Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare.
Consequently, long-term effects of fire on soils are often hypothesized from
short-term effects. In a chronosequence study, I studied 24 western Cascades
(Oregon) forest stands thought to...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
Radiotelemetry was used to study the seasonal movements and habitat use of adult westslope cutthroat trout Oncorhynchus clarki lewisi in Roberts
Creek and Rail Creek, headwater tributaries of the John Day River, Oregon,
from September 2000 to December 2001. The objectives were to (1)
describe adult cutthroat trout life history...
This thesis focuses on the application of the cosmogenic nuclide Beryllium-10 (10Be) in an effort to better constrain the thickness history of the Fennoscandian Ice Sheet (FIS) at the Last Glacial Maximum (LGM) and into the Holocene, as well as begin to answer the long-standing question regarding the age
and...
Myxobacteria represent an interesting class of Gram-negative soil bacteria. These bacteria utilize organic materials from the environment as a food source by the action of their extracellular hydrolytic enzymes. They grow vegetatively in the presence of adequate nutrients. During starvation conditions, however, they aggregate and form multicellular structures called fruiting...
Tree species directly and indirectly affect soil nutrient cycles. I sought to characterize soils and foliage associated with four common canopy tree species (Douglas-fir, western hemlock, western redcedar, and bigleaf maple) in mixed-species old-growth forests of the Oregon Coast Range and to determine whether and how soils differ among the...
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Steven S. Perakis
Tree species directly and indirectly affect soil nutrient cycles. I
The Mixteco primarily reside in the Mexican State of Oaxaca in Southwestern Mexico. They have been arriving in larger numbers then ever before to this part of the North American continent in the last twenty years.Their experience is composed of different dynamics compared to those of their mainstream Mexican counterpart....
Salmon restoration has become a major priority in the Pacific Northwest. In the State of Oregon, much of
the responsibility for habitat restoration has fallen on local watershed councils, with the majority of their
funding coming from state and federal grants. Funding limitations, including the amount of funds allotted
to...
The hemlock woolly adelgid, Adelges tsugae, is causing widespread mortality of eastern hemlock, Tsuga canadensis, in the eastern United States. In the West, A. tsugae causes negligible damage to western hemlock, Tsuga heterophylla. Host tolerance traits and presence of endemic predators may be contributing to the relative tolerance of western...
This thesis examines the impact of urban renewal on individual health, specifically focusing on an urban planning model called Smart Growth that is being used in Portland, Oregon. Findings are based on qualitative and quantitative analyses of interview and survey data from study participants living in a community where renewal...