In many areas of the Western U.S., diffuse knapweed (Centaurea diffusa Lam.)
has invaded into plant communities dominated by bluebunch wheatgrass
(Pseudomegnaria spicata [Pursh] A. Love). The objectives of this study were to compare
growth response of both species when grown under altered moisture and temperature
regimes while in the...
Ranchers and resource managers have become concerned about the
role and spread of Cardaria draba (L.) Desv. (whitetop) in the sagebrush
steppe of Northeastern Oregon. This area is an important natural resource
for livestock production and big game winter range.
An area near Keating, Oregon was selected to study the...
Cheatgrass (Bromus tectorum L.) and yellow starthistle (Centaurea
soistitialis L.) have invaded over 3 million ha of grasslands in the western U.S.
Future management will require an understanding of the conditions,
mechanisms, and processes which control species dominance, community
dynamics, and desirable plant establishment in these alien dominated annual
rangelands....
A method has been developed for the continuous automated monitoring
of cardiac output in adult rainbow trout. Average cardiac output measured under
control conditions and varied environmental conditions of hypoxia and post-hypoxia
was significantly higher (P≤ 0.05) in male than female trout. The cardiac
output of trout in spawning condition...
Forest soils with low bulk densities are often considered less
susceptible to compaction than soils with higher bulk densities. The
objective of this study was to determine if soil strength controlled the
compression of soils with low bulk density. Four soils were selected
for this evaluation. Three of these were...
The use of efficient basis functions to model and represent flows with
internal sharp velocity gradients, such as shocks or eddy microfronts, are
investigated. This is achieved by analysing artificial data, observed atmospheric
turbulence data and by the use of a Burgers' equation based spectral
model. The concept of an...
Human activities may contribute to the eutrophication of surface waters by
providing nutrients to aquatic ecosystems. Phosphorus is frequently identified as a
nutrient that is limiting to most aquatic ecosystems under natural conditions. Sources of
phosphorus contributing to eutrophic conditions often include nonpoint sources that are
dispersed across the landscape....
Yellow starthistle (Centaurea solstitialis L.) is a member of the knapweed
(Centaurea L.) complex. It is poor forage for all livestock and causes
“chewing disease,” a nervous disorder, in horses. Yellow starthistle infests
millions of acres in California and the Pacific Northwest. Infestations range
from scattered plants to dense stands...
Keywords: Steve Strauss, Rick Strachan, Starker Forests, Wheeler Wood Composites Laboratory, Barbara Middleton, Joan Davies, Lisa Mattes, Larry Chapman, Iwan Ho, Jim WIlson, John Sessions, Brian Kramer, Mike Newton, Faye Stewart, Norma Erickson, Paul Adams, Gordan A. and Priscilla E. Duncan, Jim Trappe, Corey Arentz, Wang Zheng-Qi, Loran L. ("Stub")...
The effect of frozen storage time on the composition
of the cell wall polysaccharide (CWP) of muskmelon (Cucumis
melo) cultivars at different stages of maturity was investigated.
Changes in composition, firmness, drip loss, and
color of Cantaloupe and Honey Dew melon flesh were determined
at three stages of maturity and...
The availability of new pear rootstocks could be increased by development of an efficient micropropagation system. Many P. calleryana, P. betulifolia and P. communis rootstocks are resistant to many pear diseases and are graft compatible with leading cultivars. Explains of three potentially useful rootstock selections P. calleryana Decne 'OPR 157',...
Agricultural production in the Sahelian region of Africa is
among the lowest in the world. Cyclical infestations of locusts and
grasshoppers have contributed to this low productivity. The infestations
appear to be triggered by heavy rainfall at the beginning of a crop season
after extended drought. Because locusts and grasshoppers...
In animals, reproductive behaviors serve to attract individuals together during the
breeding season and to coordinate the behavioral and physiological states of individuals
so that mating can successfully occur. In snakes, the various reproductive behaviors
including courtship, mating, courtship inhibition, male combat and trailing are mediated
primarily by pheromones. Pheromones...
This thesis research is a series of five studies dealing
with various aspects of hazelnut quality:
1. Identification of kernel mold and its incidence among
hazelnut varieties.
2. Seasonal development and composition of kernels.
3. Hazelnut oil composition (fatty acids and
tocopherols) of seventeen varieties.
4. Hazelnut oil composition compared...
California brome (Bromus carinatus Hook & Arn), is
considered an important weed infesting wheat and grass seed
fields in the Willamette Valley of Oregon. Field and
greenhouse experiments were conducted to study some
biological aspects to develop more efficient management
strategies.
A field experiment was conducted to determine the
effect...
The encroachment of alien weeds onto western rangelands is one of the most perilous and perhaps least recognized problems facing land managers today. Oregon rangelands are under siege from ever-increasing numbers and distribution of exotic weeds. They threaten Oregon's economy and environmental quality by reducing livestock forage, wildlife habitat, watershed...
Published June 1991. 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
Feral goat (Capra hircus) populations adversely impact native insular biota and physical habitats worldwide. The effectiveness of the Judas goat technique for eradicating remnant feral goats was studied on San Clemente Island (SCI), California from June 1989 through April 1991. By April 1991, 263 feral goats were killed on SCI;...
Linear alkylbenzenesulfonate (LAS) is the most widely used anionic surfactant in
commercial detergent formulations. The environmental fate of LAS is of interest because
of its disposal to wastewater treatment facilities and subsequent occurrence as a
micropollutant in surface waters and groundwater. While LAS fate in wastewater
treatment systems and surface...
Published June 1994. 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
Published September 1995. 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
Research studies indicated that differences in cognitive
processing style influence individual behavior on various types of
tasks. This study investigated the effect of the cognitive style
dimension, field independence-dependence, on the metacognitive
functioning of individuals involved in three problem tasks which
varied in inherent structure.
Twenty-six subjects were randomly selected...
The agriculture production system in the post-war United States is characterized
as highly specialized and increasingly dependent on off-farm inputs. Although the US
has traditionally supported agriculture with numerous government commodity programs
such as target prices, nonrecourse loans, and deficiency payments, agriculture today is
perceived as one of the major...
Thesis research focused on: 1) Water and fertilizer gradients
within the plant root zone, and effects of chemical and physical
gradients on Trichoderma harzianum populations. 2) Regulation of root
growth physically with permeable fabric containers and chemically with
copper compounds. 3) Effects of copper coatings for fabric containers
on Glomus...
This research questions the effectiveness of newspapers as a
vehicle of environmental information by determining whether the
public attitude in Alaska towards off-shore oil exploration was
consistent with that expressed in the local newspapers. All
newspaper articles about off-shore oil exploration published in
Alaska between 1980 and May 1987 were...
The grain milling industry has undergone substantial change during the past several decades in technical as well as industry structure. This study seeks to determine how industry performance, as reflected in productivity growth, has varied since the 1950's. Productivity growth is represented primarily by its dual rate, the percentage reduction...
This is a bibliography of doctoral dissertations and masters' theses in forestry and related topics issued during the period from July 1981 through June 1990. The colleges and universities included are all accredited by the Society of American Foresters. The actual listings were supplied by the individual institutions. Topics covered...
Sound wetland management depends on an accurate comprehensive
assessment of functional wetland values. This management should account
for the cumulative impacts to regions and landscapes resulting from
piecemeal destruction and degradation of wetland resources. A regional or
watershed evaluation of wetland values can also make site-specific
assessments more efficient. The...