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...
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...
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
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...
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....