Seed size, abundance, viability, dormancy, and germination requirements strongly influence plant establishment and therefore are important considerations in restoration of native vegetation. These characteristics provide criteria for selection of suitable species, development of collection and pretreatment methods, and determination of seeding densities. The first set of objectives of this study...
Erigeron decumbens var. decumbens, the Willamette daisy, is known only from the Willamette Valley of Oregon. Herbarium records, from the 1800's until 1934, indicate that the Willamette daisy was once common and widely distributed throughout the Willamette Valley (Clark et al. 1993). However, between 1934 and 1980, this taxon was...
One goal of this environmental education curriculum is that students will gain an appreciation of Willamette Valley wetland prairies, a threatened ecosystem, and will gain an understanding of the importance of protecting these wetlands. A second goal is that students will see first-hand the processes involved in conducting scientific field...
The status of wild sheep in North America typifies the plight of many wildlife species in modern times: wild sheep have declined to 10-40% of their numbers during pristine times and on a global scale approximately 31% of Caprine are considered threatened or critical. As human populations and the number...
This thesis discusses both theoretical and practical considerations inherent in conducting community-based research within a case study of sea turtle conservation in Baja California, Mexico. A brief background, including the general ecology, status and distribution of sea turtles of the Baja peninsula is presented, with an overview of the current...
A major goal of conservation biology is to elucidate the population genetic structure in threatened species and assess the relative importance of the evolutionary forces that shape that population genetic structure. I conducted three studies in the declining amphibian Rana cascadae to assess levels of population genetic differentiation and the...
This dissertation consists of three papers on the use of incentives for conservation of endangered species on private land. The first paper examines incentives based on providing landowners with assurances regarding future regulation in exchange for their participation in a conservation agreement. The second and third papers are empirical analyses...
The Humboldt marten, Martes americana humboldtensis, has undergone a dramatic decline throughout its historical distribution in coastal Northwestern California. There is currently only one known population occupying an area occurring in <5% of the historical distribution of the subspecies. Conservation and management efforts to benefit this population are hampered by...