The release of marine debris into the oceans and seas is a global issue of growing concern. These materials are harmful to marine environments and can also transport non-native species to novel habitats. Non-native species floating on marine litter is one of the lesser known impacts associated with marine debris....
For tuberizing crops like potato (Solanum tuberosum), the geocaulosphere, or the zone of soil in contact with and influenced by the tuber, is a distinct sphere of microbial life and represents an important interface between the potato crop and the soil environment. Upon potato harvest, specific geocaulosphere soil called tare...
The influence of loss of diversity on community dynamics and ecosystem functioning has recently received considerable attention. Although study of biodiversity has a long history within ecology, empirical investigations exploring consequences of loss have been rare. Because many factors confound diversity comparisons, experimental manipulations of diversity offer the most direct...
The European hazelnut, Corylus avellana L., was imported into the U.S. in the late 1800's and is now grown throughout the Willamette Valley in Oregon. A native species of hazelnut, C. cornuta Marshall, is a common shrub found in forested areas of the Pacific Northwest. Foliage of both C. avellana...
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...
Hardwood lumber is a major forest product, and board grading is an important part of its manufacturing and marketing. Computer grading programs have been used to train graders and to grade lumber for board data banks, but they have not been used to machine-grade boards in an industrial environment because...
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...
This thesis provides the first general description of the natural variation in age
structure, growth rates, and survival in headwater populations of coastal cutthroat
trout Oncorhynchus clarkii clarkii from western Oregon, and a subsequent
synthesis of these life-history characteristics across the range of the subspecies.
Age, growth, and survival were...
Biological invasions threaten native biodiversity, alter ecosystem function, and are a major cause of economic losses across the planet. The most impactful invaders alter disturbance regimes and initiate state shifts to outside the historical range of variability of the ecosystem. Concern for ecological and economic losses has prompted a rapid...