This paper presents a framework for analyzing efficient spatial allocation of forest
management efforts - fuel treatment and harvest - under the risk of fire. The framework
integrates a fire behavior model and a spatially-explicit stochastic dynamic optimization
model. I investigate the effects of spatial interaction across plots during forest...
Two soils representative of the coast and three representing the Willamette Valley have been studied for their general chemical
characteristics. Exchange capacity and exchangeable cations were
determined by the ammonium acetate and the BaCl₂-triethanolamine
buffer methods. Exchange capacity was also obtained from conductimetric
titrations which were run on each soil...
Alteration of natural areas in attempts to support increasing human populations has been a crucial yet less publicized contributor to the fall of many of the world's greatest civilizations, since healthy ecosystems can help maintain stable societies and economies. Given this unhappy fact and the ancient relationship between people and...
Tidal wetland channels provide rearing habitat for juvenile Chinook salmon as they emigrate from freshwater habitat and prepare to enter the ocean. Widespread diking and drainage of estuarine marshes for agricultural and urban development may have contributed to a decline in salmon abundance in the Pacific Northwest, prompting efforts to...
The myxozoan parasite, Ceratomyxa shasta, is the most significant pathogen of juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Klamath River, CA, USA. This parasite requires two hosts - a freshwater polychaete (Manayunkia speciosa) and a salmonid - to complete its life cycle. The complex life cycle and large geographic area...
Despite evidence that juvenile Chinook salmon (Oncorhynchus tshawytscha) utilize North Pacific estuaries for growth and salinity acclimation, research in the Columbia River estuary has lead to opposing hypotheses about the estuary’s importance as a salmon rearing environment. Many contemporary tagging studies indicate that salmon residency within the estuary is short...
Understanding continental crust formation and modification is a fundamental and longstanding geologic problem. Influx of mantle-derived basaltic magma and partial melting of the crust are two ways to drive crustal differentiation. This process results in a low density upper crust and denser, more refractory lower crust, creating significant and vastly...
This study provides an empirical test of the Bockstael-McConnell
(1980) household production function (HPF) framework for evaluating wildlife recreation. This is perhaps the first study in which
both taste and technology parameters have been estimated with a
theoretical model specification. The results suggest that for
steelhead sport fishing in Oregon,...
Representative sites of the Dayton, Woodburn, Jory, Quillayute, Astoria, Willamette, Walla Walla, Deschutes, Laki and Owyhee soil series were investigated for seasonal changes in exchangeable potassium in air dry samples. No consistent seasonal variations were found which could be attributed to wetting and drying in the field. Cropping reduced the...
The numerous different types of nanomaterials and paucity of reliable in vivo information on toxicity has resulted in enduring uncertainties associated with health and safety risks, thereby slowing progress in nanotherapeutic assessment and development. This dissertation explores how the embryonic zebrafish model can be applied to prioritize commonly used nanomaterial...
In this thesis we construct compatible discretizations of Maxwell's equations. We use the term compatible to describe numerical methods for Maxwell's equations which obey many properties of vector Calculus in a discrete setting. Compatible discretizations preserve the exterior Calculus ensuring that the divergence of the curl and the curl of...
Per- and polyfluoroalkyl substances (PFAS) are a group of anthropogenic compounds gaining notoriety as contaminants of emerging concern. With the frequent detection of PFAS in the environment, drinking water, and consumer products, awareness and concern from the public regarding PFAS is increasing. The two most notorious PFAS are perfluorooctanoate (PFOA)...
Sea otters fulfill a keystone role in several Northeastern Pacific nearshore ecosystems. However, their influence has been absent in Oregon coastal waters since their extirpation in the 19th and early 20th century. Interest has been growing for a translocation attempt to reintroduce sea otters to Oregon from one or more...
Arctic warming is exposing thawing permafrost to repeated freeze-thaw, a disruptive process that can alter soil biogeochemistry and physical structure. To investigate the impact of permafrost exposure to freeze-thaw, soil response was tested across three scales: 2.5 cm³ aggregates, a forested hillslope, and two sites at contrasting latitudes. XCT imaging...