Satellite Based evapotranspiration (ET) models have become a dominant means to estimate large-scale surface fluxes of water. Global and regional ET estimates are important parameters in many climate forecasts and hydrologic models. However, large scale partitioning of ET into soil evaporation, transpiration, and canopy interceptions remains largely unknown and modeled...
Mountainous headwater streams make up ~80 % of stream length globally and are strongly connected with catchment hillslopes and riparian areas, which can influence water quantity, quality, and availability for downstream uses. Accordingly, effective management of headwater streams and riparian zones to maintain desired ecosystem services downstream is critical, particularly...
This thesis focuses on the identification of ecohydrological processes in nested system of catchments in a tropical alpine (the wet Andean páramo) ecosystem. We accomplish this by conducting a water stable isotopic characterization of water sources, an evaluation of the mean transit time (MTT) of streams waters, and the investigation...
Copper and iron are essential micronutrients that are required by marine primary producers for a variety of metabolic processes. Over 99% of both copper and iron are bound within organic complexes in the marine environment, however the molecular identity of many of these complexes remains unknown. The speciation of these...
Pacific salmon (Oncorhynchus spp.) face numerous challenges associated with climate change. Most research has emphasized the potential effects of elevated summer water temperatures; however, climatic changes are also projected to significantly alter incubation and rearing habitats during the late autumn, winter, and spring months ("the incubation period"). Along the southern...
Two ecologically important lamprey species found in the endorheic Goose Lake Basin face conservation threats; however, relatively little is known about their habitat needs or spatial distribution. Lamprey and their habitat are often found to be patchy; to evaluate these relationships for the lamprey in this basin, I utilized a...
Mountain rivers are important aquatic ecosystems that regulate sediment and water delivery to higher order streams. While previous studies have debated the roles of hillslope and fluvial processes in driving change in channel morphology of mountain rivers, few have examined how these processes influence channel response over longer timescales. The...
Honey bees (Apis mellifera) are responsible for approximately $17 billion in crop production per year in the United States, and are arguably the most important pollinators in the nation. The future of crop pollination and production is threatened by widespread national honey bee colony losses, which have averaged approximately 30%...
Our understanding of nitrogen (N) and phosphorus (P) variability in forested stream systems with minimal disturbance is confounded by the complex interactions of hydrologic and biogeochemical controls. In this thesis, our studies evaluate the variability of stream water N and P in a forested, headwater system in the Oregon Coast...
The extent and severity of wildfires in forested regions are increasing throughout many regions on the planet, including western North America. High-severity wildfires directly affect soils and vegetation by altering soil hydraulic properties, reducing soil organic matter, exporting carbon and nitrogen, and killing trees and understory vegetation. These impacts can...