Treesearch

The study examined the effect of Frankia, macronutrients, micronutrients, mycorrhizal fungi, and plant-growth-promoting fluorescent Pseudomonas sp. on total biomass, nodule weight, and nitrogen fixation of red aider (Alnus rubra) and snowbrush (Ceanothus velutinus) under greenhouse conditions. The soil samples were collected from a 10-year-old clearcut on the H.J. Andrews Experimental Forest, Oregon. Within the clearcut, four sampling points were selected along a slope gradient. Red alder and snowbrush plants were greenhouse-grown in a mix of sod-vermiculite-perlite (2:1:1) for 6 and 12...

The objective of this study was to determine if prescribed fire affects spider (Araneae) and carabid beetle (Carabidae) abundance, and whether the magnitude of this effect varies with time since fire. Within mixed conifer stands; nine understory fuels-reduction burns, ranging from 120 species, and 14,793 carabid beetles from 17 species, were identified from the samples. Seven spider families and five species of carabid beeries were abundant enough to be analyzed statistically. Four spider families were more abundant in unburned sites (Antrodiaetidae, Cybaeidae, Thomisidae mad Linyphiidae)...

By 2050, US timberland area is projected to be about 3 percent smaller than today due to increasing demands for urban and related land uses from another 126 million people. An increasing area of southern planted pine will be accompanied by a reduction in the area of upland hardwoods. Hardwoods will continue to dominate the forested landscape in the South. Plantation growth rates will increase by 38 percent, and plantation fiber output will increase by 289 percent to reach 61 percent of private softwood removals volume.

This report analyzes how a small group of Forest Service scientists participating in efforts to implement adaptive management approach working relations, and how they understand and apply the research process. Nine scientists completed a questionnaire to assess their preferred mode of thinking (the Herrmann Brain Dominance Instrument), engaged in a facilitated conversation to "map" their ideas about research (Conceptual Content Cognitive Mapping, or "3CM"), and participated in several open-ended interviews. Recommendations are made for future adaptive management efforts, and propositions...

The effects of partial cutting on species composition, stand structure and growth, tree size distribution, and tree disease and mortality were evaluated on 73 plots in 18 stands that were harvested 12–96 years ago in southeast Alaska. Partially-cut stands had diverse and highly complex stand structures similar to uncut stands. Sitka spruce was maintained in mixed hemlock–spruce stands over a wide range of cutting intensities. Analysis of the data did not detect significant changes in tree species composition, stand growth, hemlock dwarf mistletoe infection and incidence of tree wounding or...

Information on the diet of the American marten (Martes americana) is vital to understanding habitat requirements of populations of this species. The frequency of occurrence of prey items found in 1014 scat samples associated with 31 radiocollared American martens in northeastern Oregon included: 62.7% vole-sized prey, 28.2% squirrel-sized prey, 22.4% insects, 19.5% birds, 13.3% plant material, and 2.4% lagomorphs. A significantly higher proportion of voles (Microtus spp.), southern red-backed voles (Clethrionomys gapperi), and chipmunks (Tamias spp.) were found in the summer diet compared...

Results of the Stampede Creek installation of the levels-of-growing-stock (LOGS) study in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) are summarized. To age 63 (planned completion of 60 feet of height growth), volume growth on the site III natural stand has been strongly related to level of growing stock, but basal area growth-growing stock relations were considerably weaker. Marked differences in tree size distributions have resulted from thinning. Periodic annual volume increments at age 63 are two to three times greater than mean annual increment; this stand is still far from...

We conducted a regional-scale evaluation of landscape permeability for large carnivores in Washington and adjacent portions of British Columbia and Idaho. We developed geographic information system based landscape permeability models for wolves (Canis lupus), wolverine (Gulo gulo), lynx (Lynx canadensis), and grizzly bear (Ursus arctos). We also developed a general large carnivore model to provide a single generalization of the predominant landscape patterns for the four focal species. The models evaluated land cover type, road density, human population density, elevation, and slope to...

The following management tools can help meet multiple values—environmental, economic, and aesthetic—when used collectively and according to a well-devised plan. Cavity Tree Creation Coarse Woody Debris Augmentation Underplanting Conservation of Biological legacies Variable-Density Thinning Extended Harvest Rotations

Thinning and retention of biological legacies (large live, dead, and fallen trees and their associated biota) during clearcutting are two practices to promote development of late-seral attributes in second-growth forests. We evaluated the effects of these practices on production of truffles and use of truffles as food by northern flying squirrels and Townsend’s chipmunks in 55-65-yr-old Douglas-fir forests in the Puget Trough of Washington. Truffles were collected at 6-wk intervals from March 1993 through December 1995. Feces were collected from flying squirrels and chipmunks in fall and...