Most studies of plant disease epidemiology have focused on epidemics in host
populations composed of a single genotype. But crop plant diversity can be a useful
means of improving the deployment of resistance genes. In a series of experiments with wheat stripe rust and potato late blight, we studied factors...
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...
A gene-ecological transplant study was made on populations of
the Crepis nana and C. elegans complex from the Arctic and Alpine of
North America. Transplants were collected from the Brooks Range,
Eagle Summit, and Alaska Range in Alaska, the Rocky Mountains in
Alberta, the Olympic Mountains in Washington, the Wallowa...
This dataset consists of native and exotic plant species metrics, including cover, richness, relative abundance and responses to the exclusion of wild ungulates and herbivory. The data were used for the manuscript: "Synergistic effects of wild ungulates and management intensification suppress native plants and promote exotics", published in the journal...
Three different ground cover management strategies were compared at the OSU research vineyard near Alpine, Oregon. Botanical diversity was actively increased in two diverse treatments. Another treatment was botanically uniform and contained creeping bentgrass (Agrostis stolonifera). The composition of the vineyard floor vegetation and grapevine performance as affected by the...
Vegetation diversity in the Wyoming big sagebrush/Thurber needlegrass (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young/Achnatherum thurberianum (Piper) Barkworth. syn. Stipa thurberiana Piper) plant association was studied across a condition class gradient in southeastern Oregon. All observable vascular plant species were counted during 6 seasons and 2 years and diversity...
In the tropics, widespread deforestation and conversion of primary forests to agricultural and pasture lands has resulted in losses of composition, structure, and functions of forest landscapes. Deforestation in the tropics is typically preformed via slash-and-burn practices; the byproducts from combustion have been identified as the second-highest form of anthropogenically...
The hump-shaped relationship that predicts highest species richness (species/unit area) at intermediate levels of productivity was examined for woody plants across the Pacific and Inland Northwest of the U.S. Many studies have examined this relationship at regional scales, but commonly use species range maps and surrogate measures of productivity (e.g....
In the Oregon Cascade Range, conifer encroachment has reduced the extent of mountain meadows by as much as 50% since the mid-1940s. Although encroachment results in a general decline of meadow species abundance and diversity, species differ in their sensitivities to encroachment: some show rapid declines whereas others persist in...
Expansion of Juniperus occidentalis into the sagebrush steppe has resulted in significant changes in understory composition. A consequence of increased J. occidentalis dominance may be a depletion of the seed bank. The potential for depletion is problematic because a reduction in the amount of species available from the seed bank...
