Treesearch
Search National Treesearch
Displaying 5,461 - 5,470 of 6,801 Publications
- Adaptive genetic variation in seed and seedling traits for ponderosa pine from the east slopes of the Cascade Range in Oregon was analyzed by using 307 families from 227 locations. Factor scores from three principal components based on seed and seedling traits were related by multiple regression to latitude, distance from the Cascade crest, elevation, slope, and aspect of the seed source and by classification analysis to seed zone and 300-meter elevation band within zone. A provisional transfer risk equation and tentative new seed zones were delineated to guide seed transfer in artificial...AuthorsFrank SorensenKeywordsSourceRes. Pap. PNW-RP-472. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 24 pYear1994
- Portions of forest ecosystems in eastern Oregon and Washington are in poor health, are not meeting societies expectations, and have elevated hazard for fire, insects, and disease. Diversity in stream habitats and associated fisheries has declined over the last several decades in several drainage basins, requiring conservation and restoration efforts in key watersheds. Required first steps in restoring forest and aquatic ecosystems are the immediate reduction in hazard for catastrophic loss of biodiversity, site quality, resource commodities, and improved conditions for public health. To...AuthorsRichard L. EverettKeywordsSourceGen. Tech. Rep. PNW-GTR-330. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 123 p. (Everett, Richard L., assessment team leader; Eastside forest ecosystem health assessment; volume IV.)Year1994
- Procedures for monitoring larval populations of the Douglas-fir tussock moth and the western spruce budworm are recommended based on many years experience in sampling these species in eastern Oregon and Washington. It is shown that statistically reliable estimates of larval density can be made for a population by sampling host trees in a series of permanent plots in a geographical monitoring unit. The most practical method is to estimate simultaneously densities on a plot of both insect species by the nondestructive sampling of foliage on lower crown branches of host trees. This can be...AuthorsA.R. Mason, H.G. PaulKeywordsSourceGen. Tech. Rep. PNW-GTR-333. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 pYear1994
- Productivity of forest and range land soils is based on a combination of diverse physical, chemical and biological properties. In ecosystems characteristic of eastside regions of Oregon and Washington, the productive zone is usually in the upper 1 or 2 m. Not only are the biological processes that drive both soil productivity and root development concentrated in limited organic horizons, but also they have evolved historically in a natural system that includes mostly modest surface disturbance. Typical disturbances include erosional, seismic, or tip-over events, and modest surface heating...AuthorsAlan E. Harvey, J. Michael Geist, Gerald L McDonald, Martin F. Jurgensen, Patrick H. Cochran, Darlene Zabowski, Robert T. MeurisseKeywordsSoil management strategy, soil productivity, soil sustainability, soil damage, soil moisture, soil microbiology, soil-disease interaction, soil-climate interaction, soil wood, coarse woody debris, organic matter, water storage and use, nutrient cycling, nitrogen ?xation, ectomycorrhizal activity, carbon cycling, harvest effects, ?re effects, fertilizer effects, forest health, physical properties, chemical propertiesSourceGen. Tech. Rep. PNW-GTR-323. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.Year1994
- Traces the natural and cultural processes involved in shaping the environment in the intermontane northwest from the Indian period of domination to the present. Emphasizes the increasing influence of humans as modifiers of landscapes and ecosystems, especially with the coming of the market system to the region and the onset of the industrial era. Focuses on the unique aspects of ecological change in the intermontane region: the very recent extension of the market system to the area; and the very rapid expansion of human-induced environmental disturbance over very extensive areas in a very...AuthorsWilliam G. Robbins, Donald W. WolfKeywordsSourceGen. Tech. Rep. PNW-GTR-319. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 32 p. (Everett, Richard L., assessment team leader; Eastside forest ecosystem health assessment; Hessburg, Paul F., science team leader and tech. ed., Volume III: assessment.)Year1994
- New approaches and technologies to evaluate wildlife-habitat relations, implement integrated forest management, and improve public participation in the process are needed to implement ecosystem management. Presented here are five papers that examine ecosystem management concepts at international, national, regional, and local scales. Two general management problems were addressed: how to incorporate different components of ecosystem management into specific forestry and wildlife management practices, and how to resolve conflicts and involve citizens more effectively in the management...AuthorsMark H. Huff, Lisa K. Norris, J. Brian Nyberg, Nancy L. Wilkin, coords.KeywordsSourceGen. Tech. Rep. PNW-GTR-336. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Station, 100 p. (Huff, Mark H.; McDonald, Stephen E., Gucinski, Hermann, tech. coords.; Applications of ecosystem management)Year1994
- A systematic approach to adaptive management is proposed to simultaneously manage at the regional, provincial, and watershed scales and to reorganize the activity of agencies to better support the concepts of adaptive management. Reorganizing management activities into these four groupings is recommended: adjustment (expanded decisionmaking); linked, not single actions; feedback, including monitoring; and information synthesis. A major new focus for the collaborative decision process is to identify and set priorities among possible future adjustments. Linked actions that integrate managemen...AuthorsB.T. Bormann, P.G. Cunningham, M.H. Brookes, V.W. Manning, M.W. CollopyKeywordsSourceGen. Tech. Rep. PNW-GTR-341. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 pYear1994
- Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found for relative crown width; stem increment per crown projection area; leaf area and branch weight relative to crown size; branch diameter and length adjusted for stem size; branch stoutness; cross-sectional area of branches per crown length; and needle size. Little genetic variation was found for branch numbers per whorl, branch angle, and...AuthorsJ.B. St. ClairSourceCanadian Journal of Forest Research. 24: 1236-1247Year1994
- The effects on eastside forest ecosystems from long-term grazing by large mammals are assessed, because long-term herbivory can reduce or increase ecosystem productivity. The assessment emphasizes elk and cattle in the Blue Mountains of northeast Oregon and southeast Washington. Histories of populations of large mammals and their effects in the Blue Mountains are described. Maximum populations of domestic livestock in the Blue Mountains occurred about the turn of the 20th century, declined by 1940, and increased slightly to the present. Livestock grazing on Federal livestock allotments...AuthorsLarry L. Irwin, John G. Cook, Robert A. Riggs, Jon M. SkovlinKeywordsSourceGen. Tech. Rep. PNW-GTR-325. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 49 p. (Everett, Richard L., assessment team leader; Eastside forest ecosystem health assessment; Hessburg, Paul F., science team leader and tech. ed., Volume III: assessment.)Year1994
- From 1934 to 1942, the Bureau of Fisheries surveyed over 8000 km of streams in the Columbia River basin to determine the condition of fish habitat. To evaluate changes in stream habitat over time, a portion of the historically surveyed streams in the Grande Ronde, Methow, Wenatchee, and Yakima River basins were resurveyed from 1990 to 1992. Streams were chosen where the primary impacts were natural disturbance (unmanaged), such as wilderness and roadless areas, and where human impacts (managed) were the major disturbances. In addition, historical changes in land-use, stream flow, and...AuthorsBruce A. McIntosh, James R. Sedell, Jeanette E. Smith, Robert C. Wissmar, Sharon E. Clarke, Gordon H. Reeves, Lisa A. BrownKeywordsSourceGen. Tech. Rep. PNW-GTR-321. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 55 p. (Everett, Richard L., assessment team leader; Eastside forest ecosystem health assessment; Hessburg, Paul F., science team leader and tech. ed., Volume III: assessment.)Year1994