Treesearch

We provide efficient and accurate methods for sampling snags and large trees on a landscape to conduct compliance and effectiveness monitoring for wildlife in relation to the habitat standards and guidelines on National Forests. Included online are the necessary spreadsheets, macros, and instructions to conduct all surveys and analyses pertaining to estimation of snag and large tree densities and distributions at the subwatershed scale. The methods focus on optimizing sampling effort by choosing a plot size appropriate for the specific forest conditions encountered. Two methods are...

Bushy-tailed woodrats (Neotoma cinerea) and dusky-footed woodrats (N. fuscipes) add substantially to the prey base of many avian and mammalian predators. High biomass of woodrats can reduce markedly area requirements of predators; thus, management for woodrats has potential in conservation. But patterns of abundance of woodrats in the Pacific Northwest are poorly understood. Our objective was to determine local abundances and regional distributions of N. cinerea and N. fuscipes in forests west of the Crest of the Cascade Range in Oregon and Washington. We sampled a variety of forests from...

Although ecosystem management techniques are designed to enhance species diversity in managed forests, no comprehensive study has been conducted to evaluate effects of such techniques on diversity and productivity of hypogeous fungi (truffles). During this study, truffles were collected in a 55- to 65-year-old Douglas-fir forest from March 1993 through December 1995 at approximately 6-week intervals. Half of the stands served as controls, half were assigned a variable density thinning (VDT) treatment. A VDT stand comprised a mosaic of patches thinned to different densities of standing live...

Silvicultural practices can influence black bear (Ursus americanus) foraging preferences for Douglas-fir (Pseudotsuga menziesii) cambial-zone vascular tissues, but little is known about the role of genetics. To study the impact of genetic selection, vascular tissue samples were collected from Douglas-fir trees in six half-sib families from five different sites in north central Oregon. Four replications of three-tree non-contiguous plots were sampled at each site to examine inter- and intra-site variation. Tree growth was measured as tree diameter at breast height and the absolute concentrat...

Diminishing quantities of appearance grade lumber and rising price premiums for it have accompanied the transition from old-growth to young-growth timber. The price premiums for better grades are an incentive for producers to undertake investments to increase the yield of those higher valued products. Price premiums, however, are also an incentive for users to substitute lower grades, lower priced species, or nonwood materials for these higher priced appearance grades. This possibility may cast doubt on the permanence of the price premiums associated with appearance grade lumber. The real...

This issue of Science Findings examines the results of a study designed to provide a broad array of silvicultural options for land managers. Pacific Northwest Research Station scientist Mike McClellan is leading the study and has found that timber harvesting by using alternatives to clearcutting is viable in the current marketplace and technically feasible across a wide range of cutting intensity. Other findings have shown that moderate, partial cutting encourages diverse understory vegetation, similar to vegetation found in adjacent uncut old-growth stands. The effectiveness of a wide...

We reviewed existing data to determine the range and distribution of steelhead (Oncorhynchus mykiss) in southeast Alaska, summarized biological characteristics, and determined population status of steelhead stocks. Unique or sensitive stocks that may require consideration in planning land management activities are identified within the data reviewed. Data sources were personal communications, reports, and unpublished data files of State and Federal agencies. Only eight winter-run stocks in southeast Alaska and two summer-run stocks in southwest Alaska had sufficient data to evaluate...

Using hierarchical clustering techniques, we grouped subwatersheds on the eastern slope of the Cascade Range in Washington State into ecological subregions by similarity of area in potential vegetation and climate attributes. We then built spatially continuous historical and current vegetation maps for 48 randomly selected subwatersheds from interpretations of 1938-49 and 1985-93 aerial photos, respectively, and attributes cover types, structural classes, and potential vegetation types to individual patches by modeling procedures. We estimated a natural range of variation (NRV) in spatial...

Survival and growth of planted Douglas-fir (Pseudotsuga menziesii) saplings and associated shrubs were observed for 6 years after seven release treatments had been applied, side by, side on four areas in the Coast Range of Oregon. Four times as much Douglas-fir volume as in the control was produced by one manual cutting of shrubs, which also represented the best economic return. Diversity of competing species temporarily increased after the release treatments.

A study encompassing 24 years was conducted to determine if a breeding program could produce highly graft-compatible rootstocks. Twenty-seven trees of apparent high graft compatibility were selected and crossed to produce 226 control-pollinated families. Seedlings were grown, field planted, and grafted with test scions. Graft unions from field tests were evaluated anatomically for internal symptoms of incompatibility. Average compatibility of progeny from the 226 crosses was 90.6% compared with 65% in native populations. Breeding values were calculated for each parent by the best linear...