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Displaying 5,251 - 5,260 of 6,802 Publications
- A linked model of the US forest and agriculture sectors was used to examine the economic and ecological impacts of two forest policies: a minimum harvest age limitation and a reduced public harvest policy. Simulated private responses to both policies indicate that landowners could undertake a range of adjustments to minimize their welfare impacts, but imposition of constraints on the management of existing timber stocks have particularly potent effects. Environmental changes associated with the responses include: (1) impacts on biodiversity trends and wildlife habitat conditions when...AuthorsR.J. Alig, D.M. Adams, B.A. McCarlKeywordsSourceEcological Economics. 27: 63-78.Year1998
- For the past sixty years, ecologists have been arguing about what an ecosystem is, and the debate continues (Blew 1996; Lenz and Haber 1996). Ecosystem management, however, is an entirely human process that entails not only manipulating and protecting ecosystems but also making private and public goals operational within a larger social environment of public needs, desires, and laws. Since many of the benefits people wish to derive from ecosystems (Table 1) are incompatible, conflicts over natural resource issues are rampant, especially in the Pacific Northwest (Curtis and Carey 1996). In...AuthorsA.B. CareySourceIn: Calhoun, J.M., ed. Forest policy: ready for renaissance. Seattle, WA : College of Forest Resources, University of Washington: 261-273Year1998
- Defoliation by pandora moth in a ponderosa pine spacing study in 1992 and 1994 generally increased as spacings increased from 2 to 5.7 meters and then decreased as spacings increased to 8 meters. Defoliation did not increase mortality during the 1990-94 period, but volume growth was reduced. Basal area increments of sample trees were reduced 25 percent the first growing season after defoliation (1992), 30 percent the second year after defoliation (1993), and 63 percent after the second defoliation (1994AuthorsP.H. CochranKeywordsSourceRes. Note PNW-RN-526. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 14 pYear1998
- Procedures to analyze half-diallel mating designs using the SAS statistical package are presented. The procedure requires two runs of PROC and VARCOMP and results in estimates of additive and non-additive genetic variation. The procedures described can be modified to work on most statistical software packages which can compute variance component estimates. The procedure is relatively simple and provides unbiased estimates for balanced designs and gives good approximations for unbalanced data.AuthorsG.R. Johnson, J.N. KingKeywordsSourceSilvae Genetica. 47(2-3): 74-79Year1998
Late-successional and old-growth forest effectiveness monitoring plan for the Northwest Forest Plan.
This report presents options for long-term effectiveness monitoring of late-successional and old-growth forests under the Northwest Forest Plan. It describes methods to answer questions about how much late-successional forest exists on Federal land, its pattern, how it’s changing, and if the Forest Plan is providing for its conservation and management. It specifies data needed, analytic methods for using remotely sensed and grid plot data, and implementation options. A periodic process for reporting the status and trend of late-successional and old-growth forests on Federal lands is...AuthorsMiles Hemstrom, Thomas Spies, Craig Palmer, Ross Kiester, John Teply, Phil McDonald, Ralph WarbingtonKeywordsSourceGen. Tech. Rep. PNW-GTR-438. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 37 pYear1998- Lists codes for identification of potential natural communities (plant association, habitat types), their seral status, and vegetation structure in and around the Pacific Northwest. Codes are a six-digit alphanumeric system using the first letter of tree species, life-form, seral status, and structure so that most codes can be directly interpreted. Seven appendices list various groupings of codes, a synonymy with plants listing, and a complete list with descriptions of all codes wiht references to publications.AuthorsFrederick C. HallSourceGen. Tech. Rep. PNW-GTR-418. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 290 p. In cooperation with: Pacific Northwest RegionYear1998
- Silvicultural knowledge and practice have been evolving in the Pacific Northwest for nearly a century. Most research and management activities to date have focused on two major topics: (1) methods to regenerate older, naturally established forests after fire or timber harvest; and (2) growth and management of young stands. Today forest managers can reliably regenerate the major conifer and hardwood species under most conditions by using combinations of natural and artificial regeneration. They also can control stand density and species composition and growth of individual trees, thereby...AuthorsR.O. Curtis, D.S. DeBell, C.A. Harrington, D.P. Lavender, J.B. St. Clair, J.C. Tappeiner, J.D. WalstadKeywordsSourceGen. Tech. Rep. PNW-GTR-435. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 123 pYear1998
- Experimental prescriptions compare agroforestry systems designed to increase financial returns from high-elevation stands in the southern Oregon Cascade Range. The prescriptions emphasize alternative approaches for joint production of North American matsutake mushrooms (also known as North American pine mushrooms; Tricholoma magnivelare) and high-quality timber. Other agroforestry byproducts from the system are ornamental conifer boughs, pine cones, and Christmas trees. Management practices concentrate on increasing the physiological efficiency and vigor of trees, and on altering leaf area...AuthorsJames F. WeigandKeywordsSourceGen. Tech. Rep. PNW-GTR-424. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 42 pYear1998
- A fire behavior module was developed for the California Fire Economics Simulator version 2 (CFES2), a stochastic simulation model of initial attack on wildland fire used by the California Department of Forestry and Fire Protection. Fire rate of spread (ROS) and fire dispatch level (FDL) for simulated fires "occurring" on the same day are determined by making coordinated draws from compound distributions characterizing 2 PM fire behavior indices such as ROS, then adjusting these draws using diurnal adjustment coefficients derived from hourly fire weather observations. Statistical examination...AuthorsJ. Keith Gilless, Jeremy S. FriedKeywordsSourceForest Science. 45(4): 492-499Year1998
- This bibliography updates the list of publications, abstracts, theses, and unpublished reports included in "Research Publications of the H.J. Andrews Experimental Forest, Cascade Range, Oregon, 1948 to 1986" (General Technical Report PNW-GTR-201) and "Research Publications of the H.J. Andrews Experimental Forest, Cascade Range, Oregon: 1988 Supplement" (General Technical Report PNW-GTR-223). Citations are referenced under appropriate keywords.AuthorsDonald L. Henshaw, Sarah Greene, Tami LowryKeywordsSourceGen. Tech. Rep. PNW-GTR-427. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 94 pYear1998