Treesearch

This study assesses the incremental economic and environmental impacts resulting from changes in the timing and scope of forest products tariff reductions as proposed in the Accelerated Tariff Liberalization (ATL) initiative in forest products. This initiative was proposed for agreement among member countries of the World Trade Organization. The analysis of environmental effects focuses on possible changes in timber harvest, in the United States and worldwide, and rests directly on an analysis of the economic (trade, production, and consumption) effects of the initiative. The analysis is...

Data from 1999 and 2000 field studies regarding the dispersal flight and initial attack behavior of the spruce beetle (Dendroctonus rufipennis Kirby) are summarized. More dispersing beetles were trapped in flight near the middle to upper tree bole than the lower bole. There were no significant differences between trap location and ambient temperatures. Initial attacks, however, were concentrated on the lower tree bole. Dispersal flight preceded initial attacks by 1 to 2 weeks.

Assessment of the historical disturbance effects across landscapes can provide an important foundation for land management decisions aimed at ecosystem restoration and maintenance. There have been numerous investigations regarding the historic disturbance patterns and resulting stand characteristics in low-elevation, dry forests of the inland west (Arno 1995, Everett et al 1999), yet little research has been concluded locally in subalpine forest communities. Subalpine forests include subalpine fir (Abies lasiocarpa), mountain hemlock (Tsuga mertensiana), whitebark pine (Pinus albicaulis),...

Continuous populations identified as Pacific and North Plateau races of ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) are parapatric along the crest of the Cascade Range in southern Oregon. A 3-year common-garden study of bud phenology and seedling vigor was performed to estimate the nature and magnitude of differentiation between races, to characterize the transition zone between them, and to relate responses between and within races to topography and climate. Principal component (PC) analyses identified two significant character complexes, PC-1 (phenological traits) and PC-2...

This talk outlines four principles that are critical to successful management of a riparian area. First, given problems both with defining historic conditions and with returning to them, attaining management goals based on restoration of ecological processes and functions will be far more successful. Second, the management goals for any stream reach must be placed in a watershed context. Ecological and hydrologic processes that occur above a target stream reach can determine whether many stream reach-specific goals can be met. Third, riparian systems are dynamic, and disturbance is normal...

In June 1977, we surveyed seven research natural areas (RNAs) in the Tongass National Forest (Tongass). We documented the composition of biotic communities using rare plant and tidal community surveys, targeted searches for rare animals, and samples of permanent vegetation plots. Birds were sampled once along each transect with 10-minute point counts at stations 8 through 11 spaced at 250-m intervals. A total of 84 point-count stations was classified according to plant association. Mammals were sampled for two nights along the initial 1.25-km segment of each transect by establishing trap...

Summary estimates are presented of forest resource area, timber volume, and growth and mortality of timber on unreserved national forest land in the Ketchikan inventory unit of the Tongass National Forest. Pacific Northwest Research Station, Forest Inventory and Analysis crews collected inventory data from 1995 to 1998. Productive forest land area (timberland) was estimated at 1,405 thousand acres, cubic-foot volume on timberland at 7,294 million cubic feet, and net annual growth and mortality at 14,158 and 49,568 thousand cubic feet, respectively.

We developed an empirical model describing the probability that forests and farmland in western Oregon and western Washington were developed for residential, commercial, or industrial uses during a 30-year period, as a function of spatial socioeconomic variables, ownership, and geographic and physical land characteristics. The empirical model is based on a conceptual framework of landowners maximizing the present value of the future stream of net returns derived from various land uses. The empirical model is used to compute indices representing 50-year projections of future land use and...

Land management professionals (foresters, wildlife biologists, range managers, and land managers such as ranchers and forest land owners) often have need to evaluate their management activities. Photographic monitoring is a fast, simple, and effective way to determine if changes made to an area have been successful. Ground-based photo monitoring means using photographs taken at a specific site to monitor conditions or change. It may be divided into two systems: (1) comparison photos, whereby a photograph is used to compare a known condition with field conditions to estimate some parameter...

Predicting sediment production from forest roads is necessary to determine their impact on watersheds and associated terrestrial and stream biota. A method is presented for measuring sediment originating from a road segment for individual storm events and quantifying the delivery to streams. Site selection criteria are listed to describe the characteristics for efficient data collection and analysis. The method describes equip-ment used to quantify sediment transport—data loggers, a rain gage, a traffic counter, Parshall flumes with stilling wells, hydrostatic pressure transducers, and...