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...
One second GPS collars were deployed on cattle in three different pastures at three separate times during the year. In each riparian pasture the vegetative communities and stream bank edge were digitally mapped using low elevation aerial photographs and checked in the field for accuracy. A 5 m buffer zone...
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....
Yellow starthistle (Centaurea solstitialis L.) is an introduced Asteraceae that has become established on 10 million acres in the Pacific Northwest and California. This weed functions as an annual or short-lived perennial and depends on seeds for reproduction. Strategies of control that reduce plant fitness or lower seed production or...
A case study examining the relationship between stream temperatures and the thermal environment through which streams flow was conducted on the headwaters of 4 tributaries of the Burnt River (Barney, Elk, Greenhorn, and Stevens Creeks) in northeastern Oregon during July through August 1998 and 1999. Barney Creek and Stevens Creek...
While it can be said that peer mentor-mentee relationships in college can lead to meaningful connections and interpersonal support, there is a lack of literature about how exactly mentor-relationship connections are made. This study examines the relationship building strategies that peer mentors used to connect with their mentees in the...
Two tributaries of the south fork of the Burnt River, near Unity Oregon were studied
during the summers of 2000 and 2001 to determine water heating and cooling
patterns. Hourly temperature data were recorded for air, water, and soil parameters
at four elevations 150m apart on Barney and Stevens Creeks....
Managing rangelands with livestock grazing is a tool that can be applied to obtain vegetation management objectives. Animals utilize available resources, which vary in quantity and quality, across the landscape. Their movements are adjusted to the spatial and temporal heterogeneity of resource distribution. Controlling livestock distribution is fundamental to economically...
The Long Tom Watershed Council (LTWC) is a non-profit organization in Eugene, Oregon that serves to protect and enhance watershed health in the Long Tom River Basin. The Amazon Creek Initiative was launched by the LTWC in 2011 as Oregon’s newest Pesticide Stewardship Partner. Goals of the initiative are to...
Research Objective: Nearly 60 million people in the United States reside in a rural area. Residents in rural areas have higher rates of chronic disease, risky health behaviors, disability, infant mortality, and age-adjusted mortality than their urban counterparts. Health insurance and access to care mitigate those risks, in part because...
A study was conducted of the influence of various climatic and
soil factors on the development of onion pink root disease and of the
influences of temperature, light, pH, carbon and nitrogen sources,
and vitamins on the growth in vitro of an Oregon isolate of the pink
root fungus, Pyrenochaeta...
The temporal relationships among selected correlates of
hepatocellular damage were investigated in cordotomized, hypothermic
rats intoxicated with carbon tetrachloride (CC1₄). Rats
were spinally transected between C6 and C7 and allowed to become
hypothermic. CC1₄ (1.25 ml/kg ip) was administered as a 1:1 solution
in corn oil. Plasma alanine aminotransferase (ALT)...
Ninety-six hour acute toxicity bioassays were employed to
determine the tolerance of juvenile coho salmon to chlorinated
stabilized kraft mill effluent (SKME). In addition the effect of
chlorinated SKME on the growth of juvenile coho salmon in six and
ten day experiments was studied.
Results of the acute toxicity tests...
Rats were given single i.p. injections of BCNU to
investigate changes in hepatic cytochrome P-450 content and
specific activity in male rats. Microsomal P-450 levels
were unchanged from 6 hours to 7 days after BCNU treatment
but by day 21 they had decreased 45%. Ethylmorphine N-demethylase
activity (nm product x...
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...
The objective of this study was to evaluate the influence of cow age on grazing distribution relative to mountain riparian areas. In each of two years, sixty cow-calf pairs were stratified by age into the following treatments: 1) thirty first calf heifers (442 kg, body condition score (BCS)=4.5), and 2)...
This study evaluated the influence of cattle stocking density on botanical composition of diet, diet preference, and cattle performance on the Zumwalt Prairie in Northeastern Oregon. In each of two years, 192 cow-calf pairs (549.27 kg, BCS = 4.89) and 48 yearling heifers (383.34 kg, BCS = 5.02) were stratified...
Cottonwood provides structural and functional benefits to riparian areas where it is adapted. Cottonwood is adapted to specific growing conditions. If you want to promote cottonwood establishment, it is important to understand its ecology, including site characteristics and conditions required for establishment and survival. This publication is not intended to...
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...
Petroleum mulch applied on the soil surface over a row of
planted seeds promotes a more rapid and a more uniform germination
of seeds, enhances elongation of seedlings and in some cases increases
the yield of the crop. The beneficial effects of petroleum
mulch have usually been attributed to increased...
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...
Rates of germination and emergence of corn were measured as
influenced by soil physical parameters using blotter paper and a sandy
loam soil as growth media. The corn seeds used were a hybrid of
Funk's (DJ7xLH93).
Experimental conditions were soil temperature of 20°C, 25°C,
30°C, and 35°C, soil water potential...
The effect of soil temperature and plant water stress on nitrogen
uptake, growth rate and transpiration rate of wheat (Triticum aestivum
VILL. , Host) seedlings was studied. A special apparatus for the control
of plant water stress and root temperature was used.
Leaf area was measured by the air flow...
Multiple use of waste heat from power plants may become an
important consideration in the development, siting, and certification
of these plants. A multiple use system of components that can
beneficially utilize waste heat may include home heating and cooling,
greenhouses, animal enclosures, open basins for single cell protein
production...
Global Positioning System (GPS) and Geographic Information System (GIS) technologies were employed to evaluate cattle occupancy of three landscape attributes on three different grazing allotments administered by the Wallowa Whitman National Forest in Northeast Oregon. Topographic characteristics of slope; 0-4%, 4-12%, 12-35% and >35% were evaluated as well as north...
Invasive plant species are expanding and transforming vegetative communities across Oregon and throughout the United States. Over the past three decades remote sensing, geographic information system (GIS), and Global Positioning System (GPS) technologies have been integrated to detect and map the distribution of noxious rangeland plants. This study developed low-cost...
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...
An experimental investigation has been made of the effect of
vibration on heat transfer from a cylinder in crossflow. The
cylinder used was 3/16-inch in diameter and was sinusoidally
oscillated in the vertical direction by a mechanical drive mechanism
while immersed in an open water channel. Nominal amplitude
ratios, a/d,...
Flood plain regulations are one of six major adjustments
used to cope with flood hazard in the United States. This adjustment
was essentially neglected in the national flood hazard policies
until Congress enacted the National Flood Insurance Act of 1968.
The implementation of regulations, as called for in the Act,...
This analysis is the study of Oregon's wildlife resources from
the period prior to white settlement up to the present time, including
critical projections, based on present trends and expected conditions
for both human and wildlife populations in the state up to the year 2010.
Prior to white settlement Oregon...
Published July 1988. 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
Productivity Interfirm Comparison (PIC) is a simple
method used to improve productivity at the firm level,
where a number of firms operate in the same product line so
that performance information on the firms can be compiled
and compared. This results in identifying potential areas
for improvement or exploitation. The...
A study was performed to assess the uptake and retention patterns
of cesium-134 in the gray-tailed vole, Microtus canicaudus Miller. To
furnish a realistic source of contaminated food for the voles, wheat
seedlings were raised in hydroponic solutions to provide radiocesium
labeled wheat clippings. The hydroponic system was designed to...
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")...
Over recent decades, the Bering Sea has experienced oceanic and atmospheric
climate extremes, including record warm ocean temperature anomalies and marine heatwaves (MHWs), and increasingly variable air-sea heat fluxes. In this work, we assess the relative roles of surface forcing and ocean dynamical processes on mixed layer temperature (MLT) tendency...
A living mulch system consists of growing a regulated cover crop
with an economic crop. Living mulches are often interplanted with
horticultural crops, but competition for water can adversely affect
crop production. Various management practices may limit the negative
effects.
Studies were conducted for two purposes: (1) to determine if...
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',...
The effects of five tillage treatments on soil bulk density and
mechanical impedance were examined on Newburg sandy loam soil in the
Willamette Valley, Oregon, in 1987. Subsequent effects on seedling
emergence and yield of carrots (Daucus carota L., cvs. Orlando Gold
and Royal Chantenay) were also measured. Mechanical impedance...
This study aims to improve knowledge of how suspended particulate matter (SPM) affects hydrophobic contaminant transport in the lower Columbia River and its estuary, using polycyclic aromatic hydrocarbons (PAHs) as model compounds. It is hypothesized that PAHs are transported to the estuarine turbidity maximum (ETM), a prime feeding zone in...
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...
Sensory evaluation and instrumental methods were applied to the
evaluation of strawberry juice concentrate (68°Brix) stored at
20°C which had been produced both commercially (C-SJC) and in a
pilot plant (SJC). Sensory evaluation included taste and aroma
ratings by intensity scaling and time-intensity of taste, and visual
colorimetry by matching...