A study was undertaken in the Willamette Valley, Oregon, to document
1971 land use patterns as well as land use change in a smaller study
area in the 16 years prior, and to relate these to soil characteristics.
Quantification of these inter-relationships was aided by use of computer
tabulation and...
Published March 1937. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less...
The primary goal of this research was to identify the impacts that individual agricultural land uses have on fish communities in small streams located in the Willamette Valley of western Oregon. The diverse nature of the land use features of the valley provided a challenging but useful system for the...
Hydrologic processes within mineral flat wetlands, along with their
connections to groundwater and downstream surface water in lowland agricultural
catchments are poorly understood, particularly under different land uses. In the three
field studies included in this thesis, we examined infiltration, wetland hydroperiod,
groundwater recharge dynamics, surface runoff generation, and water...
A growing body of literature exists on how human population growth and changes in climatic factors influence the availability of water (Elliot et al. 2014, Prudhomme et al. 2014). These studies typically conclude that climate change is expected to have negative consequences on water availability, an effect that is magnified...
Despite holding substantial ecological value, wetlands in the United States have experienced a significant decline in both area and function over the past century with the majority of freshwater wetland loss attributed to agricultural conversion. Agriculture is the second largest industry in the State of Oregon and the State places...
Published June 1942. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Aggregate, which consists of crushed rock, sand, and gravel resources, is one of the most extracted resources in Oregon. Floodplain sites throughout the Willamette Valley -- particularly along the Willamette River -- are of particular importance because they produce high quality sand and gravel, located close to the aggregate market....
This research consists of two related yet distinct
studies: an observational study of the surface character of
the penetration of marine air into the southern Willamette
Valley and a climatological study of the summertime air
masses of northwestern Oregon.
For the observational study, temperature and estimated
wind data were gathered...
Chewings fescue [Festuca rubra L. subsp. fallax (Thuill.) Nyman] is a desired turfgrass with dense sod forming capabilities and superior shade tolerance. Thermal residue management (open-field burning) has traditionally been used to remove post-harvest residue and maintain seed yield over the life of the stand. However, alternative non-thermal residue management...
A field study on grass field burning was conducted in the
Willamette Valley of Oregon during the summer of 1965. Approximately 243,000 acres of grass fields are burned in the valley during
August and September. Serious air pollution problems result from
this burning. The purposes of the study were to...
Total organic carbon, total nitrogen, microbial respiration and enzyme
activity (β-glucosidase) were measured on several horizons of a Dayton silt loam
(fine, montmorillonitic, mesic, Typic Albaqualf) soil cropped to annual ryegrass
under two straw residue management systems. The study evaluated the effects
of annual burning of straw residues or annual...
Open-field burning has been an effective, economical, and widespread method of post-harvest residue management in creeping red fescue seed production in the Willamette Valley since the late 1940s. However, the use of field burning has been legislatively restricted due to air quality and safety issues. The foliar-applied plant growth regulator...
The Willamette River and its floodplain in northwest Oregon have changed dramatically since European settlement. At one time, the river was a vast complex system of braided channels with a broad floodplain forest; it has now been simplified by channelization and dams, and the forest has been removed to support...
Reservoir systems in the western US are managed to serve two main competing purposes: to reduce flooding during the winter and spring, and to provide water supply for multiple uses during the summer. Because the storage capacity of a reservoir cannot be used for both flood damage reduction and water...
Published April 1989. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Land use alters the physical and biological structure of stream ecosystems and potentially alters their capacity to process nitrogen (N), an essential nutrient that has nearly doubled in abundance on the biosphere
during the past century from human activities. In this dissertation, I quantified uptake and transformation of nitrate (NO₃⁻)...