Treesearch

To preserve and recover evolutionarily significant units (ESUs) of anadromous salmonids Oncorhynchus spp. in the Pacific Northwest, long-term and short-term ecological processes that create and maintain freshwater habitats must be restored and protected. Aquatic ecosystems through- out the region are dynamic in space and time, and lack of consideration of their dynamic aspects has limited the effectiveness of habitat restoration programs. Riverine-riparian ecosystems used by anadromous salmonids were naturally subjected to periodic catastrophic disturbances, after which they moved through...

Provides current information on lumber and plywood production and pdces; employment In the forest industries; international trade In logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related Items.

A study of Pacific yew (Taxus brevifolia Nutt.) population dynamics in the mountains of western Oregon and Washington was based on a combination of long-term population data and computer modeling. Rates of growth and mortality were low in mature and old-growth forest stands. Diameter growth at breast height ranged from 0 to 3 centimeters per decade. The annual mortality rate for individuals >5 centimeters in diameter at breast height was about 1 percent of the population. A matrix population model was constructed by using these and other fundamental data on yew population dynamics. The...

Prevention of damage to riparian areas from cattle grazing is essential for sound watershed management. Various stubble heights of the most palatable species are used to predict when unacceptable impacts-heavy use or trampling, or both-are about to occur. Managers can observe stubble height and usage and recommend moving the cattle if undesirable effects from continued livestock grazing are anticipated. Three guides for determining when to move cattle are presented: (1) stubble height approaches 3 inches; (2) stubble height changes from 3 inches to 3/4 of an inch; and (3) the most palatable...

A classification of forest vegetation is presented for the Wenatchee National Forest (NF). It is based on potential vegetation, with the plant association as the basic unit. The sample includes about 570 intensive plots and 840 reconnaissance plots distributed across the Wenatchee National Forest and the southwest portion of the Okanogan National Forest from 1975 through 1994. The hierarchical classification includes 10 forest series and 104 types (plant association or community type). Diagnostic keys and descriptions are presented for each tree series and type. Detailed descriptions are...

Giant sequoia [Sequoiadendron giganteum (Lindl.) Buchholz] groves are found entirely within the Sierra Nevada mixed-conifer type. Several of its companion tree species, mainly ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (P. jeffreyi Grev. & Balf.), show foliar injury after exposure to present levels of ozone in the southern Sierra Nevada. Observations at nine giant sequoia groves in Sequoia National Park from August 1983 through September 1986 showed that surviving seedlings in 1986 averaged 18 percent of the original number. These observations did not provide...

There has been much debate about the effect of increased atmospheric CO2 concentrations on plant net primary production1,3 and on net ecosystem CO2 flux3–10. Apparently conflicting experimental findings could be the result of differences in genetic potential11–15 and resource availability16–20, different experimental conditions21–24 and the fact that many studies have focused on individual components of the system2,21,25–27 rather than the whole ecosystem. Here we present results of an in situ experiment on the response of an intact native ecosystem to elevated CO2. An undisturbed patch of...

This report responds to the request by Speaker Foley and Senator Hatfield for a scientific evaluation of the effects of Forest Service management practices on the sustainability of eastern Oregon and Washington ecosystems. The report recommends analysis methods and management practices that can be used to build an experimental approach to the restoration of stressed ecosystems. A total of 113 scientists from universities, Federal and State agencies, and private companies, contributed to this report. Their research provides the basis for a sustainable ecosystem management framework to...

SBexpert version 1.0 is a knowledge-based decision-support system for spruce beetle (Dendroctonus rutipennis (Kby.)) management developed for use in Microsoft Windows with the KnowledgePro Windows development language. The SBexpert users guide provides detailed instructions on the use of all SBexpert features. SBexpert has four main topics (subprograms): Introduction, Analysis, Textbook, and Literature. Introduction is the first of five subtopics in the SBexpert help system. Analysis is an advisory system for spruce beetle management that provides recommendations for reducing spruce beetle...

Tree seedling exposure studies, covering a wide range of experimental conditions in pollutant treatments, species, facilities, and exposure regimes, have been conducted during the past several years to determine acute effects and relative sensitivity of tree species in response to simulated acid precipitation and gaseous pollutants. Because of tile difficulties inherent in conducting controlled exposures with mature trees (e.g., size, variability among experimental units, and costs associated with replication of treatments), seedling exposure studies have been initiated as the quickest way...