The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, snow covered area, and earlier spring snowmelt are documented trends that are projected to continue into the future. With an...
The local presence or absence of individual botanical species can be predicted with high accuracy by a simple feed-forward neural network, using only local climate data to make inference. This study proposes a framework for learning these predictive models, demonstrates highly accurate predictions for species with a sufficiently large area...
The purpose of this dissertation was to define macrolichen community gradients in relation to succession, grazing and the environment. First, species scores indicating when macrolichen species appeared following disturbance were derived from the literature. Weighted averaging of these data with a community matrix created a successional score for each sample...
Hunter-gatherers depend on naturally occurring resources and, in order to survive, must overcome resource procurement challenges inherent in their environment. One challenge relates to the temporal and spatial availability of resources, which hunter-gatherers address, in part, through the strategic use of space to position themselves for optimal access to necessary...
Despite holding substantial ecological value, wetlands in the United States have experienced a significant decline in both area and function over the past century with the majority of freshwater wetland loss attributed to agricultural conversion. Agriculture is the second largest industry in the State of Oregon and the State places...
This dissertation focuses on the evolutionary forces of genetic drift and gene flow in frog populations. The balance of these two forces and the force of mutation largely determine the amount of neutral genetic variation within populations as well as the degree of genetic similarity among populations. The stochastic evolutionary...
An integrative method for monitoring glacier geometry change and mass balance is presented and applied to the Pacific Northwest, USA. Acting as a baseline for interpretation of future changes in glacier size and shape, we first derive a new inventory of regional glacier cover using remotely sensed data. To investigate...
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...
In 1994, with the approval of the Northwest Forest Plan, the livelihood of individuals in the surrounding communities of the Siuslaw National Forest and Siuslaw Watershed were further impacted by already diminished traditional timber practices. In 2003, the United States Forest Service developed an innovative program, stewardship contracting, aimed at...
Relative to other systems in the PNW, the rain-dominated, coastal watersheds of western Oregon have shallow aquifers. Given the seasonality of streamflow and storage limitations in coastal, rain-dominated watersheds, changes in the temporal patterns of precipitation have the potential to magnify the risk of extreme streamflow conditions during both high-...