Treesearch

From 1996 through 1999, field tests of various engraver beetle (Ips perturbatus (Eichhoff)) semiochemicals in funnel traps were conducted in south-central and interior Alaska in stands of Lutz (Picea xlutzii Little) and white spruce (P.glauca (Moench) Voss). The European spruce beetle (I. typographus (L.)) is believed to be taxonomically similar to I. perturbatus. Commercially available European spruce beetle lures, which include 2-methyl-3buten-2-ol, however, were no more attractive to I. perturbatus than the combination of racemic ipsdienol and 83%-(+)-cis-verbenol. The addition of...

We collected 490 and 233 fire scars on two ponderosa pine (Pinus ponderosa)/Douglas-fir (Pseudotsuga menziesii) dominated landscapes on the east slope of the Washington Cascades that contained a record of 3901 and 2309 cross-dated fire events. During the pre-settlement period (1700/1750±1860), the Weibull median fire-free interval (WMFFI) and the mean firefree interval (MFFI) were 6.6±7 years at both sites. The MFFI during the settlement period (1860±1910) varied within 3 years of the pre-settlement value, but increased to 38 and 43 years for a truncated fire suppression period between...

An innovative, knowledge-based partnership between research scientists and resource managers in the U.S. Forest Service provided the foundation upon which the Forest Plan was developed that will guide management on the Tongass National Forest for the next 10-15 years. Criteria developed by the scientists to evaluate if management decisions were consistent with the available information base were applied to major components of the emerging final management strategy for the Forest. While the scientists remained value neutral on the contents of the Forest Plan and the management directions...

This document synthesizes research accomplishments initiated and funded under the Northwest Forest Plan or the President’s Forest Plan (hereafter referred to as the Forest Plan) since its inception in 1994. Three major parts in this document cover, the context for this effort, eight Forest Plan research accomplishments, and a synthesis. The eight accomplishments described in part two, chapter 4 are as follows:Wildlife conservation and population variability issues Aquatic conservation strategy Adaptive management concepts and decision support Adaptive management areas: synthesis of an...

The scientific literature on logging after wildfire is reviewed, with a focus on environmental effects of logging and removal of large woody structure. Rehabilitation, the practice of planting or seeding after logging, is not reviewed here. Several publications are cited that can be described as “commentaries,” intended to help frame the public debate. We review 21 postfire logging studies and interpret them in the context of how wildfire itself affects stands and watersheds. Results of this review are summarized in 16 major conclusions at the end of the text, most of which are based on...

Korean pine-broadleaved forests are very biologically diverse. In the Russian Far East, these forests are subject to a high level of use by humans and are systematically influenced by fire. Intensive exploitation in the past has led to a decrease in the resource potential. Sound decisionmaking and scientific advancement have lacked sufficient exchange of scientific information. A symposium was convened to share information through presentations of a comprehensive set of topics including forest structure, seed science, genetics, regeneration, fire, wildlife biodiversity, non-timber forest...

In the interior Columbia River basin midscale ecological assessment, we mapped and characterized historical and current vegetation composition and structure of 337 randomly sampled subwatersheds (9500 ha average size) in 43 subbasins (404 000 ha average size). We compared landscape patterns, vegetation structure and composition, and landscape vulnerability to wildfires and 21 major forest insect and pathogen disturbances of historical and current forest vegetation coverages. We report on methods used to classify and map potential vegetation of individual patches of sampled subwatersheds at...

In three related experiments, root systems of 2-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were dip-inoculated with a viscous blend of Leptographium wageneri var. pseudotsugae Harrington and Cobb spores and hyphal fragments and planted in a sterile potting medium. Infection frequency and points of entry were evaluated for dormant seedlings and seedlings that had been active for 4 and 8 weeks. All putative black stain infections and other areas of sapwood discoloration were free-hand sectioned and examined with a bright-field microscope and phase-contrast optics....

Smoke exposure measurements among firefighters at wildfires in the Western United States between 1992 and 1995 showed that altogether most exposures were not significant, between 3 and 5 percent of the shift-average exposures exceeded occupational exposure limits for carbon monoxide and respiratory irritants. Exposure to benzene and total suspended particulate was not significant, although the data for the latter were limited in scope. The highest short-term exposures to smoke occurred during initial attack of small wildfires, but the shift-average exposures were less during initial attack...

Smoke exposure measurements among firefighters during prescribed burns in the Pacific Northwest between 1991 and 1994 showed that a small but significant percentage of workers experienced exposure to carbon monoxide and respiratory irritants that exceeded occupational exposure limits. This most often was caused by unfavorable winds or fire behavior and occurred mostly among workers involved in maintaining the fire within the prescribed boundaries. Smoke exposure in such peak exposure situations was up to three times above recommended limits. Exposure to acrolein benzene, formaldehyde, and...