Publications
Filter Total Items: 1990
Geospatial techniques for developing a sampling frame of watersheds across a region
Current land-management decisions that affect the persistence of native salmonids are often influenced by studies of individual sites that are selected based on judgment and convenience. Although this approach is useful for some purposes, extrapolating results to areas that were not sampled is statistically inappropriate because the sampling design is usually biased. Therefore, in recent investiga
Authors
Robert E. Gresswell, Douglas S. Bateman, George Lienkaemper, T.J. Guy
Modeling demographic performance of northern spotted owls relative to forest habitat in Oregon
Northern spotted owls (Strix occidentalis caurina) are known to be associated with late-successional forests in the Pacific Northwest of the United States, but the effects of habitat on their demographic performance are relatively unknown. We developed statistical models relating owl survival and productivity to forest cover types within the Roseburg Study Area in the Oregon Coast Range of Oregon,
Authors
Gail S. Olson, Elizabeth M. Glenn, Robert G. Anthony, Eric D. Forsman, Janice A. Reid, Peter J. Loschl, William J. Ripple
Movements by juvenile and immature Steller's Sea Eagles Haliaeetus pelagicus tracked by satellite
Twenty-four juvenile Steller's Sea Eagles Haliaeetus pelagicus were tracked via satellite from natal areas in Magadan, Kabarovsk, Amur, Sakhalin and Kamchatka. Nestling dispersal occurred between 9 September and 6 December (n = 24), mostly 14 September-21 October, and did not differ among regions or years. Most eagles made stopovers of 4-28 days during migration. Migration occurred 9 September-18
Authors
M.J. McGrady, M. Ueta, E.R. Potapov, I. Utekhina, V. Marterov, A. Ladyguine, V. Zykov, J. Cibor, Mark R. Fuller, J.K. Seegar
Interactions of cattle grazing and climate change- hierarchical data analysis
No abstract available.
Authors
D. Clausnitzer, Manuela M. P. Huso, David A. Pyke, Jayne Belnap, T. B. Graham, R. L. Sanford, S. L. Phillips
Research observation: Hydrolyzable and condensed tannins in plants of the northwest
Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs oth
Authors
M. P. Gonzalez-Hernandez, J. Karchesy, Edward E. Starkey
Repeated use of ion-exchange resin membranes in calcareous soils
This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use o
Authors
S. K. Sherrod, Jayne Belnap, M. E. Miller
Combining inferences from models of capture efficiency, detectability, and suitable habitat to classify landscapes for conservation of threatened bull trout
Effective conservation efforts for at-risk species require knowledge of the locations of existing populations. Species presence can be estimated directly by conducting field-sampling surveys or alternatively by developing predictive models. Direct surveys can be expensive and inefficient, particularly for rare and difficult-to-sample species, and models of species presence may produce biased predi
Authors
J. Peterson, J. B. Dunham
Rana cascadae (Cascade frog). Cannibalism
No abstract available.
Authors
C.J. Rombough, D.J. Jordan, Christopher A. Pearl
Coexistence in a multispecies assemblage of eagles in central Asia
We evaluated factors that permit species coexistence in an exceptional assemblage of similar raptor species at the Naurzum Zapovednik (a national nature reserve) in north-central Kazakhstan. White-tailed Sea-Eagle (Haliaeetus albicilla), Imperial Eagle (Aquila heliaca), Golden Eagle (A. chrysaetos), and Steppe Eagle (A. nipalensis) all breed at the Zapovednik. Steppe Eagle use of nesting resources
Authors
Todd Katzner, E. Bragin, Steven T. Knick, Andrew T. Smith
Status of native fishes in the western United States and issues for fire and fuels management
Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been viewed as one cause of this prob
Authors
B. Rieman, D. Lee, D. Burns, Robert E. Gresswell, M. Young, R. Stowell, J. Rinne, P. Howell
Fire and aquatic ecosystems of the western USA: Current knowledge and key questions
Understanding of the effects of wildland fire and fire management on aquatic and riparian ecosystems is an evolving field, with many questions still to be resolved. Limitations of current knowledge, and the certainty that fire management will continue, underscore the need to summarize available information. Integrating fire and fuels management with aquatic ecosystem conservation begins with recog
Authors
P.A. Bisson, B. Rieman, C. Luce, Paul F. Hessburg, D. Lee, J. Kershner, G.H. Reeves, Robert E. Gresswell
Introduction to the effects of wildland fire on aquatic ecosystems in the Western USA
The management of wildfire has long been controversial. The role of fire and fire-related management in terrestrial and aquatic ecosystems has become an important focus in recent years, but the general debate is not new. In his recent book, Stephen Pyne (2001 )describes the political and scientific debate surrounding the creation of the U.S. Forest Service and the emergence of fire suppression as
Authors
B. Rieman, Robert E. Gresswell, M. Young, C. Luce