Treesearch

The seasonal and spatial patterns of dispersal of white spruce (Picea glauca (Moench) Voss) seed were studied from 1986 to 1989 in floodplain stands along the Tanana River near Fairbanks, Alaska. Analysis of the 1987 crop showed that production of filled seed was strongly related to estimated production of total seed and unrelated to selected stand structural characteristics. A mathematical expression, developed to estimate dispersal of filled seed into clearcut openings, predicted dispersal between 10 and 120 meters from the edge of an opening. The pattern of wind during the seed-dispersal...

Cones were collected from 272 trees at 189 locations uniformly distributed over the east slopes of the Oregon Cascade Range and Warner Mountains. Variation in seed and seedling traits was related to (1) seed source latitude, distance from the Cascade crest, elevation, slope, and aspect in multiple regression analyses; and (2) seed zone and elevation band in classification analyses. Provisional seed transfer guidelines are presented. These include a regression equation for guiding seed transfer and estimating transfer risk, and a new outline of fixed seed zones.

A proceedings of a conference held to stimulate interaction among people working in areas of forest protection and silviculture and on issues of national and international concern relative to forest insect and disease management, education, and research. National issues addressed were forest productivity, stewardship, biological diversity, and new perspectives and how these issues affect environmentally sound management of forest pests.

Forest Service air resource managers in the Pacific Northwest are responsible for protecting class 1 wilderness areas from air pollution. To do this, they need scientifically defensible information to determine critical concentrations of air pollution having the potential to impact class 1 wilderness values. This report documents the results of a workshop where current information on air pollution effects on aquatic and terrestrial resources and visibility was gathered from participating scientists and managers. Critical air pollution concentrations were determined for sulfur dioxide,...

A recent lumber recovery study of pruned and unpruned ponderosa pine (Pinus ponderosa Dougl. ex Laws.) was used to project the financial return from pruning ponderosa pine in the Medford District of the Bureau of Land Management and in the Ochoco and Deschutes National Forests. The cost of pruning at which the investment would yield an expected 4-percent real rate of return was positive on sites where individual tree growth is fairly high, pruning is done as early as biologically possible given crown removal limitations, and the harvest is 30 to 70 years after pruning. The better situations...

Data collected in conjunction with the multiresource inventory of southeast Alaska in 1985-86 included downed wood along 234 transects at 60 locations. Transects occurred in 11 forest types and 19 plant associations within the entire southeastern Alaska archipelago. Downed wood weights in forest types ranged from 1232 kilograms per hectare (0.6 ton per acre) in muskeg (shore pine) stands to 117 483 kilograms per hectare (52.4 tons per acre) in western redcedar stands. In plant association terminology, downed wood weights ranged from 3115 kilograms per hectare (1.4 tons per acre) in the...

A protocol for sampling forest canopy gaps is presented. Methods used in published gap studies are reviewed. The sample protocol will be useful in developing a broader understanding of forest structure and dynamics through comparative studies across different forest ecosystems.

Scientific, management, and social factors that have contributed to changes in United States forest management are examined. Principles underlying new approaches are developed and implications are considered at various spatial and temporal scales. A general framework for a research program is outlined.

Economic implications of critical habitat designation (CHD) for salmon in the Columbia River basin were estimated in advance of actual designation and recovery plan development. Economic impacts on Pacific, Northwest, Intermountain, and Northern Region National Forests' range, recreation, timber, and mineral programs in the Columbia and Snake River basins were analyzed. Two cases were considered: a worst case, where CHD results in a total reduction in the anadromous portions of the various programs, and a mitigated case, where all or part of the loss is mitigated. Results were analyzed...

Field tests of the load-carrying capacity of epoxy-grouted rock anchors in poor quality bedrock on Wrangel Island in southeast Alaska demonstrated the effectiveness of rock anchors as substitutes for stump anchors for logging system guylines. Ultimate capacity depends mainly on rock hardness or strength and length of the imbedded anchor.