Treesearch

Duff consumption by fire was studied on 15 cable-yarded clearcut units in western Oregon and western Washington. Equations are presented that predict duff consumption (in depth reduction and weight loss) from loading, consumption, and moisture of large fuels, and days since significant precipitation. When more than 25 days elapsed since 1.3 cm rainfall, the effect of large fuel loading on duff consumption diminished. Duff consumption was dependent on the diameter reduction of large fuels when there had been no rain for at least 25 days. The results indicated that duff consumption can be...

Growth, stand development, and yield were studied for young, thinned western hemlock (Tsuga heterophylla Raf. [Sarg.]). Two similar studies were located at Cascade Head Experimental Forest in the Siuslaw National Forest, western Oregon, and near Clallam Bay on the Olympic Peninsula in Washington. At the latter, first thinnings were made at two ages; one at about the time of initial crown closure (early or crown closure thinning), and the other after competition was well underway (late or competition thinning). Stands, age 7 at breast height at time of crown closure thinning, were grown for...

Radial-growth recovery related to amount of tree defoliation was measured 10 years after a severe outbreak of Douglas-fir tussock moth (Orgyia pseudotsugata (McDunnough). For the period 1978-82, growth of qrand fir surpassed and was significantly greater than in the preoutbreak period, 1968-72. Douglas-fir growth during the postoutbreak period showed similar patterns, but it was not significantly different from preoutbreak growth for every defoliation class. Growth of undefoliated trees was also greater during the postoutbreak period, indicating that above-normal precipitation aided tree...

This publication lists all completed and current research projects in research natural areas in Oregon and Washington and in those few research natural areas in Idaho that are administered by National Forests in Oregon. The list includes project title, status, source of funding, and principal investigator and address. A list of publications pertaining to research natural areas is also included. Where possible, publications and research projects are correlated. The publication outlines the scientific use and importance of research natural areas as research sites for applied and basic...

Alaska forest products trade flows for 1982 were studied to determine the effects of the Merchant Marine Act of 1920 (the Jones Act). Information was collected from timber producers, forest product industries, and waterborne shippers in Alaska, British Columbia, and the Pacific Northwest. Trade flows were simulated, using a partial equilibrium model based on resource rents, with and without the Jones Act restrictions. Results indicate that $4.77 million in additional costs were incurred in 1982 because of the Jones Act. These effects appeared small, however, relative to the wholesale value...

Systematic, long-term measurements of the survival and growth effects of releasing crop trees from competing vegetation are important for evaluating vegetation management treatments in forest plantations. This report details field-tested procedures for use in any type of release treatment—mechanical, manual, biological, or chemical. The basic concept is to delineate one untreated plot within each plantation to be monitored and to compare survival and growth on that "control" plot with survival and growth on a treated plot that is similarly delineated. Each installation should be examined...

A field guide to predict site index for red alder (Alnus rubra Bong.) was developed for use in western Washington and Oregon. The guide requires the user to evaluate 14 soil-site properties that are grouped into three general factors: (1) geographic and topographic position, (2) soil moisture and aeration during the growing season, and (3) soil fertility and physical condition. Construction of the guide was modeled after a method of site evaluation developed for several southern hardwood species. The red alder model is accurate when used properly. The correlation (r) between predicted and...

Site preparation is often necessary to obtain adequate forest regeneration, but inappropriate treatment may reduce subsequent growth. Broadcast-burned and piled-and-burned plantations were studied in southwestern Oregon to determine if burning method affected the growth of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii). The measured and potential heights of 5-year-old seedlings were about equal where broadcast burning occurred, but measured heights were less than potential heights on most of the piled-and-burned plantations. Site quality probably is damaged by piling and...

A floristic survey of Meeks Table Research Natural Area in the Wenatchee National Forest, Washington, documents 159 vascular plant taxa representing 39 families. This paper provides estimates of abundance by plant community or by other habitat characteristics for all taxa listed. Plant communities are described and mapped based on current vegetation.

This report is one of five that provide timber resource statistics for 57 of the 58 counties in California (San Francisco is excluded). This report presents statistics from a 1981-84 inventory of the timber resources of Lassen, Modoc, Shasta, Siskiyou, and Trinity Counties. Tables presented are of forest area and of timber volume, growth, and mortality. Timberland area is an estimated 5.7 million acres, 40 percent of the total land area. Total growing stock volume is 16 billion cubic feet. The northern interior resource area contains 14 percent of the State’s total land area, 35 percent of...