Quaking aspen (Populus tremuloides) is an important tree species in the western United States and there has been much concern about its persistence. In this thesis, I report on aspen in a portion of its range that has not been previously evaluated: the eastern and western slopes of the Central...
Members of the family Sciomyzidae, known as snail-killing or marsh flies, are unique amongst insects in that the vast majority of reared species feed exclusively on mollusks and as a result their biological control potential has been well documented in the scientific literature. However, in North America there is a...
An ASR metric and site rating index applied to over 120 municipal and agricultural locations across Oregon, combined with comparison to case study data from existing ASR sites, indicate that more than 50% of selected sites are hydrogeologically suitable for ASR. The ASR metric is a ratio of aquifer storage...
The assessment of habitat quality for wild populations requires evaluation of vital rates associated with the use of that habitat. Factors associated with bottom-up (forage) or top-down (predation) regulation and the relative contribution of these processes on ungulate populations are difficult to quantify, especially for a cryptic, but widely distributed...
Five genotypes from California (Ventana, Caniarosa, San Miguel, 13G97, and Venice) and Oregon (Totem, Puget Reliance, Puget Summer, Hood and Independence) were evaluated for quality. The volatile compounds were analyzed using head space solid phase micro extraction-gas chromatography-flame ionization detection (GGFID) and gas chromatography-mass spectrometry (GC-MS). Odor activity values of...
Reconciling working landscapes with Endangered Species Act (ESA) requirements is a vexing challenge playing out in watersheds across the western United States. Beaver-related watershed restoration (BRR) methodologies have the potential to reconcile competing demands for resource extraction and recovery of ESA-listed species by restoring ecosystem functionality more effectively and at...
Commercial fisheries are coupled human-natural systems that cross state borders and integrate private, public, academic sectors and interests. These systems integrate complicated relationships between coastal socioeconomics, resource management and environmental realms. Previous findings from West Coast-based studies have identified aging trends in commercial fisheries participation, commonly referred to as the...
Soil is a complex living system with high heterogeneity, which makes locating soil map boundaries a challenge. In traditional soil survey, the placement of soil map boundaries relies largely (at least initially) on identifying the soil-forming factors of biota and topographic relief through stereo aerial photo pairs. Future soil survey...