Index Catalog // ScholarsArchive@OSU

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
Full Text:: Pinus). Abstract approved: Aaron I. Liston

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
Full Text:: approved: 7 i/ David A, Pyke and Mark V. Wilson Cheatgrass (Bromus tectorum L.) is a widespread exotic

Models of a four-species annual weed community : growth, competition, and community dynamics

Creator:: Roush, Mary Lynn
Abstract:: Models of weed communities aid in the development of weed management strategies and elucidate the processes and mechanisms that regulate plant populations and communities. A conceptual weed community model was developed to organize key regulatory life-history processes. Specific investigations focused on the processes of plant growth and competition, and relationships...
Resource Type:: Dissertation
Full Text:: approach to answer this question. Dr. M.V. Wilson, Dr. S.R. Radosevich, and I have colla- borated to

Restructuring of land and community in the remote rural west : the case of Wallowa County, Oregon

Creator:: Abrams, Jesse
Abstract:: Since at least the 1970s, rural areas in the western United States, as elsewhere across the country and world, have been subject to social, economic, and political forces that have resulted in novel demographic and land tenure trends when compared to previous decades. Collectively, these processes of restructuring have created...
Resource Type:: Dissertation
Full Text:: conflict regarding the legitimacy of various claims on rural space. In this case study, I examine in

A characterization of seasonal pools in Central Oregon's high desert

Creator:: Dlugolecki, Laura
Abstract:: Seasonal wetlands in arid and semi-arid lands provide an important source of surface water in otherwise dry lands. Central Oregon's high desert, located in the Northern Great Basin (NGB) is dotted with hundreds of seasonal pools, locally called playas. The playas hold water or snow during parts of winter and...
Resource Type:: Masters Thesis
Full Text:: landscape I explored various methods to characterize and monitor the playas. I analyzed field data

Greater sage-grouse reproductive ecology : linkages among habitat resources, maternal nutrition, and chick survival

Creator:: Gregg, Michael A.
Abstract:: Greater sage-grouse (Centrocercus urophasianus) populations declined range wide during the past 50 years. Grouse populations were 2-3 times larger than the current population as recently as the early 1970's. In addition to habitat loss and fragmentation, declines were attributed habitat degradation that caused reduced productivity. Because chick survival remains the...
Resource Type:: Dissertation
Full Text:: , Zach Turnbull, Matt Wilson, Mark Westbrock, Nate Woodard, Jamie Woodring, and Jason Zoller. Finally, I

Directing ecological succession : the role of competition in restoring semi-arid grasslands dominated by invasive plants

Creator:: Mangla, Seema
Abstract:: Successful ecosystem restoration requires an understanding of the ecological processes directing succession. One of the challenges in the semi-arid grasslands of western United States is replacement of native species by invasive annual grasses. Solutions to this problem require identifying and manipulating ecological processes that direct succession to favor desired vegetation....
Resource Type:: Dissertation
Full Text:: early phase of establishment, I performed a diallel competition experiment with species grown either

Disturbance and dynamics of riparian forests in southwestern Oregon

Creator:: Messier, Michael S.
Abstract:: Fire exclusion has been associated with structural and compositional changes in many upland forests of the western United States, but little is known about the impacts on riparian forests, portions of the landscape protected for habitat and water quality. For this study, I characterized the historic disturbance and tree recruitment...
Resource Type:: Masters Thesis
Full Text:: and water quality. For this study, I characterized the historic disturbance and tree recruitment

Associations Between Crested Wheatgrass and Native Vegetation in Southeastern Oregon : An Investigation of Co-establishment, Environment, Seeding History, and Livestock management

Creator:: Nafus, Aleta M.
Abstract:: Crested wheatgrass (Agropyron cristatum [L] Gaertm), an introduced bunchgrass, has been seeded on over 5 million hectares of degraded rangeland in western North America because it establishes more readily than native bunchgrasses. Because crested wheatgrass stands are associated with native species displacement and low biological diversity, there is substantial interest...
Resource Type:: Dissertation
Full Text:: first study, I examined the abundance of crested wheatgrass and seven native sagebrush steppe

Growth characteristics and site potentials of perennial grass species

Creator:: Borman, Michael M.
Abstract:: In this study I assessed the potentials of selected, established perennial grasses to maintain site occupancy in the foothills ecosystem of the Rogue River Valley of southwest Oregon which is currently dominated by a variety of annual plants. The first evaluation compared growth curves of the perennial grasses and contrasted...
Resource Type:: Dissertation
Full Text:: study I assessed the potentials of selected, established perennial grasses to maintain site occupancy

Climate-growth relationships of western juniper and ponderosa pine at the pine-woodland ecotone in southern Oregon

Creator:: Knutson, Kevin C.
Abstract:: Pinyon-juniper woodlands throughout the western U.S. have expanded rapidly following European settlement during the late 19th century. In central and eastern Oregon, western juniper (Juniperus occidentalis var. occidentalis Hook.) encroachment has been previously documented in the sagebrush steppe and upper elevation aspen communities. While these vegetation changes and dynamics have...
Resource Type:: Masters Thesis
Full Text:: is likely. I sought to address this problem at the pine-woodland ecotone using tree-ring data

Role of propagule pressure and priority effects on plant establishment during restoration of invaded shrub-steppe

Creator:: Schantz, Merilynn C.
Abstract:: Biological plant invasions are diminishing the ecological integrity and function of ecosystems worldwide. A primary example of this is in the Great Basin of the United States, where invasive annual grasses, like cheatgrass (Bromus tectorum L.) and medusahead (Taeniatherum caput-medusae L. Nevski), are dominating many sagebrush-steppe ecosystems. In these invaded...
Resource Type:: Dissertation
Full Text:: , and annual grass dispersal timing, I conducted a factorially arranged experiment that tested the

Vegetation composition and response to fire of native Willamette Valley wetland prairies

Creator:: Pendergrass, Kathy L. (Connelly)
Abstract:: Fires set by Native Americans were important in shaping and maintaining Willamette Valley prairie plant communities. With fire exclusion after Euro-American settlement in the 1840's, composition of the remaining prairies shifted toward shrub and tree dominance with a concomitant decline in endemic prairie plant populations. I hypothesize that by restoring...
Resource Type:: Masters Thesis
Full Text:: Waterways Experiment via Mark V. Wilson for supplying additional financial support that I might exist

Influence of silvicultural treatments, overstory, and understory vegetation on quaking aspen (Populus tremuloides) regeneration in southeastern Idaho

Creator:: Muñoz, Bethany L.
Abstract:: Quaking aspen (Populus tremuloides Michx.) is known to be a widely distributed, shade-intolerant and short-lived hardwood found in both seral, even-aged and stable, uneven aged stands. There have been reports of extensive aspen mortality, crown thinning, and branch dieback across North America that have been linked to the occurrence of...
Resource Type:: Masters Thesis
Full Text:: resilience within quaking aspen stands with changing ecological conditions. For this thesis I focused on a

Demography of medusahead on two soil types : potential for invasion into intact native communities

Creator:: Miller, Heather C.
Resource Type:: Masters Thesis
Full Text:: I understand that my thesis will become part of the permanent collection of Oregon State University

Farmer perspectives on success and challenges : a study of small farms in Oregon's Willamette Valley

Creator:: Pool, Kristin E.
Abstract:: This thesis investigates the success of and challenges facing small farmers operating direct marketing farm businesses in Oregon's Willamette Valley. This qualitative study utilizes participatory methods to gain the unique perspectives of small farmers regarding their success and challenges. Small farms are important players in local food systems and ensuring...
Resource Type:: Masters Thesis
Full Text:: the Graduate School I understand that my thesis will become part of the permanent collection of

Intercropping trees in a vegetable production systems : a holistic inquiry

Creator:: Seiter, Stefan
Resource Type:: Dissertation
Full Text:: lost to trees. A. rubra and I?. pseudoacacia green manure yields were low compared to tropical alley

An evaluation of biological control of Linaria dalmatica with Mecinus janthinus in Oregon

Creator:: Park, Alexander
Abstract:: Dalmatian toadflax (Linaria dalmatica) has become a prolific invasive plant of rangelands in Oregon since its arrival in the early 20th century. In 2001, the Oregon Department of Agriculture initiated a release program promoting the distribution of the stem-boring weevil, Mecinus janthinus as classical biological control agent to reduce densities...
Resource Type:: Masters Thesis
Full Text:: Science Graduate School Dean of the Graduate School I understand that my thesis will

Traditional ecological knowledge to develop and maintain fire regimes in northwestern California, Klamath-Siskiyou bioregion : management and restoration of culturally significant habitats

Creator:: Lake, Frank K.
Abstract:: The use of Native American fire regimes evolved in the Klamath-Siskiyou bioregion over millennia. A mixture of Native American and Euro-American socio-cultural management has developed from adaptations to climate, topography, ecological processes, and land use practices. This research incorporates Traditional Ecological Knowledge (TEK) to partially examine the role of tribal...
Resource Type:: Dissertation
Full Text:: ___________________________________________________________________ Dean of the Graduate School I understand that my dissertation will

Growth responses of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) to defoliation

Creator:: Osman, Khalid Amir
Abstract:: The effect of defoliation intensity and season on Douglas-fir growth were studied in three replications in the Siuslaw National Forest during 1988-1990. Four intensities of defoliation were applied once in either spring or summer 1988. Stem diameter and canopy area were linearly inversely proportional to the level of defoliation. Defoliation...
Resource Type:: Dissertation
Full Text:: contributed to the successful completion of this study. I would like to take this opportunity to thank each

Effects of wildfire burn severity on soil microbial communitiesand invasive plant species in the Cascade Range of Oregon

Creator:: Hebel, Cassie L.
Abstract:: Fire suppression in the last several decades has resulted in unprecedented accumulations of organic matter on the landscape, leading to an increase in large, intense wildfires. This study investigated the soil microbial community (using phospholipid fatty acid analysis) across recently burned forests on the eastern slope of the Cascade Range...
Resource Type:: Masters Thesis
Full Text:: Head of the Department of Forest Science Dean of the Graduate School I understand my

Spatial patterns of tree effects on pasture production in open canopied agroforests

Creator:: Harris, Norman Rex
Resource Type:: Masters Thesis
Full Text:: , representing Rangeland Resources Chair of Department of Rangeland Resources I understand that my thesis will

Effects of prescribed fire on Wyoming big sagebrush communities : implications for ecological restoration of sage grouse habitat

Creator:: Wrobleski, David W.
Resource Type:: Masters Thesis
Full Text:: School I understand that my thesis will become part of the permanent collection of Oregon State

Small broomrape (Orobanche minor) management using wheat (Triticum aestivum) as a false host

Creator:: Al-thahabi, Salam A.
Abstract:: Small broomrape (Orobanche minor) is an obligate, chlorophyll-lacking parasite that parasitizes red clover (Trifolium pratense) roots. This study was conducted to develop and implement an integrated, biologically based control program for small broomrape by using wheat as a false host to reduce the soil seed bank. The relationship between temperature...
Resource Type:: Dissertation
Full Text:: _____________________________________________________________________ Dean of the Graduate School I understand that my dissertation will become part of the

An Investigation of soil, vegetation and mycorrhizal characteristics associated with native grass re-esablishment in crested wheatgrass seedings

Creator:: Raven, Karen A.
Abstract:: Since the 1930's, many fields on the Crooked River National grasslands have been seeded to crested wheatgrass (Agropyron desertorum). While some of these fields remain dominated by crested wheatgrass others had a greater presence of deep rooted native perennial grasses such as bluebunch wheatgrass (Pseudoroegneria spicata). Twenty eight fields previously...
Resource Type:: Masters Thesis
Full Text:: !essor, representing Rangeland Resources Head of the Department of Dean I understand that my thesis

Persistence of western juniper resource islands following canopy removal

Creator:: Miwa, Christopher
Abstract:: Western juniper (Juniperus occidentalis) cover has more than doubled within the last century and currently occupies over 9 million acres in the Intermountain West. Encroachment has altered the spatial distribution of soil nutrients and plants in these systems, forming nutrient enriched 'resource islands,' under tree canopies. The purpose of this...
Resource Type:: Masters Thesis
Full Text:: Forest Resources Dean of the Graduate School I understand that my thesis will become

Spatial and age class analysis of managed western juniper (Juniperus occidentalis) woodlands in central Oregon

Creator:: Zophy, Kelley T.
Abstract:: Juniper is a native species to Oregon and confers ecological benefits to wildlife when it is at savannah and transitional densities. Its range and extent have fluctuated with climatic change, but the current range expansion is unprecedented in its extent. The range expansion has been associated with the degradation of...
Resource Type:: Masters Thesis
Full Text:: Forest Resources Department Dean of the Graduate School I understand that my thesis

Search Constraints

Search Results

Limit your search