Index Catalog // ScholarsArchive@OSU

Examination of the role host-selective toxins play in fungal-plant interactions

Creator:: Andrie, Rachael M.
Abstract:: Pyrenophora tritici-repentis, causal agent of tan spot of wheat, produces multiple host-selective toxins (HSTs), including Ptr ToxA, encoded for by ToxA, Ptr ToxB, encoded for by ToxB, and Ptr ToxC. Variable distribution of these three HSTs among different isolates of P. tritici-repentis, both singularly and in all possible combinations, defines...
Resource Type:: Dissertation

Relationships of exotic species and wildfire to the threatened plant Silene spaldingii

Creator:: Menke, Carolyn A.
Abstract:: In the canyon grasslands of Garden Creek Ranch Preserve in Idaho, where the threatened plant Silene spaldingii occurs and invasion by the exotic species Centaurea solstitialis and Bromus tectorum is proceeding rapidly, I examined environmental and community patterns of site invasion, and evaluated the apparent influence of invasion on Silene...
Resource Type:: Masters Thesis

Epidemiology of grape powdery mildew, Uncinula necator, in the Willamette Valley

Creator:: Hall, Tyrone W.
Abstract:: An important disease of Vitis vinifera production in Oregon and all other commercial growing regions is powdery mildew of grape, caused by the obligate fungal pathogen Uncinula necator (Schwein.) Burril. Grape production can be characterized as a long-term investment in the establishment and maintenance of the vineyard. Establishment times have...
Resource Type:: Masters Thesis

Effects of Preinoculation with VAM fungi isolated from different sites on plant tolerance to salinity in soils amended with sodium chloride

Creator:: Cantrell, Isabella Cardona
Abstract:: The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be...
Resource Type:: Masters Thesis

Factors limiting the distribution of the sensitive lichen Usnea longissima in the Oregon Coast Range : habitat or dispersal?

Creator:: Keon, Dylan B.
Abstract:: The sensitive lichen Usnea longissima Ach., formerly a fairly common circumboreal species, has been extirpated from much of its range (e.g., Eastern Europe). Although the U.S. Pacific Northwest (PNW) remains a relative stronghold for the species, U longissima faces increasing pressure in the region from habitat loss, air pollution, and...
Resource Type:: Masters Thesis

Assessment of potato tuber blight caused by Phytophthora infestans

Creator:: Glass, Jenny Rebecca
Abstract:: Late blight, caused by Phytophthora infestans, is a devastating problem to potato production in many parts of the world. While the foliar phases of this disease are well characterized, tuber infection, leading to quality losses and disease perpetuation, is less well understood. Experiments were conducted during 1998 and 1999 in...
Resource Type:: Masters Thesis

Shrub epiphyte communities in relation to stand management in forests of western Oregon

Creator:: Rosso, Abbey L.
Abstract:: This dissertation describes the epiphyte communities on tall shrubs in forests of western Oregon, with a focus on potential effects of management practices on these communities. Shrubs and other hardwoods have recently gained recognition as hotspots of diversity for epiphytes in young conifer forests of the region. Yet little is...
Resource Type:: Dissertation

The effects of nitrogen manipulations and hydrology on the establishment and competitive abilities of wetland prairie plant species (western Oregon)

Creator:: Davis, Kimberly J.
Abstract:: Many studies suggest that weedy plant species are most successful when soil nitrogen in abundant. Consequently, I used soil nitrogen manipulations to determine if altering nitrogen would affect the establishment of both weedy and native plant species in a western Oregon wetland prairie. In two studies, we added carbon amendments...
Resource Type:: Dissertation

Sensitivity of wheat genotypes to a toxic fraction produced by Cephalosporium gramineum and correlation with disease susceptibility

Creator:: Rahman, Mahfuzur
Abstract:: Cephalosporium stripe, caused by the soil-borne ascomycete Cephalosporium gramineum, is becoming an increasingly important disease of winter wheat (Triticum aestivum) in several areas of the world, especially where stubble mulch is practiced to maintain soil moisture and prevent erosion. As cultural control of the disease is infeasible and no fungicides...
Resource Type:: Masters Thesis

The association of epiphytic macrolichens and bryophytes with riparian stand types along a valley continuum, Oregon Coast Range

Creator:: Ruchty, Andrea M.
Abstract:: I surveyed epiphytic macrolichens and bryophytes in six stands in each of seven riparian stand types in the Oregon Coast Range. This study (Chapter 2) describes the association of epiphytes with stand types and the corresponding potential of forest canopy conversions to affect epiphyte communities. Species composition, diversity, and representation...
Resource Type:: Masters Thesis

Port-Orford-cedar and Phytophthora lateralis : grafting and heritability of resistance in the host, and variation in the pathogen

Creator:: McWilliams, Michael G.
Abstract:: Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to a small area of Oregon and California. A root disease caused by Phytophthora lateralis causes widespread mortality of Port-Orford-cedar. This dissertation examines three important elements of the Port-Orford-cedar P. lateralis pathosystem related to breeding for disease resistance: use of resistant rootstocks...
Resource Type:: Dissertation

Analysis and prediction of patterns in lichen communities over the western Oregon landscape

Creator:: Peterson, Eric B.
Abstract:: The diverse lichen flora of the Pacific Northwest is being impacted by population growth and by forest management practices. Accumulating information about our lichen flora will improve our conservation strategies. This dissertation first collects information to improve our understanding of how lichen communities vary among forests of differing structure, and...
Resource Type:: Dissertation

Distribution and prediction of Swiss needle cast of Douglas-fir in coastal Oregon

Creator:: Rosso, Pablo H.
Abstract:: This study was directed to improve our understanding of the ecology of Swiss needle cast (SNC) of Douglas-fir, a disease that produces extensive damage to forests and plantation in the coastal region of Oregon and Washington. A disease prediction model for the coastal area of Oregon was built by establishing...
Resource Type:: Dissertation

Hop cone tip blight : a new disease in the Pacific Northwest

Creator:: Bienapfl, John C.
Abstract:: A necrosis at the tip of cones was observed on hop (Humulus lupulus), cultivar "Nugget", grown in Oregon in the early 1990's. Fusarium sambucinum and F. avenaceum were recovered from symptomatic cones in 1998 and preliminary inoculation experiments suggested both Fusarium species could cause hop cone necrosis. Studies were carried...
Resource Type:: Masters Thesis

Multiple functions of a proteinase in closterovirus life cycle

Creator:: Peng, Chih-Wen
Abstract:: More than half of the recognized genera of positive strand RNA viruses employ polyprotein processing as one of the strategies for their genome expression. Normally, this processing is mediated by virus-encoded proteinases that belong to the trypsin-like or papain-like family. In particular, papain-like, leader proteinases were found in diverse families...
Resource Type:: Dissertation

The imprint of coarse woody debris on soil biological and chemical properties in the western Oregon Cascades

Creator:: Spears, Julie D. H.
Abstract:: The abundance and spatial heterogeneity of coarse woody debris (CWD) on the forest floor is a prominent feature of Pacific Northwest (PNW) forest ecosystems. The effect of CWD on soil solution chemistry, nutrient cycling and availability, soil physical structure and formation of soil organic matter, however, remains unknown. Therefore, studies...
Resource Type:: Dissertation

Effects of host resistance on Mycosphaerella graminicola populations

Creator:: Cowger, Christina
Abstract:: Mycosphaerella graminicola (anamorph Septoria tritici) causes Septoria tritici blotch, a globally important disease of winter wheat. Resistance and pathogenicity generally vary quantitatively. The pathogen reproduces both sexually and asexually, and the pathogen population is highly genetically variable. Several unresolved questions about the epidemiology of this pathosystem are addressed by this...
Resource Type:: Dissertation

Phylogenetics, population genetics, molecular epidemiology, and pathogenicity of the Douglas-fir Swiss needle cast pathogen Phaeocryptopus gaeumannii

Creator:: Winton, Loretta M.
Abstract:: A hierarchical series of studies, based mainly on molecular data, was conducted to elucidate the life history of the Douglas-fir Swiss needle cast pathogen Phaeocryptopus gaeumannii at macro- and micro-evolutionary scales. This information was then utilized to design and evaluate molecular diagnostic tools for use in studies on the epidemiology...
Resource Type:: Dissertation

Litter decay processes and soil nitrogen availability in native and cheatgrass-dominated arid rangelands

Creator:: Harrison, Kristen S.
Abstract:: As large-scale restorations of degraded rangelands are initiated, land managers need to understand how decades of dominance by the invasive annual grass, cheatgrass (Bromus tectorum L.), have altered ecosystem processes. One way to assess such alterations is by observing differences in decay rates, since decomposition is determined by factors such...
Resource Type:: Masters Thesis

Variation of drought resistance and root regeneration among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana)

Creator:: Sharpe, Jodie M.
Abstract:: Drought resistance among genotypes of Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murr.) Pan., Cupressaceae) seedlings was evaluated both in the field and in the greenhouse. Field water potentials (Ψ) of 5-year-old seedlings were measured at two high-elevation plantation sites where summer drought occurs. Measurements of Ψ were compared to survival two years...
Resource Type:: Masters Thesis

Potential susceptibility of tanoak associated and rare ericaceous plant species of southwestern Oregon to Phytophthora ramorum

Creator:: Zanzot, James W.
Abstract:: The sudden oak death pathogen, Phytophthora ramorum, is present in southwestern Oregon, and while an eradication effort is underway, the potential impact of the polyphagous pathogen on surrounding vegetation is unknown. Plant communities in the area are substantially different from those affected in California, although tanoak (Lithocarpus densiflorus), evergreen huckleberry...
Resource Type:: Masters Thesis

Effect of iron on biological control of fire blight by Pseudomonas fluorescens A506

Creator:: Temple, Todd N.
Abstract:: Competitive exclusion has been the mechanism hypothesized to account for the biological control of fire blight disease of pear and apple by the bacterium Pseudomonas fluorescens A506 (A506). Recent laboratory assays demonstrated, however, that A506 produces an antibiotic that is toxic to the fire blight pathogen, Erwinia amylovora, when cultured...
Resource Type:: Masters Thesis

The effects of native plants on non-native plant abundance in a restoration setting : differences among native species and the predictive ability of species traits

Creator:: Goodridge, Jennifer M.
Abstract:: Reducing the cover of non-native species is one of the challenges of ecosystem restoration. The goal of this study is to identify native species traits that will increase native species cover and reduce non-native species cover in the first growing season at upland and wetland prairie restoration sites. Native and...
Resource Type:: Masters Thesis

Understory herb and shrub responses to root trenching, pre-commercial thinning, and canopy closure in Douglas-fir forest of the western Cascades, Oregon

Creator:: Lindh, Briana C.
Abstract:: This thesis examines factors limiting understory herb presence and flowering in young second-growth Douglas-fir (Pseudotsuga menziesii) forests on the west side of the Cascade Mountains, Oregon, USA. I studied the belowground effects of canopy trees on understory herbs and shrubs in old-growth forests using trenched plots from which tree roots...
Resource Type:: Dissertation

Genetic diversity of populations of Astragalus oniciformis using inter-simple sequence repeat (ISSR) markers

Creator:: Alexander, J. Andrew
Abstract:: Astragalus oniciformis Barneby is a xerophyte of the sagebrush deserts of central Idaho. It is a narrow endemic of the upper Snake River Plains where it inhabits stabilized, aeolian sand deposits over Quaternary basalt flows. The objective of this study was to determine the levels and distribution of genetic differentiation...
Resource Type:: Masters Thesis

Characterization, epidemiology, and ecology of a virus associated with black raspberry decline

Creator:: Halgren, Anne B.
Abstract:: The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms of black raspberries and was named Black raspberry decline associated virus (BRDaV). Double stranded RNA extraction from BRDaV-infected black raspberry...
Resource Type:: Dissertation

Foliar respiration in an old-growth coniferous forest

Creator:: Cooper, Clifton E.
Abstract:: Foliar respiration forms a large component of the carbon balance of any coniferous forest. We examine seasonal, interannual, spatial and interspecific variation of foliar maintenance respiration in a forest in Washington, USA, with measurements made quarterly for >4 years on 400-year old trees of Pseudotsuga menziesii, Tsuga heterophylla and Thuja...
Resource Type:: Dissertation

Systematics and phylogeny of Cordyceps and the Clavicipitaceae with emphasis on the evolution of host affiliation

Creator:: Sung, Gi-Ho
Abstract:: Cordyceps is a genus of perithecial ascomycetes. It includes over 400 species that are pathogens of arthropods and parasites of the truffle genus Elaphomyces. Based on the morphology of cylindrical asci, thickened ascus apices and filiform ascospores, it is classified in the Clavicipitaceae (Hypocreales), which also includes endophytes and epiphytes...
Resource Type:: Dissertation

Resistance mechanisms of Port-Orford-cedar to Phytophthora lateralis

Creator:: Oh, Eunsung
Abstract:: Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal agent of root disease, begins by screening, through artificial inoculation, phenotypically resistant trees selected from natural stands. The successful program selected tolerant or resistant POC parent trees for the purpose of disease management. Candidate resistant POCs were used in my dissertation...
Resource Type:: Dissertation

Sweet corn decline syndrome in Oregon's Willamette Valley

Creator:: Hoinacki, Elisabeth V.
Abstract:: For the past several years vegetable growers in Oregon's Willamette Valley have experienced reduced yields in their sweet corn plantings. We conducted studies to 1) describe the symptomology and etiology of the disease, 2) test a root rot rating system we developed to evaluate factors in the disease syndrome, and...
Resource Type:: Dissertation

Studies on the etiology and epidemiology of bull's eye rot of pears

Creator:: Henriquez, Jose Luis, 1961-
Abstract:: The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
Resource Type:: Dissertation

Riparian lichens of northern Idaho

Creator:: Hutchinson, Jenifer L.
Abstract:: Riparian forests in the Idaho Panhandle, north of Whitebird, were surveyed for rare riparian lichen species. The region was stratified into nine geographic units and by stream size. Eighty-one plots were surveyed for lichen community, stand and river characteristics. Variables important to lichen community composition included regional differences, elevation, climatic...
Resource Type:: Masters Thesis

Bioindication of air quality in forests of northern and central California using epiphytic macrolichen communities

Creator:: Jovan, Sarah
Abstract:: The unifying purpose of this dissertation was to describe, model, and map relationships between epiphvtic macrolichen communities and air quality in Ibrests of northern and central California. First, multivariate analyses were used to subdivide the large study area into three model areas with similar climate, topography, and lichen communities: the...
Resource Type:: Dissertation

Ecophysiology of the cyanolichen Lobaria oregana

Creator:: Antoine, Marie E.
Abstract:: This thesis consists of three manuscripts describing ecophysiological research on the cyanolichen Lobaria oregana. The first manuscript includes a re-evaluation of the assumptions underlying past estimates of N fixation by this species and provides an estimate of annual N fixation at the Wind River Canopy Crane (WRCC). Based upon litterfall...
Resource Type:: Masters Thesis

Seedborne Phytophthora infestans : effect of pathogen clonal lineage and potato cultivar on seed transmission of late blight and plant growth responses

Creator:: Partipilo, Heather M.
Abstract:: Seed piece to plant transmission of the potato late blight pathogen, Phytophthora infestans, occurred with isolates of the clonal lineages US-8 in Oregon and US-11 in Washington in field trials. Average transmission rate across potato cultivars was 0.5 and 2.4% with US-8, and 0.8 and 1.0% with US-11 in 1999...
Resource Type:: Masters Thesis

Impacts of ponderosa pine forest restoration treatments on the ectomycorrhizal fungal community and fine root biomass in the Blue Mountains of Oregon

Creator:: Smith, Jane E. (Jane Elizabeth)
Abstract:: Before the arrival of Euro-Americans, the inland Pacific Northwest was settled by native people whose frequent intentional burning of the landscape promoted open stands dominated by large fire-resistant ponderosa pine. Fire suppression for nearly a century, livestock grazing, and logging of the largest trees has resulted in forests characterized by...
Resource Type:: Dissertation

Characteristics of soil organic matter in two forest soils

Creator:: Crow, Susan E.
Abstract:: Soil organic matter (SOM) is the terrestrial biosphere's largest pool of organic carbon (C) and is an integral part of C cycling globally. Soil organic matter composition typically can be traced directly back to the type of detrital inputs; however, the stabilization of SOM results as a combination of chemical...
Resource Type:: Dissertation

Systematics, phylogeny, and biogeography of the hysterangiales and related taxa (Phallomycetidae, Homobasidiomycetes)

Creator:: Hosaka, Kentaro
Abstract:: Monophyly of the gomphoid-phalloid clade was confirmed based on multigene phylogenetic analyses. Four major subclades (Hysterangiales, Geastrales, Gomphales and Phallales) were also demonstrated to be monophyletic. The interrelationships among the subclades were, however, not resolved, and alternative topologies could not be rejected statistically. Nonetheless, most analyses showed that the Hysterangiales...
Resource Type:: Dissertation

Phylogenetics and genomic patterns of speciation in Pinus with an empahsis on subgenus Strobus

Creator:: Syring, John V.
Abstract:: Data from nuclear ribosomal internal transcribed spacer regions (nrITS) and chloroplast DNA (cpDNA) have failed to resolve phylogenetic relationships in Pinus. To provide greater interspecific resolution, five low-copy nuclear genes were developed from mapped conifer anchor loci. Four genes were sequenced from species representing all Pinus subsections. Individual loci do...
Resource Type:: Dissertation

Identification and characterization of seven ROP GTPases in Zea mays

Creator:: Christensen, Todd M.
Abstract:: Regulation of cell division and expansion are critical for plant development. The mechanisms that control these processes are not clearly understood in higher plants. In other eukaryotic models it has been shown that the highly conserved Rho family GTPases play a crucial role in these mechanisms. One distinct subset of...
Resource Type:: Masters Thesis

Establishment tolerance of six native sagebrush steppe species to imazapic (PLATEAU®) herbicide implications for restoration and recovery

Creator:: Bekedam, Steven
Abstract:: Scientists and land managers realize that integrated weed management (IWM) strategies are needed to attain successful and lasting improvements of weed infested landscapes. At this time no broadly reliable and environmentally safe IWM strategy has been developed to control exotic annual grasses that dominate many ecosystems of the northern Great...
Resource Type:: Masters Thesis

Pathways of infection of Phytophthora ramorum in rhododendron

Creator:: Lewis, Carrie D.
Abstract:: Phytophthora ramorum, a plant pathogen, is the cause of sudden oak death and ramorum blight and shoot die-back. It has a wide host range including many native forest species and common nursery plants. The lack of knowledge regarding infection biology of P. ramorum limits our understanding of its ecology and...
Resource Type:: Masters Thesis

Systematics of the genus Torrubiella

Creator:: Johnson, Desiree M.
Abstract:: Torrubiella is a genus of entomopathogenic fungi in the Clavicipitaceae (Ascomycota). Species of the genus produce superficial perithecia on a loose mat of hyphae that forms directly on the host. The genus is estimated to contain about 70 species. Torrubiella is hypothesized to be a close relative of Cordyceps because...
Resource Type:: Masters Thesis

Modeling disease gradients and understanding the spread of wheat stripe rust using simulated epidemics

Creator:: Sackett, Kathryn E.
Abstract:: Primary disease gradients of wheat stripe rust, caused by the aerially dispersed fungal pathogen Puccinia striformis, were measured in Madras and Hermiston, OR in the springs of 2002 and 2003. Disease foci were created by inoculating a 1.52m x 1.52m area in each of three replicate field plots (6.1m wide...
Resource Type:: Masters Thesis

Studies to facilitate reintroduction of golden paintbrush (Castilleja levisecta) to the Willamette Valley, Oregon

Creator:: Lawrence, Beth A.
Abstract:: Golden paintbrush (Castilleja levisecta Greenman) historically inhabited the prairies of the Willamette Valley, Oregon. However, this Pacific Northwest endemic is currently restricted to eleven sites in the Puget Trough of Washington and British Columbia. Recovery criteria call for the establishment of new populations throughout the species historic range, including the...
Resource Type:: Masters Thesis

Comparison of the water relations characteristics of woody plants in western Oregon

Creator:: Davis, Kent J.
Abstract:: I studied the water relations traits, twig conductivity, C'3 isotopic composition, and wood density of three conifer and five angiosperm species in western Oregon. This study took place from spring 2002 to fall 2003 on four sites. Species were selected to represent the diversity of drought tolerance of woody plants...
Resource Type:: Masters Thesis

Susceptibility of golden chinquapin (Chrysolepis chrysophylla) to Phytophthora cambivora

Creator:: Saavedra, Angel Luis
Abstract:: In early 2000, unusual mortality of a native North American tree, golden chinquapin, was reported by the USDA-Forest Service. Dying trees exhibited girdling cankers in the inner bark of the lower bole, branch flagging and defoliation. Isolations from necrotic tissues and soil associated with diseased or killed trees yielded Phytophthora...
Resource Type:: Masters Thesis

The effects of defoliation on Bromus tectorum seed production and growth

Creator:: Mayer, Kara Hempy
Abstract:: Cheatgrass (Bromus tectorum L.) is a widespread exotic weed in the Intermountain sagebrush steppe. An annual grass, it is highly prolific and very competitive with native perennial grass seedlings. A clipping experiment carried out at two cheatgrass-dominated sites (Lincoln Bench and Succor Creek) in eastern Oregon analyzed effects of defoliation...
Resource Type:: Masters Thesis

Hydromulch tackifier and sucrose effects on microbial nitrogen and Bromus tectorum biomass

Creator:: Perkins, Lora B.
Abstract:: There is growing interest in using nutrient manipulations to control invasive plants such as Brornus lectorurn L. (cheatgrass). Both labile (sucrose) and recalcitrant (straw and sawdust) carbon sources are added to the soil surface to reduce plant available soil N via soil microbial immobilization. However, the application rates used in...
Resource Type:: Masters Thesis

The fate of organic and inorganic nitrogen inputs in an old-growth forest of the central Oregon Cascade Range

Creator:: Holub, Scott M.
Abstract:: Forests in the Pacific Northwest receive very little nitrogen through atmospheric deposition and thus studying the nitrogen cycle in this region can provide insights into how the unpolluted nitrogen cycle functions. I examined the fate of organic nitrogen versus inorganic nitrogen and the effect of tamlins on N retention by...
Resource Type:: Dissertation

Lichen response to the environment and forest structure in the western Cascades of Oregon

Creator:: Martin, Erin P.
Abstract:: Lichens are an important part of the biota in western Oregon forests, where they perform valuable ecological roles and contribute significantly to biodiversity. Lichens in western Oregon are threatened by a number of factors including air pollution and land use practices. If we wish to maintain the persistence of lichens...
Resource Type:: Dissertation

Conservation biology of Plagiobothrys hirtus (Boraginaceae) : evaluation of life history and population enhancement

Creator:: Amsberry, Kelly
Abstract:: Plagiobothrys hirtus (Boraginaceae) is a state and federally listed endangered plant found only in Douglas County, Oregon. This vernal pool endemic has historically been threatened by agricultural conversion of seasonal wetlands in the Sutherlin area, and is currently being eradicated as habitat is lost due to the rapid urban development...
Resource Type:: Masters Thesis

Population viability analysis of endangered plant species : an evaluation of stochastic methods and an application to a rare prairie plant

Creator:: Kaye, Thomas N.
Abstract:: Transition matrix models are one of the most widely used tools for assessing population viability. The technique allows inclusion of environmental variability, thereby permitting estimation of probabilistic events, such as extinction. However, few studies use the technique to compare the effects of management treatments on population viability, and fewer still...
Resource Type:: Dissertation

The influence of prescribed fire on the rare endemic plant Delphinium pavonaceum (Peacock larkspur)

Creator:: McKernan, Brie-Anne
Abstract:: In the wetland prairie of William L. Finley National Wildlife Refuge (FNWR) in western Oregon, we investigated the response of Delphinium pavonaceum Ewan (peacock larkspur, Ranunculaceae), an endangered perennial forb, to four unreplicated dormant season fire regimes of 0, 2, 4, or 10 fires that were applied over a 12-year...
Resource Type:: Masters Thesis

Conservation of Sidalcea nelsoniana through habitat management : effects of burning, mowing, and altered flooding regime on a rare Willamette Valley perennial

Creator:: Bartels, Marilynn R.
Abstract:: Active habitat management plays a key role in the preservation of native ecosystems and rare species, especially in the Willamette Valley of Oregon, where natural succession to woodlands threatens the few wetland prairies remaining after 150 years of agriculture and urbanization. Sidalcea nelsoniana, listed as threatened under the federal Endangered...
Resource Type:: Masters Thesis

Impacts of fuel reduction thinning treatments on oak and chaparral communities of southwestern Oregon

Creator:: Perchemlides, Keith A.
Abstract:: In response to concerns about excessive stand densities and high-severity wildfires, land managers in the western United States are carrying out extensive programs of fuel reduction thinning. How will these sudden reductions in canopy cover and associated changes in habitat affect native and exotic herbaceous vegetation and canopy species regeneration?...
Resource Type:: Masters Thesis

The effects of two fuel reduction treatments on chaparral communities in southwest Oregon

Creator:: Sikes, Kendra G.
Abstract:: Fuel reduction treatments are being applied to public lands, affecting significant acreage at considerable expense. This study compares the short term effects on a chaparral plant community of two different fuel reduction methods, brush mastication and "hand piling and burning" (HPB). Ceanothus cuneatus dominated the southwestern Oregon study sites where...
Resource Type:: Masters Thesis

An Enthnobotanical Analysis of Basketry

Creator:: Fluharty, Suzanne M.
Abstract:: The focus of my thesis is ethnobotany which seeks to examine botanical resources and their context within particular cultures. My ethnographic research identifies and interprets the cultural processes woven into Oregon's coastal basketry through spirituality, environmental habitats, and utilized plant species. This is augmented with botanical research addressing the question...
Resource Type:: Masters Thesis

Histological examination of Phytophthora ramorum in Notholithocarpus densiflorus bark tissues

Creator:: Botts, Molly M.
Abstract:: Colonization of N. densiflorus tissues by P. ramorum is not well understood. The pathogen is able to colonize nearly all tissues of this host but it is unclear how a tree is ultimately killed. Because this is such a destructive invasive pathogen, it is important to investigate its pathogenic strategy....
Resource Type:: Masters Thesis

Applying GIS Analysis to Herbarium Georeferencing

Creator:: Buonopane, Michelle
Abstract:: In March 2005 the Oregon State University Herbarium launched its new, free online Oregon Vascular Plant Atlas for public use. This Atlas allows users to access location information from over 385,000 vascular plant specimen and observation records in the state of Oregon. The potential applications of such spatial information are...
Resource Type:: Capstone Project

Conservation and Land Management : Seeds of Success, New Mexico

Creator:: Weller, Stacey A.
Abstract:: The Seeds of Success (SOS) is a wildland seed collection program in support of the interagency Native Plant Materials Development Program (NPMP) and in partnership with the global conservation initiative, the Millennium Seed Bank Project of the Royal Botanic Gardens, Kew. SOS collections follow a set protocol with consideration for...
Resource Type:: Capstone Project

Willamette Valley Prairie Restoration : The Native Seed Network and Sidalcea

Creator:: Lambert, Joshua K.
Abstract:: My internship was conducted with the Native Seed Network program within the Institute for Applied Ecology, a non-profit organization located in Corvallis, whose focus is education, applied research and active restoration and of native ecosystems. My internship goals were to increase my experience in applied restoration ecology and conservation biology...
Resource Type:: Capstone Project

Conservation and Community Development in Nepal : Case Study of a Non-government Organization

Creator:: Cannon, Joseph R.
Abstract:: The internship I performed was with Rural Community Development Program (RCDP), a domestic non-governmental organization in the country of Nepal. This organization focuses on community development goals in rural communities, utilizing the efforts of volunteers within the context of environmental conservation ideals. I primarily worked with the associated community plant...
Resource Type:: Capstone Project

Conservation genetics of Kincaid's lupine : a threatened plant of western Oregon and southwest Washington grasslands

Creator:: Severns, Paul M.
Abstract:: Kincaid's lupine (Lupinus oreganus Heller) is a federally listed threatened species native to remnant grassland of western Oregon and southwestern Washington, and is the primary larval host plant of a once thought extinct butterfly, Plebejus icarioides fenderi Macy. Past studies concerning Kincaid's lupine reproduction suggested that populations may suffer reductions...
Resource Type:: Dissertation

Chaparral history, dynamics, and response to disturbance in southwest Oregon : insights from age structure

Creator:: Duren, Olivia
Abstract:: Fuels management on Bureau of Land Management lands in SW Oregon, USA, is motivated by the needs to reduce fire hazard and restore ecosystems thought to be impacted by fire suppression. Chaparral is one of the most characteristic vegetation communities of SW Oregon's interior valleys, and extensive acreages within this...
Resource Type:: Masters Thesis

Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae)

Creator:: Campanella, Donald M.
Abstract:: A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...
Resource Type:: Dissertation

Performance of Willamette Valley native plants following herbicide exposure

Creator:: Blakeley-Smith, Matthew R.
Abstract:: Prairies were once the dominant vegetation type in Oregon's Willamette Valley. Land use conversion, fire suppression, succession, and invasive species have reduced Willamette Valley prairies to less than 1% of their historical area. The remnant prairies that persist today are small in size and are highly fragmented. Marginal strips of...
Resource Type:: Masters Thesis

Generation of full-length cDNA clone and functional analysis of leader proteases of grapevine leafroll-associated virus-2

Creator:: Liu, Yu-Ping
Abstract:: Papain-like leader proteases are found in diverse families of human, animal, plant, and fungal positive-strand RNA viruses. In addition to autocatalytic processing, these proteases play a variety of roles in the virus life cycle. In particular, the leader protease (L-Pro) of a prototype member of the Closterovirus genus, Beet yellows...
Resource Type:: Dissertation

Developing techniques for evaluating the susceptibility of root-disease resistant Port-Orford-Cedar to foliar and stem canker diseases.

Creator:: Martin, Danielle K. H.
Abstract:: Since around 1923 Port-Orford-cedar (Chamaecyparis lawsoniana (A. Murray) Parl.) has been affected by Phytophthora root disease caused by the virulent introduced pathogen Phytophthora lateralis. A systematic resistance testing and breeding program located at the USDA Forest Service Dorena Genetic Resource Center in Cottage Grove, Oregon was initiated in 1997 with...
Resource Type:: Masters Thesis

Epiphytic macrolichens in relation to forest management and topography in a western Oregon watershed

Creator:: Berryman, Shanti D.
Abstract:: This dissertation describes patterns in epiphytic macrolichen community composition, diversity, and biomass across various stand types in the Blue River watershed of western Oregon. It first examines the relative importance of ecological factors such as stand age, remnant tree retention, and topography to lichen communities in the landscape. It then...
Resource Type:: Dissertation

Compost teas and compost amended container media for plant disease control

Creator:: Scheuerell, Steven J.
Abstract:: The primary goal of this dissertation research was to assess the use of compost for the control of several foliar and soil borne diseases commercially important in the Pacific Northwest. The use of compost teas to control of gray mold (Botrytis cinerea) on geraniums, powdery mildew (Podosphearapannosa var. rosae), rust...
Resource Type:: Dissertation

Conservation biology of Perideridia erythrorhiza (Apiaceae) : experimental reintroduction and life history

Creator:: Roberts, Kimberly A.
Abstract:: An experimental reintroduction was performed to determine the best method to create new populations of the tuberous species Perideridia erythrorhiza, a rare vascular plant endemic to southern Oregon. Only a handful of sites are currently present, and many of these are subject to other land uses such as urban development...
Resource Type:: Masters Thesis

A fistful of Astragalus : phenotypic and genotypic basis of the most taxon rich species in the North American flora

Creator:: Knaus, Brian J.
Abstract:: The study of the infra-specific ranks (i.e., subspecies and variety) can be considered the study of the process of speciation. Astragalus lentiginosus Douglas ex Hooker (Fabaceae) is the most taxon rich species in the U.S. flora currently including 40 taxonomic varieties. These varieties were described using traditional taxonomic methods primarily...
Resource Type:: Dissertation

The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood

Creator:: Collins, Bradley R.
Abstract:: Tanoak (Lithocarpus densiflorus), along with some other members of Fagaceae, are susceptible to sudden oak death caused by the oomycete Phytophthora ramorum. Symptoms of the disease include dying crowns, bleeding cankers, and eventually death of infected trees. The cause of mortality is not well understood, but recent research indicates that...
Resource Type:: Masters Thesis

Biotic soil crusts of Oregon's shrub steppe

Creator:: Ponzetti, Jeanne M.
Abstract:: This research examines the community composition of biotic soil crusts at nine sites in central and eastern Oregon, U.S.A. At each site, data were collected in one pair of livestock-grazed and excluded transects. Variables recorded included: cover of biotic soil crusts and vascular plant species, soil surface pH, electrical conductivity,...
Resource Type:: Masters Thesis

Serpentine and non-serpentine edaphic ecology and the recovery of Lomatium cookii (Apiaceae), an endangered endemic of southwest Oregon

Creator:: Silvernail, Ian S.
Abstract:: The role of unusual geologies in plant distribution and form is well-known. Serpentine (ultramafic) soils exert a particularly strong influence on plants, as evidenced by a high level of endemism and the morphological and physiological traits displayed in adaptation to the extraordinary chemistry of these substrates. Adaptation may lead to...
Resource Type:: Masters Thesis

Susceptibility of coast redwood seedlings to Phytophthora ramorum

Creator:: Lucas, Sunny L.
Abstract:: Coast redwood (Sequoia sempervirens) (D. Don) Endl. is a host for Phytophthora ramorum but it was unclear if the pathogen represents a significant disease risk to this tree species. In this study the susceptibility of coast redwood seedlings and the likelihood of sporulation on redwood were examined. Two methods were...
Resource Type:: Masters Thesis

A taxonomic revision of Astragalus mokiacensis and allied taxa within the Astragalus lentiginosus complex of Section Diphysi

Creator:: Alexander, J. Andrew
Abstract:: North America, with over 400 species of Astragalus (Fabaceae), is one of three major centers of diversity, all of which comprise the majority of the nearly 1750 species of Astragalus worldwide. One of the most diverse species, Astragalus lentiginosus of Section Diphysi, is a polymorphic complex of over 40 varieties,...
Resource Type:: Dissertation

Yield responses of invasive grasses to carbon doses

Creator:: Brunson, Jessi L.
Abstract:: The sagebrush steppe ecosystem of the northern Great Basin is severely degraded and continues to decline due in large part to the invasive, non-native annual grasses Bromus tectorum L. (cheatgrass) and Taeniatherum caput-medusae (L.) Nevski (medusahead). Restoration of invasive-dominated areas is difficult, but can be enhanced by adding a carbon...
Resource Type:: Masters Thesis

The effects of site preparation on native forb establishment in a wet prairie, Willamette Valley, Oregon

Creator:: Norman, Katherine N.
Abstract:: Wetlands and wet prairies are economically and environmentally valuable ecosystems, but many have been degraded or converted to other uses. As human understanding of wetlands' value has increased, restoration efforts have grown correspondingly. Restoration attempts use a diversity of methods, which often include seeding with native plant species. This thesis...
Resource Type:: Masters Thesis

Terrestrial lichen and bryophyte communities of the Blue Mountains in Northeast Oregon

Creator:: Hardman, Amanda
Abstract:: Although terrestrial lichens and bryophytes are common in upland plant communities of the Blue Mountains in northeast Oregon, research on cryptogam communities in this region is wanting. Studies have shown that lichens and bryophytes can reduce soil erosion and increase soil fertility in other semiarid habitats of North America. Understanding...
Resource Type:: Masters Thesis

Reproductive isolation and interspecific hybridization in the threatened species, Sidalcea nelsoniana

Creator:: Gisler, Steven D.
Abstract:: In addition to its longstanding recognition as an influential evolutionary process, interspecific hybridization is increasingly regarded as a potential threat to the genetic integrity and survival of rare plant species, manifested through gamete wasting, increased pest and disease pressures, outbreeding depression, competitive exclusion, and genetic assimilation. Alternatively, hybridization has also...
Resource Type:: Masters Thesis

Understanding sporulation and dissemination of Podosphaera macularis, hop powdery mildew

Creator:: Peetz, Amy B.
Abstract:: Podosphaera macularis causes one of the most important diseases, powdery mildew, of Humulus lupulus (hop). If left unmanaged, hop powdery mildew can cause total crop loss due to disease or browning of hop cones rendering the cones unmarketable to buyers. The Hop Powdery Mildew Infection Risk Index (HOPS) is heavily...
Resource Type:: Masters Thesis

Functional groups, traits, and the performance of species in restoration

Creator:: Roberts, Rachael E. (Rachael Elaine)
Abstract:: In ecological restoration, species that are sown to increase the native plant diversity range in establishment ability. Some species readily establish, while others rarely do. This study set out to investigate some of the potential processes influencing species establishment, as well as the traits that are associated with the success...
Resource Type:: Masters Thesis

Biology of chlamydospores of Phytophthora ramorum

Creator:: Smith, Aaron Lee
Abstract:: The chlamydospore is a survival spore produced by 35 of the 75 described species of Phytophthora. Phytophthora ramorum Werres, de Cock & Man in't Veld, the causal agent of Sudden Oak Death (SOD), produces abundant chlamydospores in artificial culture and plant tissue. The chlamydospore is likely the most important survival...
Resource Type:: Masters Thesis

New perspectives on evolutionary relationships within Pinus (Pinaceae) and within subsection Ponderosae (subgenus Pinus)

Creator:: Willyard, Ann Nachreiner
Abstract:: A fossil-calibrated phylogenetic framework based on exemplars from each of the four taxonomic sections within Pinus was created using multiple nuclear and chloroplast loci. Calibration at the well-defined subgeneric split within Pinus with either fossil leaves and cones (ca. 45 million years ago) or fossil wood (ca. 85 million years...
Resource Type:: Dissertation

Biology and management of Meloidogyne chitwoodi using oxamyl on potato in the western United States

Creator:: David, Nicholas L.
Abstract:: Field trials were conducted during 2001 to 2003 to investigate soil population dynamics of Meloidogyne chitwoodi, tuber symptom suppression using oxamyl, and post-harvest tuber symptom development on short-season potato varieties Russet Norkotah and Russet Nugget (San Luis Valley only). The experiments were located in the San Luis Valley in Colorado,...
Resource Type:: Dissertation

The influence of pollinators on the maintenance of mixed mating in a population of the blue columbine, Aquilegia coerulea (Ranunculaceae)

Creator:: Sweet, Heather R.
Abstract:: Pollination ecology may play an important role in the maintenance of selfing in populations of self-compatible hermaphroditic plants where both selfing and outcrossing occur (mixed mating). Behavior and abundance of pollinators can influence the two major modes of selfing; autogamy (selfing within a flower) and geitonogamy (selfing between flowers on...
Resource Type:: Masters Thesis

Responses and relationships among Fusarium species, sweet corn, and western spotted cucumber beetles

Creator:: Miller, Nathan L. (Nathan Louis)
Abstract:: Sweet corn (Zea mays L.) yields in the Willamette Valley of Oregon have been declining since the early 1990’s. Studies were done to determine if there is a relationship between ear weight and several disease parameters including necrotic crowns or stalk nodes, nodal root rot, radicle root rot, and sub-crown...
Resource Type:: Dissertation

Characterization of the molecular foundations and biochemistry of alkane and ether oxidation in a filamentous fungus, a Graphium species.

Creator:: Skinner, Kristin M.
Abstract:: Graphium sp., a eukaryotic alkanotroph, is able to oxidize small-molecular weight gaseous n-alkanes, diethyl ether and the branched ether, methyl tert butyl ether (MTBE). However, information regarding the biochemistry of fungal-mediated alkane and ether metabolism is limited, and questions regarding the identity of alkane oxidation catalysts and the genetic underpinnings...
Resource Type:: Dissertation

Biology of sweet cherry powdery mildew

Creator:: Calabro, Jill M.
Abstract:: The Pacific Northwest has become one of the nation’s premier sweet cherry, Prunus avium, production areas. As production of sweet cherries has flourished in Oregon and Washington, so has powdery mildew, caused by the fungus Podosphaera clandestina, which infects both foliage and fruit causing severe economic damage to growers. Sweet...
Resource Type:: Dissertation

Conservation of Oenothera wolfii (Onagraceae) : introducing a threatened plant into two protected locations in Oregon

Creator:: Currin, Rebecca E.
Abstract:: The showy biennial to short-lived perennial Oenothera wolfii (Munz) Raven, Dietrich & Stubbe (Wolf’s evening primrose) occurs in only a small number of isolated populations on the southern Oregon and northern California coast. This rare species is currently listed as Threatened in Oregon, and is considered a Species of Concern...
Resource Type:: Masters Thesis

Community gradients of Arctic macrolichens in relation to succession, grazing and the environment

Creator:: Holt, Emily A.
Abstract:: The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared following disturbance were derived from the literature. Weighted averaging of these data with a community matrix created a successional score for each sample...
Resource Type:: Dissertation

Specificity of quantitatively expressed host resistance to Mycosphaerella graminicola

Creator:: Krenz, Jennifer E.
Abstract:: The specificity of quantitative host resistance to plant disease has long been a controversial issue. We examined interactions between wheat (Triticum aestivum) and Mycosphaerella graminicola, causal agent of Septoria tritici blotch, to determine whether specific interactions occur between host and pathogen genotypes that could be involved in eroding quantitatively expressed...
Resource Type:: Masters Thesis

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