This thesis merges the fields of Ecology and Anthropology by applying Habitat Suitability Modeling to the relationship between people and plants in the Pacific Northwest. In it, I create and optimize two Maxent habitat suitability models for camas (Camassia spp.) in Oregon. The first model describes the physical environment of...
Forest communities in the central portion of Oregon's western Cascades are arrayed along moisture and temperature gradients. With the aid of reconnaissance data and a computerized ordination technique, 23 forest communities have been provisionally recognized in two distinct forest zones, the Tsuga heterophylla (300 to 1050 m in elevation) and...
State-and-transition models (STMs) have been successfully used to
describe ecological dynamics in woodlands, shrublands, grasslands, and several other ecosystems. Changes in vegetation and soil are measured to gauge and predict plant community dynamics within ecological states and transitions between alternative ecological states. Ecological states and their boundaries are defined by...
Dalmatian toadflax (Linaria dalmatica) has become a prolific invasive plant of rangelands in Oregon since its arrival in the early 20th century. In 2001, the Oregon Department of Agriculture initiated a release program promoting the distribution of the stem-boring weevil, Mecinus janthinus as classical biological control agent to reduce densities...
Purposeful introductions of exotic species for rehabilitation efforts following wildfire are common on rangelands in the western U.S., though potential ecological impacts of introduced species in novel environments are often poorly understood. One such introduced species, Kochia prostrata (L.) Schrad (forage kochia) has been seeded on over 200,000 ha throughout...
Relatively recent increases in ponderosa pine abundance have effected unprecedented changes to ecosystem structure and function. Efforts to restore ponderosa pine systems are often focused on the manipulation of tree structure and the re-introduction of a more natural fire regime. Successful restoration should also incorporate understory components but information addressing...
The diverse lichen flora of the Pacific Northwest is being impacted by
population growth and by forest management practices. Accumulating information
about our lichen flora will improve our conservation strategies. This dissertation first
collects information to improve our understanding of how lichen communities vary
among forests of differing structure, and...
The West Eugene Wetlands, Eugene, Oregon, which provide habitat for number of endemic and endangered plant species, are currently threatened by a Reed canarygrass (Phalaris arundinacea L.) invasion. This study addresses the hypothesis that Phalaris spread can be explained in part by using watershed-scale landuse patterns as surrogates of the...