Changing demographics in Oregon, accompanied by a rising Latino population, serve to dispel myths that we live in homogeneous, monolithic communities. Migration studies indicate migration is reshaping communities, contributing to ethnic diversity thus challenging our notion of identity and culture. Through the medium of oral histories and ethnography, this study describes the composition of the Latino Community in Yamhill County, identifying migration, immigration, and sociohistorical processes that formed the community. This work explores ideas of ethnicity, identity, and community building and how it has shaped Latino context and experience in Yamhill County. The voices of the participants express how they interpret their context and ways in which they are shaping it to be their own. This study also investigates the ways in which the participants interpret the American dream, essentially, what success means to them and what tensions inhibit full participation in the community. Like the pioneers on the Oregon Trail, they too came in search of freedom, of opportunity, of adventure. They tolerated discrimination and isolation along their journey--yet similar to the Oregon Trail pioneers, they pooled resources, they endured hardship, they persevered--to achieve their dreams. They counter the stereotypes of minorities expecting handouts or entitlements; rather, they have pursued their dreams and hopes in the face of obstacles those from the culture of power rarely even recognize. Their pioneering spirit adds a new dimension to the stories told about the Oregon country. Their stories tell us more about our country and more about ourselves. / Graduation date: 1999

Graduation date: 1998

Graduation date: 1999

I monitored demography, movement, and reproductive behavior of gray-tailed voles, Microtus canicaudus, in experimental habitat patches with and without corridors. I tested the hypotheses that reproductive rate, juvenile recruitment, and population size and growth rate would be affected negatively by immigrants that were introduced to resident groups (+ male and + female treatments). I hypothesized that "strangers" would commit infanticide thus decreasing juvenile recruitment. Second, I determined if movement corridors facilitated dispersal among habitat patches, thus potentially increasing infanticide, but decreasing reproductive inhibition of opposite-sex relatives by allowing them to separate (corridor treatment). Experiments were conducted in 12 0.2 ha enclosures planted with alfalfa that was fragmented into four patches (each 156 m��) separated by 12.5 m of bare ground. Introduction of unfamiliar conspecifics did not adversely affect reproductive rate, juvenile recruitment, population size, density, or growth rate. Corridors facilitated dispersal movements with males moving more than did females; however, corridors did not result in an even distribution of animals in the four patches. Unconnected habitat patches resulted in female- rather than the typical male-biased dispersal and females dispersed at lower body mass than in controls. Males that did not disperse from their natal patch exhibited a slight delay in sexual maturation. I conclude that movement is deterred in patchy environments, enhanced with corridors, and differentially affects males and females. Behavioral factors that affect an individual's dispersal or reproductive pattern should be considered in landscape planning. / Graduation date: 1997

The shallow aquifer in Northeast Malheur County, Oregon is polluted with Nitrates at concentrations exceeding federal drinking water standards. Efforts to solve the groundwater problems in this area have focused on developing farm management practices that will increase groundwater quality while maintaining agricultural production. Furrow irrigation is the dominant practice for irrigating row crops in this region. One potential way to improve water quality is to increase furrow irrigation performance on a regional scale. In this study a surface irrigation model, SRFR, was linked to a geographic information system (GIS) for the purpose of evaluating alternate furrow irrigation strategies in Malheur County, Oregon. SRFR is a physically based model that simulates water flow and distribution in irrigated furrows. The model accepts the management parameters that influence the outcome of an irrigation and in return provides measures of water application efficiency, amount of deep percolation, amount of surface run-off, and other performance indicators. The GIS, constructed using ARC/INFO software, contains the spatial data required to run SRFR on individual fields in the region. The data for the GIS were acquired using many different sources and techniques in order to meet the input resolution required by the irrigation model. The primary goal of this research was to develop a tool for evaluating irrigation practices on a regional scale, accounting for the diversity of physical circumstances and management practices that occur within a complex of several hundred farms. The particular application of this tool was for control of nitrate pollution of groundwater in the vicinity of Ontario, Oregon. The integrated system was used to estimate a base condition irrigation that is representative of current irrigation practices. The system was then used to assess irrigation performance using three alternative practices: 1) separate management of wheel and nonwheel compacted furrows; 2) use of an automated control system to vary application set times; and 3) cutback irrigation. Although this represents only a limited assessment of the alternatives that might be considered for the study area, preliminary results suggest that under certain field conditions irrigation efficiency can potentially improve more then 20% over the base condition using alternate strategies. The system demonstrated tremendous potential for identifying trends and variability in system performance in the region. / Graduation date: 1997

Despite the increase in information on the causes of foodborne disease, outbreaks continue to be a major preventable public health problem. Current food service establishment inspection programs, however, are not designed to assess the potential of risk for foodborne disease and do not focus prevention efforts where food service problems are more severe. The purpose of this study was, therefore, to first, compare mean inspection scores, mean number of critical violations, and mean risk index values for high risk, moderate risk and low risk food service establishments in Marion County, Oregon. Second, the study determined if menu risk assessment can be used to identify facilities that are considered to be "high risk" facilities. The data included most recent routine inspection results that had been previously collected by local sanitarians and data collected from a Menu Risk Assessment Survey which was developed by the Virginia Department of Health. The Menu Risk Assessment Survey was administered using a stratified random design, to 400 food service managers/owners between October 1993 and December 1993 The results showed that high risk establishments had lower mean inspection scores, higher mean number of critical violations, and a smaller mean risk index value than moderate or low risk establishments. The differences were attributed to lack of manager food safety education, menu items served, and operational practices observed in the establishment. The results also showed that there were statistically significant differences (p<.05) in the mean inspection score and the mean number of critical violations of "high risk" establishments and "low risk" establishments when responses to the Menu Risk Assessment Survey were compared. For example: 1) Establishments whose managers do not have food handler's training demonstrate more critical violations than establishments with trained managers, 2) Critical violations and lower inspection scores were more likely to occur in establishments that prepared and served potentially hazardous foods, 3) Food service establishments that handle extensive amounts of potentially hazardous food and serve larger populations were more likely to have lower inspection scores and increased numbers of critical violations. Based on the results found in this research, local health departments may find the Menu Risk Assessment Survey to be a useful tool in determining high, moderate, and low risk food service establishments to focus prevention efforts where the problems are more severe and are of greater public health risk. / Graduation date: 1997

Wind energy is a promising alternative energy source due to its environmental, economic, and social benefits and, as such, has garnered public support and government incentives for its development and implementation. With the growing number of wind parks in Oregon, a life cycle assessment (LCA) study for a representative new wind park is needed to investigate the potential impacts on the environment. One of the major drawbacks of wind energy generation is its variability due to the stochastic nature of wind. To make wind energy a more reliable source, wind energy generation should be supplemented with controllable energy generation or storage. Thus, the aim of this research is to improve the understanding of the effects of supplemental energy systems on the environmental impacts of wind energy systems. First, the environmental impact of a single wind turbine is examined from raw material extraction to the end of life stage. Research needs are identified to support the assessment of the environmental impacts of wind energy and supplemental energy systems from a life cycle perspective. Next, supplemental electricity generation systems investigated are biomass, hydro, and natural gas electricity generation, and zinc-bromine battery storage. Finally, the results for each system are compared to coal energy generation. It appears that the wind park has lower environmental impact than coal energy generation when paired with any of the complimentary systems investigated. Overall, hydropower appears to be the best option to supplement wind power from an environmental perspective for a potential wind park site in northern Oregon. / Graduation date: 2013

Responses of juvenile steelhead trout to changes in stream habitat resulting from an instream habitat rehabilitation project in Meadow Creek, Oregon were measured from 1991 through 1992 and compared to pre-treatment data from 1987 through 1990. Sixty nine pool-forming, and 59 channel-stabilizing log structures were constructed by the U.S. Forest Service in a 3.7 km reach in 1990. A 20-year flood caused extensive modifications to the instream structures in May 1991. Pool habitat and large wood volume increased in the treatment and the two reference reaches but pool development was greater in the treatment reach compared to the two reference reaches. Summer rearing densities of juvenile steelhead were similar for the treatment and the two reference reaches at the reach scale. Summer rearing densities were lower in the post-treatment period compared to the pre-treatment period for the treatment and two reference reaches. Mean density of juvenile steelhead was higher in complex pools compared to non-complex pools throughout the study area. Mean density of juvenile steelhead was higher in pools associated with large wood from washed-out structures compared to pools associated with intact structures in the treatment reach. Changes in smolt production from the treatment reach following the rehabilitation project could not be determined due to trapping difficulties. Only three percent of the smolts emigrating from the basin overwintered in the treatment reach in 1992. Four life history patterns of juvenile steelhead were identified. Only one of the four life history patterns rears in the Meadow Creek basin until smolting. From these findings I conclude that the instream habitat rehabilitation project did not increase the abundance of juvenile steelhead or smolt production during the first two years after treatment. An extended drought and a 20-year flood may have been the dominant factors controlling abundance of juvenile steelhead over the study period. The Meadow Creek rehabilitation project may have limited success at increasing smolt production because it influences only one of four life history patterns of juvenile steelhead during the entire freshwater rearing phase. / Graduation date: 1997

Graduation date: 1996

Twelve stream segments in the Silvies River drainage system were classified in the fall of 1993 and again in 1994, using a morphological classification of natural rivers (Rosgen 1994). Bankfull flow of stream channels is the key feature of this system. Measurement of bankfull is used in the calculation of entrenchment ratio and width/depth ratio. Analysis of the differences of the averages between years in bankfull measurements showed that despite being consistently repeated at the same locations along the channel, the measurements were found to be different (p=0.000163 for entrenchment ratios and p = 0.0208 for width/depth ratios). Bankfull was found to be a non-repeatable field measure, therefore, a poor benchmark for a classification scheme. Historical information collected for the study area indicated a history of domestic livestock use that dates back as far as the mid-nineteenth century. Although grazed by livestock for several years, settlement of the Bear and Silvies Valleys occurred mostly around the turn of the twentieth century after the stockgrower's homestead acts were passed. Ownership today is dominated by large (relative to the homestead days) ranches. / Graduation date: 1996