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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.
801

Private forests, public policy : oak conservation on family forests in Oregon's Willamette Valley /

Fischer, Alexandra Paige. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 227-250). Also available on the World Wide Web.
802

Patterns and processes of sediment transport following sediment-filled dam removal in gravel bed rivers

Stewart, Gregory B. 04 May 2006 (has links)
Graduation date: 2006 / Dam removal is increasingly viewed as a river restoration tool because dams affect so many aspects of river hydrology, geomorphology, and ecology; but removal also has impacts. When a dam is removed, sediment accumulated over a dam’s lifetime may be transported downstream; and the timing, fate and consequences of this sediment remain some of the greatest unknowns associated with dam removal. In this thesis, I develop a conceptual model for erosion and deposition following removal of sediment-filled dams in mountain streams, and use field studies to document actual change. The data show that reservoir erosion in mountain rivers is likely to occur by knickpoint migration, with 85% of stored sediment being released during a single storm event in two field studies, at shear stresses less than that required for mobilization of the median surface particle size. Coarse sediment is predicted to deposit close to the dam with channel aggradation decreasing exponentially with increasing distance downstream, although some channel features are shown to have a greater propensity for aggradation than others. Field studies show that turbidity associated with dam removal and reservoir erosion may decrease hyporheic exchange, but gravel deposition (e.g., 470 m3 of gravel from Dinner Creek Dam) has the potential to more than offset that decrease, and increased hyporheic exchange is shown to reduce diurnal temperature change. Macroinvertebrate density and taxa richness did not respond to dam removal itself, but rather with time-lagged reservoir erosion. Following reservoir erosion, macroinvertebrate density recovered quickly, although longterm taxa community composition appears to be altered. On the Sandy River, field measurements of shear stress and patterns of sediment deposition following cold lahars were used as an analog to predict the fate of fine sediment, which is likely to deposit far from the dam. Results show that the Sandy River has little capacity for fine sediment storage in pools above RK 6.4 (~ 42 kilometers below Marmot Dam) at discharges associated with reservoir sediment releases. Taken as a whole, this paper illustrates a complex suite of process that may accompany removal of sediment-filled dams in mountain rivers.
803

An evaluation of culverts on low volume forest roads in the Oregon Coast Range

Piehl, Bradley T. 25 July 1986 (has links)
WRRI 106 is placeholder for the research findings of Project No. G-928-03 funded by U.S. Dept. of the Interior, Geological Survey. Findings are available in Piehl, Bradley T. (1986) An evaluation of culverts on low volume forest roads in the Oregon Coast Range (Masters Thesis, Oregon State University. Forest Engineering) LD43301987.P52.
804

Patterns in understory vegetation communities across canopy gaps in young, Douglas-fir forests of western Oregon

Fahey, Robert T. 30 January 2006 (has links)
Graduation date: 2006 / Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps as an option in forest management regimes. This study examined understory vegetation communities across canopy gaps created as a part of the Density Management Study (DMS), which investigates the effectiveness of a thinning regime in promoting late-successional habitat development in young Douglas-fir forests of western Oregon. Patterns in understory vegetation community composition in and around 0.1 and 0.4ha gaps created as a part of the DMS treatment were investigated. The primary goal of this research was to investigate the potential role of canopy gap creation in fostering heterogeneity in understory vegetation communities, and to examine the extent of gap influence on the surrounding thinned forest matrix. Tree species distributions have been shown to partition across gaps in tropical forest systems through differential responses of species to gradients in resource availability, a pattern known as gap partitioning. In temperate forests, understory vegetation communities are much more diverse than the overstories, and display a greater array of habitat requirements. Therefore, understory communities may be more likely than overstories to exhibit gap partitioning in these forests. Patterns in understory community composition across gaps suggest that gap partitioning has occurred. The strength of this partitioning effect appears to differ between gap sizes, as smaller gaps showed a less powerful effect. Abundance of ruderal species was strongly related to gap partitioning in larger gaps, while smaller gaps were dominated by competitor species. Partitioning may be related to an interactive relationship between harvest-related ground disturbance and resource gradients. Therefore, considerations of gap partitioning processes should take into account intensity and spatial distribution of ground disturbance in relation to resource gradients. In addition, conditions necessary for the expression of gap partitioning in understory vegetation communities may be rare in natural gaps in this region. The influence of gaps on understory vegetation communities in the surrounding forest appears to be relatively small. This small influence extent may help explain the lack of a stand level response to gap formation in these stands. Larger gaps exhibit a slight influence on the understory plant community in the surrounding forest to the north of the gap. In small gaps, there seemed to be an influence of the surrounding forest on gap interiors, resulting in an area of influence smaller than the physical gap area. This relationship may indicate that the area of gap influence on understory vegetation may not scale linearly with physical gap size. Species diversity was higher in gap interiors than in surrounding thinned forests. However this effect was partially due to the presence of exotic species, which showed an affinity for gap interiors. Late successional associated species were negatively related to gap interiors, but only in the larger gap size. Gap creation appears to be promoting small scale species diversity in these stands, but creation of large gaps may also promote the establishment of exotic species and may have a negative effect on late successional associated species. However, any and all of these effects may be transient, as understory communities will be strongly affected by overstory re-establishment, and related changes in resource availability. In general, gap formation may influence small-scale stand heterogeneity as evidenced by understory plant communities, but this effect may rely strongly on the nature of gap formation and intensity of disturbance related to this formation.
805

The Analysis and Conservation of Two 18-pounder Carronades from the U.S. Navy Schooner Shark

Bajdek, Brennan P. 2012 May 1900 (has links)
In February of 2008, two 18-pounder carronades were discovered off the Oregon coast near Arch Cape in Clatsop County. In addition to the carronades, several associated artifacts were collected from the site, including lengths of chain, a heavy iron wedge and a mooring shackle. The carronades and associated artifacts were transported to Texas A&M University's Conservation Research Laboratory for long-term preservation and conservation. While the primary objective of this thesis is to detail the various methods used in conserving the Arch Cape artifact assemblage, the work also serves as an analysis of the carronades themselves. The design and caliber of the guns as well as historic accounts suggest the carronades are associated with Shark, a U.S. Navy schooner built at the Washington Navy Yard in 1821. During its 25-year career, Shark spent 18 years operating in the Atlantic Ocean suppressing piracy in the West Indies and the slave trade off the western coast of Africa. The schooner was also stationed in the Mediterranean Sea and the Pacific Ocean before a final survey in the Oregon Territory in 1846 resulted in its loss in the Columbia River. It was reported that part of Shark's wreckage with three attached carronades came ashore south of Hug Point. In January 1898, a winter storm revealed one of the carronades, which was recovered, along with the schooner's capstan, a cleat and a chock. The discovery of the pair of carronades in 2008 is strong evidence that these, along with the carronade recovered in 1898, are the three guns attributed to USS Shark's wreckage. This thesis will also analyze indentifying features on the carronades, such as maker's marks and serial numbers, and explore the origins of the guns, determining how they came to be on board the American schooner by referring to records such as the Woolwich proof books and armament lists. The harsh conditions of the coastal environment affect the assemblage in a number of ways. While much of the metal of the assemblage is stable and can be treated using electrolysis, the delicate organic materials must undergo specific treatments. Since these organic artifacts were treated primarily with silicone oil, the thesis will compare some of the final results of using this polymer passivation technology with different materials, such as wood, leather and cordage. Finally, in addition to detailing the conservation of the assemblage, this thesis describe the reverse engineering required to disassemble the carronades and gun carriages.
806

Keying forest stream protection to aquatic ecosystem values in multi-ownership watersheds

Pickard, Brian R. 15 March 2013 (has links)
Forested lands of western Oregon provide aquatic habitat for many fish and riparian dependent species, including a wide variety of salmon species. Current policies set riparian protections using fixed buffers on streams for federal and private lands based on stream type or size. These buffers can create a series of disjointed riparian protections, as federal lands require buffers that are much larger than private lands. In addition, the fixed buffer approach is neither flexible nor tailored to aquatic ecosystem values. This thesis presents a framework for comprehensively assessing stream networks using site specific watershed features and then suggests riparian conservation strategies that key stream and riparian protection to aquatic ecosystem values. Seven study watersheds were used in this analysis, totaling over 2.5 million acres of forested lands in western Oregon. Employing a set of geospatial tools, called NetMap, streams in each watershed were classified into higher and lower priorities using criteria of intrinsic potential, erosion/debris flow susceptibility, and thermal loading potential. Results demonstrated the inherent variability within and among watersheds based on the geomorphic and ecological processes determined important for selected salmon species. Within each watershed, both federal and non-federal lands had many miles of higher priority fish-bearing and non-fish bearing streams, suggesting the need for comprehensive, holistic watershed conservation strategies. Based on the partitioning of streams into higher and lower priorities, an alternative riparian conservation strategy was then modeled for federal lands that allocate protection on the basis of the ecological context of a stream segment’s potential and particular location while still meeting federal aquatic conservation goals and objectives. Possible increases to the land base for long-term timber production were then identified if this strategy were applied to federal Matrix lands. Results demonstrated that 8-30 percent of the current riparian buffers could be reallocated to the land base for long-term timber production. An additional 26-45 percent of current buffers could be managed simultaneously for both timber production and aquatic ecosystem goals. Results also provided a framework for targeting of conservation and restoration efforts towards higher priority streams within each watershed. As many of the most ecologically important streams were located on non-federal lands, riparian conservation policies focused on streams classified as higher priority on those lands may be needed to protect aquatic species and their environments. / Graduation date: 2013
807

Monitoring insecticide resistance of the western tentiform leafminer Phyllonorycter elmaella (Doganlar and Mutuura) (Lepidoptera: Gracillariidae) in northern Oregon

Shearer, Peter W. 12 December 1990 (has links)
Graduation date: 1991
808

Weed management for giant reed (Arindo donax) biomass production in Oregon

Attarian, Amir 06 March 2013 (has links)
Giant reed (Arundo donax L.) is a candidate to provide feedstock for the Portland General Electric power plant in Boardman, Oregon. Giant reed is a fast perennial grass, producing 23-27 metric tons ha⁻¹ of biomass and has the ability to adapt to diverse environments making it a good candidate for biomass production. This study tested postemergence and preemergence herbicides for controlling weeds in giant reed during the establishment year in which giant reed plants are more sensitive to weed competition. The greenhouse study demonstrated that among the tested herbicides, bromoxynil plus MCPA at 0.841 kg ai ha⁻¹, nicosulforun at 0.035 kg ha⁻¹, and dimethenamid-p at 0.735 kg ha⁻¹ did not injure giant reed. In a field study, preemergence application of dimethenamid-p at 0.735 kg ha⁻¹ followed by a postemergence application of 2,4-D amine at 0.560 kg ha⁻¹ and a postemergence application of bromoxynil plus MCPA at 0.841 kg ha⁻¹ did not injure giant reed. The presence of weeds in a field does not always mean that crop yield will be reduced and there are some periods during the growing season when weeds will not cause considerable yield loss. Therefore, predicting a critical period of weed control (CPWC) that includes the best time for weed control in giant reed could improve weed management in the field. The length of the CPWC could be different depending on the level of acceptable yield loss (AYL). Our results are reported for AYL of 5 and 10%. The CPWC started at 290 accumulated growing degree days (GDD) and ended at 820 for a 5% AYL, while for a 10% AYL, it started at 333 GDD and ended at 727 GDD. Based on the results, there are some herbicides which could be selected for further study for weed control in the giant reed and the estimated CPWC which could be used to inform weed management practices in giant reed production. / Graduation date: 2013
809

The effect of broadcast burning on the quality of winter forage for elk, westen Oregon

Friesen, Cheryl Ann 02 May 1991 (has links)
The Roosevelt elk (Cervus elephus roosevelti) is a National Forest management indicator species on the westside of the Cascade mountains, Western Oregon. A Habitat Effectiveness model is used by State and Federal agencies to evaluate elk habitat in the region. Concerns about the model's lack of differentiation between winter and summer ranges in the analyses and assumptions that burning will increase forage quality on winter range prompted this study. I investigated the effect of broadcast burning, plant association, and time since disturbance on the quality of trailing blackberry (Rubus ulna), red huckleberry (Vaccinium parviflorum), willow (Salix spp.), vine maple (Acer circinatum), salal (Gaultheria shallon), and red elderberry (Sambucus racemosa). Crude protein, neutral detergent fiber, acid detergent fiber, acid insoluble ash, lignin, astringency, condensed tannin, and hydrolyzable tannin contents were measured. No significant effects of burning, plant association, or age were observed for crude protein, hydrolyzable tannins, or neutral detergent fiber. Crude protein varied among taxa: trailing blackberry contained 9.65%, and the other taxa ranged from 5.21-7.24%. Neutral detergent fiber was highly variable: trailing blackberry contained 30.90%, and the other taxa ranged from 52.20%-65.06%. Acid detergent fiber content ranged from 44.88%-49.49% for all taxa except trailing blackberry (17.78%). Lignin varied among taxa: trailing blackberry had the lowest content (6.37%) and salal had the highest (30.25%). Lignin content in salal was greater on recently disturbed sites. Astringency ranged from 0.0015 mg protein precipitated per mg plant tissue in vine maple to 0.6737 in trailing blackberry. Salal and willow had intermediate astringencies: elderberry, huckleberry, and vine maple had the lowest. Hydrolyzable tannins were present in all species except red elderberry. Burning and plant association effected astringency and condensed tannin content in trailing blackberry and huckleberry. Samples from burned, very dry and resource-poor sites had higher astringencies than on similar unburned units and non-resource-limiting sites. Condensed tannin contents increased with unit age in salal, huckleberry, and trailing blackberry, possibly accumulating during peak years of re-establishment after disturbance. Vine maple and red huckleberry were the only taxa with positive digestible protein levels. Digestible protein content may be higher in winter forage on less severe sites. Elk forage enhancement in winter range should be evaluated on a site-specific basis. Burning did not promote a detectable increase in quality for these forage taxa, and it decreased the quality of species sensitive to site conditions. / Graduation date: 1991
810

A comparison of psychological characteristics of standout police officers and Oregon Police Academy trainees

Stevenson, Carl W. 09 July 1991 (has links)
Police officers are frequently viewed as being unable to perform the duties assigned to them by society. Criticism has focused on inappropriate reaction to social unrest and an inability to control crime. Improving the selection process of police officers has been proposed as an appropriate means of improving police officer performance. The problem is how to improve the selection process to select individuals who will perform at the highest level. This study attempted to determine if personality traits of standout police officers, as measured by psychological tests, differ significantly from personality traits of recruit police officers. Considerable research in Oregon has been done on personality traits of police officers. The research has dealt with testing police officer applicants and recruit police officers. This study compared the psychological profile of police academy trainees with the psychological profile of standout police officers. The standout police officers were identified in a study by John Koroloff. The standard t test was used for a comparison of personality traits based on test scores from the Law Enforcement Assessment and Development Report (LEADR), the Psychopathic Deviate scale (PD) and the MacAndrew Alcoholism scale (MA) of the Minnesota Multiphasic Personality Inventory (MMPI), and the Wonderlic Personnel Test. The LEADR consists of the 16 Personality Factors (16PF), the Clinical Analysis Questionnaire (CAQ), and second-order factors. A comparison was also made of the age difference between the two groups. The hypothesis that there is no statistically significant difference between the two groups was only partially supported. Statistically significant differences were found on the Intelligence, Low Energy Depression, Paranoia, Psychasthenia, Depression, and Psychoticism scales of the LEADR; on the Psychopathic Deviate and MacAndrew Alcoholism scales of the MMPI; and on the age difference. / Graduation date: 1992

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