Treesearch

Fifteen years of research on old-growth and managed coniferous forests have provided sufficient understanding of biodiversity to suggest a basis for ecosystem management. First, natural old forests have a metaphysics values associated with their existence and function can never be addressed fully with the scientific method alone; we cannot recreate old growth. Second, five processes underly forest development: crown-class differentiation, decadence, canopy stratification, understory development, and development of habitat breadth. Habitat breadth results from fine scale spatial heterogeneit...

Export constraints affecting North American west coast logs have existed intermittently since 1831. Recent developments have tended toward tighter restrictions. National, Provincial, and State rules are described.

This report present information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rareplants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial...

Big shifts have been made over the last decade in how society thinks forest lands should be managed. Forest policy has subsequently changed. Land managers now grapple with how to make society's intentions work in the forests of today.This issue of PNW Science Findings presents the Colville study's examination of the vast forests of small-diameter wood in the intermountain West. In this region, land managers are working to decrease the risk to forest health from fire, insects, and disease while improving wildlife habitat and aesthetics. In doing so, they are considering how to create the...

A linked model of the US forest and agriculture sectors was used to examine the economic and ecological impacts of two forest policies: a minimum harvest age limitation and a reduced public harvest policy. Simulated private responses to both policies indicate that landowners could undertake a range of adjustments to minimize their welfare impacts, but imposition of constraints on the management of existing timber stocks have particularly potent effects. Environmental changes associated with the responses include: (1) impacts on biodiversity trends and wildlife habitat conditions when...

For the past sixty years, ecologists have been arguing about what an ecosystem is, and the debate continues (Blew 1996; Lenz and Haber 1996). Ecosystem management, however, is an entirely human process that entails not only manipulating and protecting ecosystems but also making private and public goals operational within a larger social environment of public needs, desires, and laws. Since many of the benefits people wish to derive from ecosystems (Table 1) are incompatible, conflicts over natural resource issues are rampant, especially in the Pacific Northwest (Curtis and Carey 1996). In...

Defoliation by pandora moth in a ponderosa pine spacing study in 1992 and 1994 generally increased as spacings increased from 2 to 5.7 meters and then decreased as spacings increased to 8 meters. Defoliation did not increase mortality during the 1990-94 period, but volume growth was reduced. Basal area increments of sample trees were reduced 25 percent the first growing season after defoliation (1992), 30 percent the second year after defoliation (1993), and 63 percent after the second defoliation (1994

Procedures to analyze half-diallel mating designs using the SAS statistical package are presented. The procedure requires two runs of PROC and VARCOMP and results in estimates of additive and non-additive genetic variation. The procedures described can be modified to work on most statistical software packages which can compute variance component estimates. The procedure is relatively simple and provides unbiased estimates for balanced designs and gives good approximations for unbalanced data.

This report presents options for long-term effectiveness monitoring of late-successional and old-growth forests under the Northwest Forest Plan. It describes methods to answer questions about how much late-successional forest exists on Federal land, its pattern, how it’s changing, and if the Forest Plan is providing for its conservation and management. It specifies data needed, analytic methods for using remotely sensed and grid plot data, and implementation options. A periodic process for reporting the status and trend of late-successional and old-growth forests on Federal lands is...

Lists codes for identification of potential natural communities (plant association, habitat types), their seral status, and vegetation structure in and around the Pacific Northwest. Codes are a six-digit alphanumeric system using the first letter of tree species, life-form, seral status, and structure so that most codes can be directly interpreted. Seven appendices list various groupings of codes, a synonymy with plants listing, and a complete list with descriptions of all codes wiht references to publications.