Populations of diurnal tree squirrels in the Portland area were located by mail surveys, personal interviews, and field inspections. Pine squirrels were found to reside in thickly wooded residential areas with dense understories and running water nearby. Western gray squirrels occupied habitats in relatively quiet residential neighborhoods, in areas well supplied with mast crops. Western fox squirrels were found to coexist with gray squirrels in their preferred habitat, and also to thrive in park settings with few mast trees and high activity and noise levels. In areas occupied by both fox and gray squirrels, dominant-subordinate relationships were noted. Each species tolerated the others.

Pathogens, such as Escherichia coli and fecal coliforms, are causing the majority of water quality impairments in U.S., making up ~87% of this grouping's violations. Predicting and characterizing source, transport processes, and microbial survival rates is extremely challenging, due to the dynamic nature of each of these components. This research built upon current analytical methods that are used as exploratory tools to predict pathogen indicator counts across regional scales. Using a series of non-parametric methodologies, with spatially explicit predictors, 6657 samples from non-estuarine lotic streams were analyzed to make generalized predictions of regional water quality. 532 frequently sampled sites in the Oregon Coast Range Ecoregion, were parsed down to 93 pathogen sampling sites in effect to control for spatial and temporal biases. This generalized model was able to provide credible results in assessing regional water quality, using spatial techniques, and applying them to infrequently or unmonitored catchments. This model's 56.5% explanation of variation, was comparable to other researchers' regional assessments. This research confirmed linkages to land uses related to anthropogenic activities such as animal operations and agriculture, and general riparian conditions.

The United States population continues to increase and diversify. The cultural composition within the United States embodies a multitude of people from a variety of belief systems, religious backgrounds, and ethnicities. Within current biomedical practice, many of these differences are often marginalized, leaving populations with unsatisfactory experiences in seeking health care. Cultural competency attempts to address those differences in health care delivery. Many health care institutions are striving to become more culturally competent yet there is not a common understanding of what cultural competency means. In addition, there are many obstacles that limit the implementation of cultural competency in health care delivery. This thesis examines the need for cultural competency in health care, addressing the lack of understanding between institutions regarding cultural competency and assessing its understanding at one particular institution. Recent research at Oregon Health & Science University in Portland, Oregon has provided new insight to the discussion of cultural competency and how uniquely it can be defined in a single institution. Qualitative interviews were conducted with medical students, physicians/physicians-in-training, administrators and nurses/CMA in order to uncover how cultural competency is defined as well as the issues that are involved when delivering culturally competent health care. By being aware of an institution's cultural composition and understanding of cultural competency can help that institution enact health programs and policies that have a better chance of representing and respecting the populations they serve. / Graduation date: 2003

Vineyard management strategies, including vineyard floor management and crop level management, can be used to influence vine vigor and fruit composition. Two studies were conducted to evaluate the impact of these practices on Pinot Noir in Oregon's Willamette Valley. Managing crop levels is common in cool climate vineyard production though it is a costly practice. With economic pressures, the premium winegrape industry is questioning whether they can reduce production costs and increase yields without compromising quality. A crop thinning trial was conducted in 2010 and 2011 to address these concerns and to better understand the role of vine balance on fruit composition. Crop levels were moderately (35% crop removed) or severely (65% crop removed) thinned at pre-bloom, fruit set, lag phase, or véraison and compared to full crop treatments. In both years, crop thinning reduced yields but had no effect on berry weight or cluster size. In 2010, poor fruit set reduced overall yields, and thinning treatments resulted in very few differences in vine growth, cluster architecture or fruit composition, including total soluble solids (TSS), pH, titratable acidity (TA), yeast assimilable nitrogen (YAN), anthocyanins, phenolics and tannins. In 2011, yields were much higher due to high fruit set and larger cluster size. No differences were found in vine growth (leaf areas or pruning weights) or fruit YAN, but thinned vines had higher TSS and pH and lower TA than full crop vines at harvest. Fruit thinned at lag phase and véraison had higher TSS and lower TA than fruit thinned pre-bloom. Intensity of thinning had a stronger influence on anthocyanin and tannin concentration than timing, while phenolics were not impacted by either factor. Ravaz index values (fruit yield/pruning weight) below 2.25 and leaf area to yield ratios of 2.25 to 3.25 m²/kg improved fruit composition in 2011 as did later season thinning, though data from the remaining years of this study will provide more insight into appropriate crop load metrics for cool climate Pinot Noir. A second study was implemented in 2011 to determine the impact of crop thinning in vines with different levels of vegetative vigor caused by three vineyard floor management techniques: permanent grass (Festuca rubra spp. rubra) cover (grass), alternating grass cover and tillage (grass & tilled), and tillage of every alleyway (tilled). Crop was thinned at the BB stage of berry development (EL stage 73) to one cluster per shoot (half crop) or not thinned (full crop); all cluster wings were removed at the time of thinning. Tillage treatments had been in place four years prior to the start of the study and competition for nitrogen in grass caused reduced early season vine growth, leaf chlorophyll and canopy size at both bloom and véraison while crop thinning increased canopy size at véraison. Yields were altered by tillage and crop thinning treatments, as grass had fewer clusters per shoot and berries per cluster, and crop thinning reduced yields to 64.7% of full crop across all tillage treatments. At harvest, grass had the lowest TA while TSS and pH were not affected by tillage. Crop thinning increased TSS but did not impact pH or TA. Anthocyanins were affected by both tillage and thinning and were found to be related to vine yield, YAN, leaf N, and leaf area index. Tannins were highest in grass but were not affected by crop thinning, and phenolics were not changed by either factor. Few interactions between tillage and crop thinning were found, but as variables such as yield per vine were impacted by both treatment factors, monitoring long term effects of crop / Graduation date: 2012

Debris flows, common disturbances in many mountainous areas, initially scour or bury stream habitats; however, debris flows deliver vast amounts of wood, boulders, and gravel that may ultimately form complex stream habitat to potentially support a diverse salmonid assemblage. The materials deposited by debris flows would otherwise be inaccessible to streams, and thus deposits may play an important role in creating and maintaining complex salmonid habitat over time. Despite the potential of deposits for increasing habitat complexity, most fish studies have focused on the destructive effects of debris flows and short-term recovery and re-colonization in scour zones. Debris-flows that occurred during the record-setting winter storms of 1996 in western Oregon, USA, provide an opportunity to study intermediate-term effects of debris-flow deposits on abundances and habitat for juvenile salmonids. In this setting, I surveyed salmonid abundance and habitat in three Oregon Coast Range streams that contained several debris-flow deposits from the 1996 storms. I explained fish abundance using hierarchical models, accounting for heterogeneous detection probabilities with repeated counts from multiple-pass snorkeling. The "best" hierarchical model of detection probability and abundance was selected (QAIC) from pool and snorkel-pass characteristics separately for juvenile coho salmon (Oncorhynchus kisutch), age 0+ trout, and age 1+ trout (Oncorhynchus spp.) in each stream. Adding distance to the nearest 1996 debris-flow deposit (DDF) produced a significant drop-in-deviance for four of nine "best" models, including at least one in each stream and for each species/age-class. In these four models, salmonid abundance decreased with increasing distance from deposit. As a potential explanation, several pool habitat characteristics were correlated (Spearman's rank) with DDF. Results varied across streams, but generally, percent of substrate as bedrock was lower and boulder density and percent substrate as gravel were higher closer to deposits. Although repeat counts are increasingly used in hierarchical modeling of heterogeneous detection probabilities and abundance for other wildlife species, studies of fish often rely on uncalibrated, single-pass snorkel counts. When exploring the value of repeat counts, I found that juvenile salmonid abundance decreased with increasing distance from debris-flow deposits in more multiple-pass hierarchical models that accounted for heterogeneous detection probabilities than for single-pass models that did not. Thus, modeling heterogeneous detection probabilities with repeated snorkel counts may be beneficial in other situations, addressing limitations of uncalibrated indices without relying on methods such as electrofishing, which may be difficult or impossible for remote study areas, longer surveys, or sensitive species. My findings suggest that debris-flow deposits may influence salmonid abundances after 15 years, and support management of debris flow-prone hillslopes and low-order channels to deliver elements of stream habitat complexity. / Graduation date: 2013

Three coastal Oregon dunal lakes, Mercer Lake, Munsel Lake, and Woahink Lake, were studied in an effort to determine if eutrophication has occurred since initial studies were conducted in 1938 and to determine each lake's current trophic status. Data collected in 1991 and 1992 for phytoplankton primary productivity; chlorophyll gi phytoplankton species, biovolumes, and densities; nutrients; optical characteristics; and dissolved oxygen were compared with historical data sets. Additional data for zooplankton, benthic invertebrates, and other relevant limnological data were used to more completely characterize each lake. Phytoplankton primary productivity measurements indicate that biological productivity has increased at each lake since 1969-1971. Chlorophyll ~ concentrations appear to have increased only at Mercer Lake. Other limnological data are insufficient to determine if and to what extent these lakes have eutrophicated. Based on data collected in 1991 and 1992, the current trophic state of each lake can be described as follows: Mercer Lake is mesotrophic to eutrophic but closer to mesotrophic, Munsel Lake is oligotrophic to mesotrophic but closer to mesotrophic, and Woahink Lake is oligotrophic to mesotrophic but closer to oligotrophic.

Calcium (Ca) is an essential macronutrient that is increasingly recognized as a biogeochemical factor that influences ecosystem structure and function. Progress in understanding the sustainability of ecosystem Ca supply has been hampered by a lack of information on the various forms and pools of Ca in forest ecosystems. In particular, few studies have investigated the role of Ca-oxalate (Ca-ox), a ubiquitous and sparingly soluble biomineral formed by plants and fungi, on Ca cycling. I investigated Ca-ox pools in two young Douglas-fir forests in the Oregon Coast Range, and found that Ca-ox comprised 4 to 18% of total ecosystem Ca in high- and low-Ca sites, respectively, with roughly even distribution in vegetation, detritus and mineral soil to 1 m depth. The proportion of ecosystem Ca existing as Ca-ox varied by ecosystem compartment but was highest in needle litterfall, foliage and branches. Calcium-ox could be a large amount of Ca in mineral soil; across nine sites comprising a local soil Ca gradient, we found as much as 20% of available Ca in 0 - 10 cm depth mineral soil occurs as Ca-ox. Ca-ox was the dominant form of Ca returned from plants to soil, but disappeared as rapidly as bulk Ca from decomposing litter, suggesting an important pathway for Ca recycling. In mineral soil, Ca-ox was a larger portion of total available Ca in the low-Ca site, which had lower Ca-ox concentrations overall, suggesting that Ca-ox has limited potential to buffer against Ca depletion in forests where Ca is in shortest supply. I investigated foliar chemistry as a method for diagnosis of nutrient deficiencies in high and low-Ca sites where Ca varied inversely with soil nitrogen (N), and which had received fertilization with urea (for nitrogen, N), lime, and calcium chloride three years prior. Foliar vector diagrams suggested N limitation at the low-N site and N sufficiency at the high-N site, but did not suggest Ca deficiency at either site after urea, lime and Ca-chloride fertilization. The high-Ca site displayed 20-60 times higher concentrations of foliar Ca-oxalate than the low-Ca site, although this was unaffected by fertilization. Soil nitrification responded to both N and lime fertilization at both sites, suggesting that fertilization with N may stimulate nitrification that could accelerate soil Ca loss. I also investigated how Ca-ox may influence cation tracers such as Ca and strontium (Sr) ratios (i.e., Ca/Sr) and Ca-isotopes (⁴⁴Ca/⁴⁰Ca), which are used to identify sources and pathways of Ca cycling in ecosystem studies. Laboratory synthesis of Ca-ox crystals exhibited preference for Ca over Sr, and for ⁴⁰Ca over ⁴⁴Ca. In the field, discrimination between Ca and Sr was detected in bulk plant tissues due to Ca-ox accumulation, suggesting that Ca-ox accumulation related to tree Ca supply status could influence interpretations of Ca/Sr as a tracer of Ca cycling. I also found that standard methods of soil exchangeable Ca extraction could dissolve Ca-ox crystals and potentially contribute an additional 52% to standard measurements of exchangeable-Ca pools in low-Ca sites, thus complicating long-standing interpretations of available soil Ca pools and dynamics in many studies. Results of this work show overall that Ca-ox is found in large quantities in plants, detritus, and mineral soil in forest ecosystems, and is a more dynamic component of ecosystem Ca cycling than previously recognized. / Graduation date: 2012

Using ����C cross polarization magic angle spinning nuclear magnetic resonance techniques on 5 species of dead trees from the northwest (western hemlock, Douglas fir, Sitka spruce, lodgepole pine and ponderosa pine) I tracked the lignin and cellulose content over a 22 to 36 year period in order to determine the effects of decay fungi, if any, that is attacking certain species of tree. I had samples from the wood of the roots, the bark on the roots and, in some cases, the resin core of the roots. The Department of Forest Science at Oregon State University has studied this problem by using wet chemical analysis, and direct visual observation. Mark Harmon and Hua Chen of the Department of Forest Science believe that white rot occurred most frequently in the lodgepole pine and ponderosa pine and brown rot was more frequent in the Douglas-fir and Sitka spruce. Western hemlock seemed to have both brown and white rots active. The Douglas fir bark sample showed definite decomposition consistent with white rot during the first 10 years. The ponderosa pine sap showed decomposition consistent with white rot in the 10 to 22 year period. Sitka Spruce showed some decomposition consistent with white rot in the bark from 7 to 33 years, and the western hemlock showed some decomposition consistent with white rot in the sap in the first 10 years. The decompositions consistent with brown rot were much easier to see in this study. Virtually all the sap and bark samples showed decomposition consistent with brown rot at some point. The Douglas fir was the only species, other than lodgepole pine, not to show any decomposition consistent with brown rot in the bark of the tree, only decomposition consistent with white rot. The Douglas fir did show a decay consistent with brown rot in the sap for the first ten years. Ponderosa pine showed evidence of decay that brown rot would cause for the first 10 years in the sap and the bark. The Sitka spruce species analysis showed brown rot type decay in the bark for the first 7 years and in the sap for the entire time studied of 33 years. The lodgepole pine was the only species to not show any brown rot type decay in the sap or bark for the entire 22 year period studied. The western hemlock was distinct by not showing any definitive brown rot type decay for the first 10 years, but showed massive decay consistent with brown rot in both sap and bark during the following 26 years studied. I used an 8 Tesla magnet and the MAS frequency was at 5 kHz. The recycle time was 1.5 seconds and the contact time was 1 ms. I generally took about 10,000 acquisitions per sample, which added up to about 4 hours total acquisition time per sample. Presence of these rots shows that certain species are more susceptible than others, and also shows that local environmental conditions can contribute to rot susceptibility. / Graduation date: 2003

Both red (Trifolium pratense L.) and white (Trifolium repens L.) clover seed yields can be highly variable and low in western Oregon. The objectives of this study were to: i) determine crop water requirements and supplemental irrigation timing, and ii) quantify the effects of soil and water status on inflorescence production, seed yield and seed yield components for red and white clover seed crops. In each species, five supplemental irrigation treatments were applied in 1990 and 1991 to first and second year seed crops grown on a Woodburn silt loam (fine-silty, mixed, mesic Aquultic Argixeroll) near Corvallis, OR. Non-irrigated controls were also maintained. In red clover, increased plant water stress reduced the duration of the season-long bud and flower production, stem length, potential floral capacity (PFC), and seed yield (SY). Root rot index (RRI) increased with increasing levels of plant water stress, indicating that supplemental water applications reduced second-year root rot severity. The reduction in SY from increasing plant water stress was primarily caused by a decrease in floral fertility, and less conclusively by reductions in inflorescence number per unit area. One irrigation to fill the soil active profile during peak flowering provided adequate water to maintain efficient seed production. In white clover, SY was maximum in 1990 when water application was delayed until 68% of the available soil-water was used by the crop which maintained an even flush of flowers and restricted vegetative growth. In 1991, all irrigation treatments yielded the same or less than the non-watered control. This was due to the excessive vegetative growth from stolons that had grown between the planted rows the previous and present crop year. In both years excessive amounts of irrigation water favored profuse vegetative growth and reduced SY. Inflorescence density was increased by constraining soil-water in 1990 and was the yield component that most affected SY both years. Crop water stress index (CWSI) was a useful indicator of plant stress status and can be used to schedule irrigations in red and white clovers grown for seed under typical climatic conditions of western Oregon. / Graduation date: 1993

Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been undertaken to preserve them. While considerable attention has been given to honey bees, relatively little is known about many native bee species. Of particular interest is the family Halictidae, which can comprise the majority of observed individuals in many habitats. These, often small, bees are difficult to identify, and, as a result, relatively little is known about their preferred floral hosts. Because bee species assemblages vary significantly from region to region, it is important to have an understanding of local populations and their floral hosts. It is also important to understand factors which affect the quantity and quality of floral resources, such as anthropogenic disturbance. The Pacific Northwest is a diverse landscape, with rich agricultural and wildland environments that require pollinators in order to continue to thrive. Two studies examine the interface between these two systems, the first explores how roadside disturbance, which is prevalent across the world, impacts native pollinators across habitat types, and the second explores the diet of common native species, and how that diet changes across habitat types. In these studies, it was found that roadside disturbance was associated with reduced native bee diversity and abundance in the seasonally wet Willamette Valley of Oregon, but not in the more xeric Central Oregon. Bee abundance was positively correlated with temperature. Bee diet was more diverse in areas of scarce floral resources. In both regions, exotic plants were important floral hosts, representing nearly half of observed floral visitations. This thesis presents results of species analysis, floral richness and density correlations, and comparisons of floral resources used by different bee species. Implications and recommendations for land management are discussed. / Graduation date: 2013