Publications
Filter Total Items: 2002
Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales
1. Spatial patterns in channel morphology and substratum composition at small (1–10 metres) and large scales (1–10 kilometres) were analysed to determine the influence of habitat heterogeneity on the distribution and abundance of larval lamprey.2. We used a nested sampling design and multiple logistic regression to evaluate spatial heterogeneity in the abundance of larval Pacific lamprey, Lampetra
Authors
Christian E. Torgersen, David A. Close
Use of radar remote sensing (RADARSAT) to map winter wetland habitat for shorebirds in an agricultural landscape
Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38° incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriif
Authors
Oriane W. Taft, Susan M. Haig, Chris Kiilsgaard
Asymmetrical effects of introduced Rana catesbeiana on native ranid frogs in Oregon, USA
Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. ca
Cervid forage utilization in noncommercially thinned ponderosa pine forests
To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22 to 32 m2/ha basal area), moderately thinned (12 to 22 m2/
Authors
M.C. Gibbs, J.A. Jenks, C.S. Deperno, B.F. Sowell, Kurt J. Jenkins
Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia
Tailed frog (Ascaphus truei Stejneger) populations are at risk in much of the Pacific Northwest, and recolonization of sites may be slow postlogging. To examine the terrestrial movements of Ascaphus in clearcuts and old growth, we employed pitfall traps and drift-fence arrays installed along streams and 100 m into upland habitat. In the fall, we captured frogs farther from streams in old growth th
Authors
Tanya R. Wahbe, Fred L. Bunnell, R. Bruce Bury
Geographic variation in social acceptability of wildland fuels management in the western United States
Contemporary natural resource management requires consideration of the social acceptability of management practices and conditions. Agencies wishing to measure, respond to, and influence social acceptability must understand the nuances of public perception regarding controversial issues. This study explores social acceptability judgments about one such issue: reduction of wildland fuel hazards on
Status of nesting ospreys in coastal Baja California, Sonora, and Sinaloa, Mexico, 1977 and 1992-1993
No abstract available.
Authors
Charles J. Henny, Daniel W. Anderson
Science for the changing Great Basin
The U.S. Geological Survey (USGS), with its multidisciplinary structure and role as a federal science organization, is well suited to provide integrated science in the Great Basin of the western United States. A research strategy developed by the USGS and collaborating partners addresses critical management issues in the basin, including invasive species, status and trends of wildlife populations
Authors
Erik Beever, David A. Pyke
Effects of invasive alien plants on fire regimes
Plant invasions are widely recognized as significant threats to biodiversity conservation worldwide. One way invasions can affect native ecosystems is by changing fuel properties, which can in turn affect fire behavior and, ultimately, alter fire regime characteristics such as frequency, intensity, extent, type, and seasonality of fire. If the regime changes subsequently promote the dominance of t
Authors
M.L. Brooks, C. M. D'Antonio, D.M. Richardson, J.M. DiTomaso, J.B. Grace, R.J. Hobbs, J. E. Keeley, M. Pellant, D. Pyke
Sagebrush ecosystems: current status and trends.
The sagebrush (Artemisia spp.) biome has changed since settlement by Europeans. The current distribution, composition and dynamics, and disturbance regimes of sagebrush ecosystems have been altered by interactions among disturbance, land use, and invasion of exotic plants. In this chapter, we present the dominant factors that have influenced habitats across the sagebrush biome. Using a large-scale
Authors
E.A. Beever, J.W. Connelly, S.T. Knick, M.A. Schroeder, S. J. Stiver
Vital signs monitoring plan for the Klamath Network: Phase I report
This report chronicles the Phase 1 stage of the vital signs monitoring program for the Klamath Network. It consists of two chapters and eleven appendixes. The purposes of Chapter One are to 1) describe the network administrative structure and approach to planning; 2) introduce the Klamath Network parks, their resources, and environmental settings; 3) explain the need for monitoring changes in reso
Authors
Daniel Sarr, Dennis Odion, Robert E. Truitt, Erik A. Beever, Sarah Shafer, Andrew Duff, Sean B. Smith, Windy Bunn, Judy Rocchio, Eli Sarnat, John Alexander, Steve Jessup
Pattern detection in stream networks: Quantifying spatial variability in fish distribution
Biological and physical properties of rivers and streams are inherently difficult to sample and visualize at the resolution and extent necessary to detect fine-scale distributional patterns over large areas. Satellite imagery and broad-scale fish survey methods are effective for quantifying spatial variability in biological and physical variables over a range of scales in marine environments but a
Authors
Christian E. Torgersen, Robert E. Gresswell, Douglas S. Bateman