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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

LiDAR Predictive Modeling of Kalapuya Mound Sites in the Calapooia Watershed, Oregon

Cody, Tia Rachelle 22 March 2019 (has links)
Archaeologists grapple with the problematic nature of archaeological discovery. Certain types of sites are difficult to see even in the best environmental conditions (e.g., low-density lithic scatters) and performing traditional archaeological survey is challenging in some environments, such as the dense temperate rain forests of the Pacific Northwest. Archaeologists need another method of survey to assess large areas and overcome environmental and archaeological barriers to site discovery in regions like the Pacific Northwest. LiDAR (light detection and ranging) technology, a method for digitally clearing away swaths of vegetation and surveying the landscape, is one possible solution to some of these archaeological problems. The Calapooia Watershed in the southern Willamette Valley in Oregon is an ideal area to focus LiDAR's unique archaeological capabilities, as the region is heavily wooded and known to contain hundreds of low-lying earthwork features or mounds. Modern Indigenous Communities, such as the Confederated Tribes of Grand Ronde, consider the Willamette Valley mound sites highly sensitive locations, as ethnographic accounts and limited archaeological work indicate that some are burial sites. However, these mounds have received little archaeological study. Land ownership (94 percent privately owned), dense vegetation that obscures mounds, and the sheer expanse of the landscape (234,000 acres) have impeded professional archaeological research. The focus of this thesis is the development and the testing of a LiDAR and remote sensing predictive model to see if this type of model can detect where potential mound sites are located in the Calapooia Watershed, Oregon. The author created a LiDAR and remote sensing predictive model using ArcMap 10.5.1, LiDAR, and publicly available aerial imagery; manipulating data using standard hydrological tools in ArcMap. The resulting model was successful in locating extant previously identified mound sites. The author then conducted field work and determined that the model was also successful in identifying seven new, previously unrecorded mound sites in the watershed. The author also identified several possible patterns in mound location and characteristics through exploratory model analysis and fieldwork; this exploratory analysis highlights areas for future mound research. This project has clearly established a method and a model appropriate for archaeological mound prospection in the Willamette Valley. This project also shows the efficacy of LiDAR predictive models and feature extraction methods for archaeological work, which can be modified for use in other regions of the Pacific Northwest and beyond. Furthermore, by identifying these mounds I have laid the groundwork for future studies that may continue to shed light on why and how people created these mounds, which will add valuable information to a poorly understood site type and cultural practice.
42

Assessment of impacts of Canada geese on wheat production

Louhaichi, Mounir 22 January 1999 (has links)
Numbers of wild Canada geese (Branta canadensis) have increased dramatically during the past 30 years in the lower Columbia and Willamette Valley systems. The damage they cause by grazing and trampling plants can be substantial. The objectives of this research were to: 1) Develop methods that provide reliable estimates of goose impact on wheat yield and quality, and 2) Develop methods to separate goose damage from other factors that lower yield such as poor soil or waterlogging. To document grazing impacts, color aerial photography was combined with Global Positioning System (GPS) and precision farming technology. Field-scale color aerial photographs (1:14,000 scale) were acquired four times during each growing season: in January, March, April, and just prior to harvest in July. Each flight was coupled with ground truth data collection to verify exact cause of spectral signature variation or variations in wheat cover. Such data included wheat height, number of goose droppings, and a relative rating of goose grazing intensity. At each sampling point a platform photograph and a GPS location were taken. Wheat yield impact varied considerably as field size, shape and proximity to road varied. Yield maps revealed that, goose grazing had reduced grain yield by 25% or more in heavily grazed areas. At harvest time during the first year, wheat grain in the heavily grazed areas had higher moisture content due to delayed maturity. Therefore those areas were harvested two weeks later. Heavily grazed areas also had more weeds than ungrazed portions of the field. Late-season (April) grazing was more damaging to wheat yield than was earlier season grazing, but early season grazing did have an impact on yield. Intensely hazed fields had lower levels of damage than did fields or portions of fields that were not as vigorously guarded. Our results illustrate very practical ways to combine image analysis capability, spectral observations, global positioning systems, precision farming and ground truth data collection to map and quantify field condition or crop damage from depredation, standing water, or other adversities. Image analysis of geopositioned color platform photographs can be used to stratify winter wheat fields into impact units according to grazing intensity. Ground-truth data, when collected in conjunction with a GPS, provided the information needed to locate and establish the spectral properties of impacted areas. Once the spectral properties of a representative area were identified, information could be extrapolated to other areas with the same characteristics. In addition, this method could be used in conjunction with aerial photography to verify areas of grazing. The combination of two or more of these tools would provide farm managers and agricultural consultants with a cost-effective method to identify problem areas associated with vegetation stress due to heavy grazing by geese or other factors. / Graduation date: 1999
43

Restoring oak habitats in the Southern Willamette Valley, Oregon: A multi-objective tradeoffs analysis for landowners and managers

Ulrich, Nathan D., 1977- 12 1900 (has links)
xvii, 160 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Restoring oak habitats is an emerging conservation priority in Oregon's Willamette Valley. Both private and public landowners face multiple challenges to conservation and restoration of oak habitats, including a lack of knowledge about the potential tradeoffs and constraints for achieving multiple priorities on a given site. This study simulated 25 alternative oak habitat restoration scenarios to develop estimates of outcomes related to six different restoration priorities: costs, income potential, habitat value, scenic quality, fire hazard reduction potential, and time requirements. Model results indicated that initial land conditions strongly influence a landowner's ability to optimize among these different priorities. To assist landowners with decision-making, model estimates were organized into a digital decision matrix that communicates advantages and tradeoffs associated with each alternative scenario. In doing so, it aims to help landowners choose restoration goals that better meet their broader needs and objectives. / Committee in Charge: Dr. Bart Johnson, Chair; Dr. Robert Ribe
44

Oregon outdoor garments : outdoor garments worn in the Willamette Valley and Eastern Oregon regions between 1880 to 1920

Mower, Jennifer M. 01 May 2006 (has links)
The purpose of this study was to describe women's outdoor garments worn in Oregon from 1880 to 1920 to determine whether there were garment differences between the Willamette Valley and Eastern Oregon. The question addressed was: can garment differences be explained by the different Oregon climates, geographic locations, and availability of goods throughout Oregon during this time? Harper's Bazar and The Ladies' Home Journal were used to identify popular outdoor garment styles by date. A data collection instrument was developed using other instruments and secondary sources as guides. The form allowed collection of information about garment construction, fiber and fabric, and style. Various historical societies and museums throughout Oregon were visited and extant garments from various historical clothing collections were analyzed, photographed, and drawn to scale. When available, information about the original owner and use of the outdoor garments were collected. The information was coded, and it was determined that the sample was too small to statistically determine if there were regional outdoor garment differences. Therefore, frequencies were analyzed and compared. There were some regional garment differences, but they do not appear to be the result of climate and geographic differences. Differences were most likely due to the availability of ready-to-wear outdoor garments and materials. Some outdoor garments were used only for special occasions, while others were worn by multiple family members over a long period of time. / Graduation date: 2006
45

Distribution of Oligonychus (Oligonychus) ununguis (Jacobi) (Acari: Tetranychidae) and predator mite species (Acair: Phytoseiidae) on field-grown Douglas-fir (Pseudotsuga menziesii [Mirb] Franco) Christmas trees

Calkin, James D. 20 February 1991 (has links)
The shake and wash technique (samples placed in a jar with alcohol added and shaken to remove the mites) was effective in removing 100% of the predator mites, and adult spruce spider mites from Douglas-fir foliage and 98% of the spruce spider mite nymphs. Eighty-eight percent of the spruce spider mite eggs was removed. This technique was considered efficient for removal of spruce spider mite and its predators from Douglas-fir foliage. Sodium hypochlorite (0.84%) added to the alcohol did not increase the number of spruce spider mites or phytoseiid mites removed from the foliage. The intracanopy distribution of spruce spider mite and its predator mites was studied on Douglas-fir Christmas trees in the Willamette Valley, Oregon. When overwintering spruce spider mite egg densities populations were low (<5 eggs/19 cm of stem), significantly more eggs were found on the current season's growth. No significant differences were found between top and bottom halves of the tree or between compass directions. Differences between current and previous season's growth were not found when egg densities were high (>40 eggs/19 cm of stem), but significant differences were found between levels for current season's growth with more eggs found in the upper portion of the canopy. Quadri-directional differences did not exist with either low or high mite populations. Sampling tip or basal stem-halves with low overwintering egg populations did not bias population estimates. Heavy spring rainfall appeared to reduce mite populations as has been reported elsewhere by washing them off the tree and causing increased mortality. Spruce spider mite disperse to the current season's growth shortly after budbreak. Population density rapidly increased in late May and then abruptly declined in mid-July. / Graduation date: 1991
46

Introduced plant species, herbivores and pathogens, and the host-enemy relationships that accompany invasions

Blaisdell, Gretchen Kai, 1974- 03 1900 (has links)
xvi, 109 p. : ill. / Invasions by introduced plant species cost billions of dollars each year in the United States and threaten native habitat. The primary goal of my dissertation research was to examine the role that natural enemies (pathogens and herbivores) play in these invasions in both unmanaged and restored plant communities. In two related studies in seasonal wetland prairies in the Willamette Valley, Oregon, USA, I surveyed natural enemy attack on common native and introduced plant species in a restoration experiment designed to test the effects of site preparation techniques on plant community composition. Restoration treatments had little influence on enemy attack rates. Attack rates depended on idiosyncratic differences in the relationships between host species and plant community characteristics, suggesting that existing theories concerning these relationships have limited predictive power. Another field experiment tested the potential for enemy spillover from introduced to native species and dilution of natural enemy attack on introduced species by native species. I examined natural enemy attack on three native and three perennial grasses that commonly co-occur in the Willamette Valley. The native species are commonly used in restoration. The introduced species are common throughout North America and potentially harbor enemies that could affect both crops and natural communities. There was no compelling evidence of enemy spillover from the introduced to the native species, but dilution of enemies on the introduced species by the native species was evident in year 2 and even stronger in year 3 for two of the three introduced species. Using the same three introduced species from the spillover/dilution study, I tested the enemy release hypothesis, which proposes that introduced species lose natural enemies upon introduction and are thus "released" from population control. I surveyed populations of the three grass species across a wide geographic area in their native and naturalized ranges in Europe and the United States, respectively. I also compared my results to those of a previously published literature survey. My field survey supported release from herbivores but not from fungal pathogens. In contrast, the literature survey found evidence of release from fungal pathogens. This dissertation includes unpublished co-authored material. / Committee in charge: Brendan Bohannan, Chairperson; Bitty Roy, Co-Advisor; Scott Bridgham, Co-Advisor; Eric Seabloom, Member; Robert Mauro, Outside Member
47

Burnout: a multi-dimensional study of alienation among social service workers in the Willamette Valley

Carignan, Sally, Deihl, John, Harris, Judy, Jones, Jay, Rothman, Bonnie, Ullmann, Sabrina, Weinberg-Gordon, Beth, Weter, Phyllis, Whitty, Patricia, Wilson, Loretta 01 January 1981 (has links)
In a profession such as social work, where one is responsible for dealing with the ills of society and meeting the needs of other individuals, such emotional detachment and estrangement from others is antithetical to the purpose of the field and eminently destructive to those seeking and needing assistance. With the current push for accountability, factors such as burnout or alienation from one's work become of crucial importance. In addition, burnout leads to a high rate of absenteeism and job turnover (Minihan, 1980). This too decreases cost effectiveness and the quality of service, matters of extreme concern in a field designed to serve the needs of individuals in society and to do so on limited funds and resources. Thus, alienation is of paramount importance to the field of social services and can no longer be ignored or relegated to a back seat in terms of study and research. Current literature in the field of social work deals only with the subjective expression of alienation; it has omitted linking the psychological with the social-structural aspects of alienation: indeed, with linking burnout to alienation itself. This study proposes to begin to fill this gap. What conditions in the structure of the work place and/or society cause or are correlated with the expression of alienation? It is this question which we endeavor to pursue.
48

Breeding success and nest site characteristics of the western bluebird on Parrett Mountain

Sims, Marcia Diane 01 January 1983 (has links)
The lack of suitable nest sites may be a limiting factor for Western Bluebird populations inhabiting the upper Willamette Valley. Nest box trails have been established on the hills surrounding the Portland metropolitan area. Since their placement, approximately 25% of the boxes available have been used by Western Bluebirds as nest cavities. This study was undertaken to identify factors which might determine the selection of a nest box by Western Bluebirds and the subsequent nest success or failure. The breeding biology of Western Bluebirds using the nest box trail located on Parrett Mountain, Oregon in 1979 was investigated. Breeding season, mean clutch size, average incubation and nestling periods, and level of nest success were determined. Nest box dimensions, placement, and surrounding habitat features were quantified. Potentially important nest site characteristics were examined and tested for association with Western Bluebird nest box use and reproductive success. Western Bluebird nest box selection was random with regard to all of the characteristics studied except Solar Index and Nest Box Density. No correlation was seen between nest box characteristics and bluebird nest success.
49

Natural and Anthropogenic Influences on the Holocene Fire and Vegetation History of the Willamette Valley, Northwest Oregon and Southwest Washington

Walsh, Megan Kathleen, 1976- 12 1900 (has links)
xvii, 382 p. : ill. (some col.), maps. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The debate concerning the role of natural versus anthropogenic burning in shaping the prehistoric vegetation patterns of the Willamette Valley of Oregon and Washington remains highly contentious. To address this, pollen and high-resolution charcoal records obtained from lake sediments were analyzed to reconstruct the Holocene fire and vegetation history, in order to assess the relative influence of climate variability and anthropogenic activity on those histories. Two sites provided information on the last 11,000 years. At one site at the northern margin of the Willamette Valley, shifts in fire activity and vegetation compared closely with millennial- and centennial-time scale variations in climate, and there was no evidence that anthropogenic burning affected the natural fire-climate linkages prior to Euro-American arrival. In contrast, the fire and vegetation history at a site in the central Willamette Valley showed relatively little vegetation change in response to both millennial- and centennial-scale climate variability, but fire activity varied widely in both frequency and severity. A comparison of this paleoecological reconstruction with archaeological evidence suggests that anthropogenic burning near the site may have influenced middle- to late-Holocene fire regimes. The fire history of the last 1200 years was compared at five sites along a north-south transect through the Willamette Valley. Forested upland sites showed stronger fire-climate linkages and little human influence, whereas lowland sites located in former prairie and savanna showed temporal patterns in fire activity that suggest a significant human impact. A decline in fire activity at several sites in the last 600 years was attributed to the effects of a cooling climate as well as the decline of Native American populations. The impacts of Euro-American settlement on the records include dramatic shifts in vegetation assemblages and large fire events associated with land clearance. The results of this research contribute to our understanding of long-term vegetation dynamics and the role of fire, both natural- and human-ignited, in shaping ecosystems, as well as provide an historical context for evaluating recent shifts in plant communities in the Willamette Valley. / Advisers: Cathy Whitlock, Patrick J. Bartlein
50

White-breasted nuthatch density and nesting ecology in oak woodlands of the Willamette Valley, Oregon

Viste-Sparkman, Karen 30 January 2006 (has links)
Graduation date: 2006 / Habitat loss causes a reduction in available resources for wildlife, alters the configuration of remaining habitat, and may isolate wildlife populations. White-breasted nuthatches (Sitta carolinensis) are experiencing long-term population declines in the Willamette Valley of Oregon, where they are historically associated with oak woodlands. As secondary cavity-nesters, white-breasted nuthatches may be limited by the availability of existing cavities for nesting and roosting. Oak vegetation in the Willamette Valley has changed since European-American settlement times from vast areas of open oak savanna to isolated closed-canopy stands separated by agricultural fields. We examined nuthatch density, nest cavity selection, and nest success in relation to oak woodland structure and landscape context. We conducted point transect surveys in 3 strata: woodland interiors, large woodland edges, and small woodlands. We located and monitored nuthatch nests and sampled vegetation at nest locations and matching random locations around each nest. Woodland structure and edge density were measured at a 178-m radius (home range) scale, and landscape context was measured using vegetation cover within a 1-km radius around point transects and nests. We used program DISTANCE to fit detection functions and calculate nuthatch densities. We used conditional logistic regression to compare nest locations with random locations, and analyzed nest success with Mayfield logistic regression. White-breasted nuthatch density was significantly higher in small woodlands than in edges of large woodlands, which had higher nuthatch density than woodland interiors. Density of nuthatches increased with a combination of oak cover within a 1-km radius of the point, edge density within a 178-m radius, and number of oak trees >50 cm diameter at breast height (dbh) within a 100-m radius. Nest cavities were situated in oak trees containing more cavities than random oak trees that had cavities, and oak trees used as nest trees had a larger dbh than oak trees within random plots. Local woodland structure at nest locations was characterized by larger trees, measured by greater mean dbh, canopy cover, and basal area of oaks than random locations within the home range. Nest success in natural cavities was 71% and was not predicted by attributes of nest cavities, nest trees, local woodland structure at nests, woodland structure at the home range scale, or landscape context. These results suggest that the most suitable habitat for white-breasted nuthatches in the Willamette Valley includes oak woodlands in close proximity to one another with a high proportion of edge and mature oak trees. Managers should preserve trees containing cavities and large oak trees whenever possible. Thinning of small oaks and removal of conifers in oak woodlands to create more open, savanna-like conditions may also promote the development of larger oaks with more spreading branches, providing more opportunities for cavities to form and more foraging surface area for nuthatches.

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