Spotted knapweed, Centaurea maculosa Lam. (Compositae) is an extremely
successful introduced weed species in the northwestern United States. Multiple factors
may be responsible for its success, including chemical defense. Two different types of
putative chemical defense agents are the focus of this thesis. The first is a bitter-tasting
sesquiterpene lactone,...
The purpose of this dissertation is to investigate Oregon public high school history teacher perspectives concerning standards-based reform initiatives springing from the No Child Left Behind legislation. The central question addressed in this study is: At what level has Standards-Based Education reform initiatives impacted Oregon high school history instruction and...
Diseased and healthy Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were identified at two black-stain root disease centers, caused by Leptographium wageneri var. pseudotsugae Harrington & Cobb, in the Oregon Coast Range near Coos Bay. Phloem and sapwood near the root collar were sampled monthly for 1 year, whereas roots were sampled...
Polynuclear aromatic hydrocarbons (PNAH) classified as noncarcinogens
may be photooxidized to mutagenic or toxic products by
near-ultraviolet (NUV) wavelengths of sunlight (290-320 nm). The
possibility that this represents a major degredation pathway in the
aquatic environment is of increasing concern. Large quantities of
PNAH from accidental oil spills, anthropogenic and...
Since the early 1950's, the distribution of sediment at the
mouth of Redwood Creek has been altered by the effects of channel
aggradation and channelization along the lower reach. Severe flooding
in 1953, 1955, and 1964 caused bank erosion, landsliding, and
channel geometry changes along Redwood Creek. The increased sediment...
Phellinus sulphurascens (previously the Douglas-fir form of Phellinus weirii) is an important native pathogen causing laminated root rot in forests of western North America. Visual crown symptoms, or attacks by bark or ambrosia beetles appear only during advanced stages of the disease with extensive infection in the lower bole. Ethanol...
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trees and for beetle host selection
RickG. Kelsey*, Gladwin Joseph, Doug Westlind, and Walter