A cultural landscape analysis of two historic cemeteries in St. Paul, Oregon demonstrates that the residents of this early community were unknowingly using grave markers to express their worldview and the identities that they felt were most important. Because of the historical and cultural development of this community as the...
Post-settlement juniper expansion in the western states has been reported for decades,
including western juniper (Juniperus occidentalis Hook ssp. occidentalis) woodlands in the northwestern states. A 15 km2 study area in the Sheep Rock Unit of John Day Fossil Beds National Monument in eastern Oregon was selected to study spatial...
I studied small-mammal communities and their response to grazing in mixed-conifer forests and oak woodlands in the Cascade-Siskiyou National Monument in southern Oregon. My objectives were to (1) compare small-mammal communities among forest types and grazing intensities, (2) identify riparian affiliated species, and (3) describe microhabitat associations. Over two years,...
The historical function of fire in sagebrush steppe has been altered by 19th century overgrazing, active fire suppression, annual grass invasion and encroachment of woody species. The significance of fire to these systems is known, but research on long-term fire effects are limited. The Sheep Rock management unit of the...
This dissertation presents the results of three studies that assessed climate variability on short and long timescales in western United States. The growth of carbonate formations in caves (speleothems) is used to infer the timing and amplitude of past climate variability. We first assess the controls on speleothem growth for...
Pygmy rabbits (Brachylagus idahoensis) in Oregon and Washington are a sagebrush (Artemisia tridentata spp.) obligate species of concern because of declining populations and extirpation from much of their range. Efforts are underway to establish a captive bred population of the Columbia Basin pygmy rabbit in Washington state for reintroduction into...
The sagebrush steppe ecosystem of the Columbia Plateau has become degraded by a long history of alternative land use and associated perturbations. Protection of remnant stands of intact sagebrush steppe currently relies upon their preservation within the nation's network of parks and protected-areas. The John Day Fossil Beds National Monument,...