for drinking water, irrigation, wastewater dilution, and wildlife habitat. Watershed management to produce economic goods and environmental services requires an understanding of basic hydrologic...
Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them is critical for ecosystem management of marine resources. The Gulf of Alaska (GOA) is a large marine ecosystem that includes...
Wetland restoration mitigates effects of agricultural development on water quality, flooding, and habitat loss. Multi-objective optimization for wetland locations and sizes has not included objective functions for water quality, hydrology, and habitat in unison, limiting analysis of trade-offs among these ecosystem services. This study establishes two methods to improve the...
Bird and bat mortalities caused by interactions with wind turbines is a critical concern that requires addressing for conservation purposes. Deploying a low cost sensor array will be instrumental during site permitting, conducting impact assessments of existing wind farms, and assessing efficacy of wildlife mortality mitigation or wildlife deterrent technologies....
Hatcheries are often perceived as a source of pathogen amplification, potentially increasing disease risk to free-ranging populations; at the same time, free-ranging fishes may introduce pathogens into hatcheries through untreated water sources. Many pathogens exist naturally within the environment (with the exception of introduced pathogens) and the presence of a...
Lodgepole pine (Pinus contorta) forests are widely distributed throughout western North America. However, the lodgepole pine forests of central Oregon are ecologically unique to the region, with a mixed severity fire regime, low cone serotiny, and their occasional presence as a climax species. Most of the research conducted regarding the...
The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, snow covered area, and earlier spring snowmelt are documented trends that are projected to continue into the future. With an...