Treesearch

In western Oregon and Washington, recent changes in federal forest management policy contained in the Northwest Forest Plan have led to new harvest prescriptions on millions of acres of public lands. For example. on upland sites, standards and guidelines now require that live (green) trees are retained in at least 15% of the area within each harvest unit and recommend that at least 70% of this retention is in patches of moderate to larger size (0.2- 1.0 ha or more). These prescriptions [-'or green-tree retention were based on the professional judgment and collective knowledge of many of...

About 90 percent of the land in Maine is in forests. We analyzed past land use trends in Maine and developed projections of future land use. Since the 1950s, the area of forest in Maine has increased by almost 400,000 acres; however, the trends differ among ownerships, as the area of nonindustrial private timberland declined by 800,000 acres since 1950, while private industrial area rose by 681,000 acres. We used econometric analyses to identify variables affecting land allocation, such as population density. Estimated equations were used to generate decadal land use projections to 2050....

Controlled-exposure studies have shown that several plant species native to the Pacific Northwest are potentially sensitive to elevated ambient concentrations of tropospheric ozone. This guide reports visual and descriptive documentation of ozone injury symptoms for common tree, shrub, and herbaceous species in the region. Symptoms observed in leaves of these species include chlorotic mottle, pigmented stipple, necrosis, and premature senescence, with considerable variation among and within species. Resource managers and scientists can use the photo documentation in this guide to identify...

This report describes the logic and design of an effectiveness monitoring program for the Northwest Forest Plan. The program is prospective, providing an early warning of environmental change before irreversible loss has occurred. Monitoring is focused at two resource levels: individual species and specific ecosystem types. Selection of prospective indicators for the status of species or ecosystems is based on the development of conceptual models relating resource change to reliable, early warning signals of change. Ecosystems, such as late seral stage forest communities, are monitored on...

Mortality and growth of self and outcross families of three wind-pollinated, mixed-mating, long-lived conifers, Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), and noble fir (Abies procera) were followed from outplanting to age 26 (25 for noble fir) in spaced plantings at a common test site. Response to inbreeding differed greatly among species over time and in all regards. Only Douglas-fir and noble-fir will be contrasted here, because ponderosa pine usually was intermediate to the other two in its response to inbreeding. In earlier reports, compared to noble fir...

The USDA Forest Service Pacific Northwest Research Station in Corvallis, Oregon, has developed the ecosystem management decision support (EMDS) system. The system integrates the logical formalism of knowledge-based reasoning into a geographic information system (GIS) environment to provide decision support for ecological landscape assessment and evaluation. The knowledge-based reasoning schema of EMDS uses an advanced object- and fuzzy logic-based propositional network architecture for knowledge representation. The basic approach has several advantages over more traditional forms of...

This paper presents long-term resource production from National Forests in the Northern and Intermountain Regions, Regions 1 and 4, respectively. A historical data series of timber harvest and grazing levels on National Forests and lumber production and prices for these regions is developed. Significant trends within the data set are examined. A simple model based on derived demand concepts is tested to identify periods of possible structural change within the stumpage markets for the Region 1 data. This information provides a baseline data set of interest to policymakers and researchers...

This report describes options for effectiveness monitoring of long-term status and trends to evaluate the success of the Northwest Forest Plan in maintaining and restoring marbled murrelet nesting habitat and populations on Federal lands. A two-phase approach is described that begins with developing reliable and repeatable processes for identifying nesting habitat and overcoming logistical and statistical problems before habitat and population trends can be accurately assessed. The second phase involves application of these processes to mapping and quantifying nesting habitat, and establish...

Of the many processes that generate gene duplications, polyploidy is unique in that entire genomes are duplicated. This process has been important in the evolution of many eukaryotic groups, and it occurs with high frequency in plants. Recent evidence suggests that polyploidization may be accompanied by rapid genomic changes, but the evolutionary fate of discrete loci recently doubled by polyploidy (homoeologues) has not been studies. Here we use locus-specific isolation techniques with comparative mapping to characterize the evolution of homoeologous loci in allopolyploid cotton (Gossypium...

We varied the number of red alder retained with 300 Douglas-fir per acre on a high-quality site in coastal Oregon. Alder densities of 0, 20, 40, and 80 per acre were tested. Our fifth treatment eliminated nitrogen-fixing alder, but substituted nitrogen fertilizer. Treatment 6 had neither thinning nor alder control. Treatments were randomly assigned within each of three blocks in a 9-year-old plantation. In pure Douglas-fir plots, gross volume growth was similar for nonfertilized plots, indicating no measurable benefits of additional nitrogen. In mixed stands, red alder reduced yield of...