The impact that pesticides may have had on the mortality rates and productivity rates of non-game birds during the last 25 years was evaluated by studying the population dynamics of 16 species. A mathematical model showing the relationships between population parameters that yielded stable populations was developed. The information needed...
Food habits and levels of organochlorine compounds, lead, and mercury in resident and wintering bald eagles were studied in southcentral Oregon and California, 1979-83. Food habits were assessed by examination of castings from winter communal roosts, identification of 2938 prey items found at nest sites and foraging areas, and observations...
Approximately 200 raw prunes were harvested from each of five Italian prune trees near Corvallis every three days for nine consecutive harvest dates. Forty individual fruit from each tree were drawn at random and subjected to a series of fresh fruit quality tests.
For each quality factor which was measured,...
Shear wave attenuation measurements were made
using ceramic bimorph transducers to excite transverse
vibrations in a cylindrical column of unconsolidated
sediment. Three different water-saturated
sediments were used in an attempt to determine the
effects of grain shape and sorting on the frequency
dependence of attenuation. The mean grain size of...
Chipping varieties and model systems were used to determine the role of potato
constituents on chip color. Composition was evaluated by HPLC and chip color
measured using a ColorQuest colorimeter. Reducing sugar (RS) content did not
completely explain color quality when present in low concentrations (<60 mg/lOOg).
Levels of ascorbic...
This study was directed to improve our understanding of the ecology of Swiss needle cast (SNC) of Douglas-fir, a disease that produces extensive damage to forests and plantation in the coastal region of Oregon and Washington. A disease prediction model for the coastal area of Oregon was built by establishing...
Accurate taxonomy is essential to preservation and management of native
grasses. Four problems in fescue taxonomy were investigated: the identity of the
native fescue that dominates western Oregon and Washington prairies, the relationship
of native Festuca roemeri to closely related grasses, the status of F. howellii and F.
washingtonica, and...
The effects of late spring defoliation on the winter forage quality of bluebunch wheatgrass
(Agropyron spicatum [Pursh] Scribn. & Smith), Idaho fescue (Festuca idahoensis Elmer) and elk sedge
(Carex geyeri Boott) and the response of wintering Rocky Mountain elk (Cervus elaphus nelsoni Bailey) to
changes in winter range forage quality...