The application of modern land management practices beginning at the turn of the 20th century is widely believed to have dramatically transformed forest landscapes of the inland Pacific Northwest. Restoring historical conditions to make forests resilient to future climate and disturbance regimes is a major goal of federal forest managers....
The influence of natural enemies and plant apparency in
determining the abundance of the cabbage aphid Brevicoryne brassicae L.
and the imported cabbageworm Pieris rapae L. was examined on collards
grown in a collard monoculture and in a collard-alfalfa biculture.
This design was used to examine the factors affecting collardherbivore...
The Thurstone-Mosteller and Bradley-Terry Models are commonly used to rank items from paired comparisons experiments in which one item in each pair "wins," and to assess the importance of time-independent explanatory variables on such rankings. The first part of this thesis clarifies the use of probit and logistic regression models...
Anadromous fish populations in the Pacific Northwest have
undergone substantial change throughout the past century.
Historical periods of over-harvest and the construction of
numerous dams throughout the region have contributed to declines
in the runs of naturally spawning stocks. Management efforts to
rebuild fish populations have focused on the restriction...
Commercial thinning operations can result in damage to residual stems. A literature review revealed that little was known about the effects of residual logging wounds with regard to rotation-age commercial conifers, particularly Douglas-fir. An experiment to examine fungal colonization of Douglas-fir following logging damage showed that while damage was significant...
The physico-chemical reactions of ammonia in soils and clays have many practical and theoretical implications. On the one hand, large quantities of anhydrous ammonia are used annually in agriculture for fertilizer; the dry gas is applied directly to the soil by simply injecting it below the ground surface. On the...