Index Catalog // ScholarsArchive@OSU

Population biology of rare mariposa lilies (Calochortus: Liliaceae) endemic to serpentine soils in southwestern Oregon

Creator:: Fredricks, Nancy Ann
Abstract:: Population dynamics, plant communities, and abiotic environments of three narrowly endemic, allopatric mariposa lilies (Calochortus Pursh) are described and compared. All were restricted to ultramafic soils in southwestern Oregon with high concentrations of nickel, zinc, and chromium, and low calcium to magnesium ratios. Soils inhabited by the three species differed...
Resource Type:: Dissertation

Response of Artemisia tridentata ssp. wyomingensis and Stipa thurberiana to nitrogen amendments

Creator:: Wang, Chien-kuo
Abstract:: The effect of nitrogen on influencing the competitive balance between a shrub, Artemisia tridentata ssp. wyolningensis (ARTRW) and a perennial grass Stipa thurberiana (STTH) in a sagebrush steppe community was determined. Nitrogen levels were altered on 5x5 in plots by applying 4.5 gun2 of nitrogen in the form of ammonium...
Resource Type:: Masters Thesis

The Biology and ecology of weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia nuttalliana)

Creator:: Tarasoff, Catherine
Abstract:: Weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia nuttalliana) infest Kentucky bluegrass seed fields of eastern Oregon. Weeping alkaligrass is an introduced species from Eurasia, whereas Nuttall’s alkaligrass is native to semi arid environments of western North America. These species are often referred to collectively as ‘alkaligrass’; however, for farmers...
Resource Type:: Dissertation
Full Text:: Oregon State University Extension Service in 20001. Preliminary field visits and plant identification

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:: plant of rangelands in Oregon since its arrival in the early 20th century. In 2001, the Oregon

Understory vegetation response and nitrogen cycling following cutting of western juniper

Creator:: Bates, Jonathan D.
Abstract:: Since the late 1880's western juniper has expanded in range and increased in density in sagebrush-bunchgrass, riparian, and forested plant communities of the Pacific Northwest. Succession to western juniper woodland has been shown to reduce the productivity and diversity of the understory component, result in concentration of soil nutrients beneath...
Resource Type:: Dissertation
Full Text:: density in sagebrush-bunchgrass, riparian, and forested plant communities of the Pacific Northwest

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:: . Title: Role of Propagule Pressure and Priority Effects on Plant Establishment during Restoration of

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:: seeded to crested wheatgrass in southeastern Oregon. Plant community composition of crested

Geographic variation in distribution and cover of principle native and non-native plant species along gradients of topography, climate, and disturbance in protected-area sagebrush steppe communities of the Columbia Plateau

Creator:: Esposito, Daniel M.
Abstract:: The sagebrush steppe ecosystem of the Columbia Plateau has become degraded by a long history of alternative land use and associated perturbations. Protection of remnant stands of intact sagebrush steppe currently relies upon their preservation within the nation's network of parks and protected-areas. The John Day Fossil Beds National Monument,...
Resource Type:: Masters Thesis
Full Text:: , 2014. Title: Geographic Variation in Distribution and Cover of Principle Native and Non-native Plant

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:: ) Woodlands in central Oregon. Abstract approved:______________________________________________________

ScholarsArchive@OSU

Population biology of rare mariposa lilies (Calochortus: Liliaceae) endemic to serpentine soils in southwestern Oregon

Response of Artemisia tridentata ssp. wyomingensis and Stipa thurberiana to nitrogen amendments

The Biology and ecology of weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia nuttalliana)

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

Understory vegetation response and nitrogen cycling following cutting of western juniper

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

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

Geographic variation in distribution and cover of principle native and non-native plant species along gradients of topography, climate, and disturbance in protected-area sagebrush steppe communities of the Columbia Plateau

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

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