Treesearch

To monitor consequences of past operational practices, we installed eight 0.05-acre plots in a 9-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantation established after clearcutting a grossly overstocked stand on a poor-quality site. Logging slash was broadcast burned on half this clearcut. One plot sampled the slash-burned portion, and seven sampled the nonburned portion. Of these, two were in areas thinned 3 years earlier by machete combined with pulling smaller seedlings four were in areas thinned by chainsaw, and one was in a nonthinned strip. Depending...

Growth and mortality in a ponderosa pine (Pinus ponderosa Dougl. ex Laws.) stand were investigated for 24 years. High mortality rates from mountain pine beetle (Dendroctonus ponderosae Hopkins) occurred on some plots where values for stand density index exceeded 140. Periodic annual increments for quadratic mean diameters decreased curvilinearly as stand density increased, whereas periodic annual increments of gross basal area and gross cubic volume increased curvilinearly with increasing stand density. Cubic volume yield at a stand age of 84 years increased linearly with increasing...

We investigated the distribution of biomass and nutrients in second-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems in central Oregon. Destructive sampling of aboveground and belowground tree biomass was carried out at six sites in the Deschutes National Forest; three of these sites also were intensively sampled for biomass and nutrient concentrations of the soil, forest floor, residue, and shrub components. Tree biomass equations were developed that related component biomass to diameter at breast height and total tree height. No significant differences in equation...

Tree numbers, height, and volume were determined in six 63- to 66-year-old plantations of coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in northwest Washington. These stands resulted from the first extensive plantings of this species in the Pacific Northwest. Data from 0.25-acre plots in these plantations were compared to those from matched plots in adjacent, naturally regenerated stands with the same history of logging, wildfire, and absence of further silviculture after regeneration. Planting resulted in well-stocked Douglas-fir stands with volunteers of other...

Dendroecology methods were used to reconstruct a three-century history of western spruce budworm and Douglas-fir tussock moth outbreaks in the Blue Mountains of northeastern Oregon. Comparisons of 20th century Forest Service documentary records and host and nonhost tree-ring width chronologies provided an objective basis for distinguishing climatic effects from insect-caused defoliation effects. Budworm outbreaks were more confidently reconstructed than were tussock moth outbreaks. Since A.D. 1700, at least eight regional budworm outbreaks have occurred at intervals of about 21 to 53...

Forest managers in the Pacific Northwest are faced with new challenges of providing for all wildlife in managed forests. Our objective was to elucidate the factors governing the composition and biomass of forest floor mammal communities that are amenable to management. We sampled small mammal communities in forests of various management histories on the Olympic Peninsula and contrasted our results with those of other large studies in the Pacific Northwest. Forest floor mammal communities in forests >35 yr old in the Western Hemlock Zone of Washington and Oregon are composed of 5-8 character...

Implications of the interim comprehensive strategy for improved Pacific salmon and steelhead habitat management (PACFISH) were estimated for those Bureau of Land Management (BLM) districts and National Forest System (NFS) lands west of the Rocky Mountains that have anadromous fish. The physical impacts and associated mitigation costs from implementing the PACFISH strategy over the the next decade in Pacific Northwest, Intermountain, Northern, Pacific Southwest, and Alaska Region National Forest and BLM district recreation, range, and timber programs were analyzed with the actual current...

Laminated root rot, caused by Phellinus weirii (Murr.) Gilb., is a serious root disease affecting Douglas-fir and other commercially important species of conifers in northwestern North America. This report gives an overview of the dis-ease as it occurs in the Pacific Northwest in Canada and the United States. Information on recognizing crown symptoms and signs of the disease is presented. The disease cycle of laminated root rot, from initiation to intensification and distribution within infected stands, is described. Finally, disease management strategies during stand development and at...

Definitions and codes for identifying vegetation seral status and structure are desired for land management planning, appraising wildlife habitat, and prescribing vegetation treatment. Codes are only presented; they are not a system for determining seral status or stand structure. Terms defined are climax, potential natural community (PNC), succession, seral status, thresholds, altered PNSs, life-form layer, dominant species, successional indicator species, structure classes, cover, and strata. Plant communities may be divided into three life-form layers where appropriate: tree, shrub, and...

We analyzed likely patterns of distribution and persistence of northern spotted owls (Strix occidentalis caurina) on the Olympic Peninsula. Analysis focused on the effects of Federal habitat under provisions of the Northwest Forest Plan; additional benefits to the owl population of different levels of habitat retention on non-Federal lands; effects of establishing a habitat connection between the Olympic Peninsula and other parts of the owl's range; the likely rate of habitat regrowth in the National Forest and its effect on the owl population; and the likely effect of a worst-case fire....