Treesearch

A predictive model is presented to calculate moisture content of 1000-hour timelag fuels in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) logging slash in western Washington and western Oregon. The model is a modification of the 1000-hour fuel moisture model of the National Fire-Danger Rating System and requires daily measurements of precipitation duration, maximum and minimum relative humidities, and maximum and minimum temperatures. Comparison of measured and calculated fuel moisture contents showed good agreement. The model...

A dynamic simulation model has been adapted for use in Alaska. It provides a flexible tool for examining the economic consequences of alternative forest resource management policies. The model could be adapted for use elsewhere if an interindustry transaction table is available or can be developed. To demonstrate the model's usefulness, the contribution of the pulp and paper and tourism industries to Alaska's economy is analyzed. A $105 million increase in final demand for goods and services provided by the tourism industry would compensate for the loss of employment and earnings resulting...

The 10-year growth response from an initial spacing study established in a ponderosa pine (Pinus ponderosa Dougl, ex Laws.) and grand fir (Abies grandis (Dougl. ex D. Don) Lindl.) plantation was measured in central Oregon. The study was designed to compare the growth rates of pure pine, pure fir, and a 50-percent mixture of each species planted at 6-, 12-, and 18-foot spacings. Height growth of pure pine was about twice as great as that of pure fir because of damage to the fir from frost and animals; growth of the pine-fir mixture was intermediate. Both basal area and total cubic volume...

In 1983, a study was conducted to evaluate the effects of leader topping and branch pruning on the efficiency to tree shaking to remove Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) cones. Removal efficiency for three topping and pruning treatments averaged 69 percent, whereas for the uncut control treatment it was 62 percent. The treatment combination that resulted in the greatest cone removal (70.8 percent) was cutting the last 2 years of growth from the leader but not pruning lateral branches. The pruning-topping effects were not additive, possibly because branch pruning several...

Provides current information on lumber and plywood production and prices; 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.

Effects associated with progressive maturation of clones are of greatest concern in clonal tree improvement programs. Serial propagation has been in use at the Lower Saxony Forest Research Institute since 1968 to arrest maturation in Norway spruce clones. By 1980 cuttings were established in the nursery that had been serially propagated from one to five cycles. This material was measured in fall 1983 for several characteristics thought to be indicative of maturation state. Serial propagation appears to have at least considerably slowed, and perhaps arrested, maturation processes in Norway...

Environmental effects of water transportation of logs in western North America include the historical driving of logs in rivers and streams, and the current dumping, sorting, transportation, and storage of logs in rivers and estuaries in British Columbia and southeastern Alaska. The historical discussion focuses on habitat losses and volumes of logs transported by water, both freshwater and marine. Many changes in stream-channel structure and habitat simplification still exist today, nearly 100 years after river-driving activities have ceased. The environmental effects of current log...

Although many effects of forest and rangeland management on anadromous fisheries are difficult to measure, economic methods for the evaluation of costs and benefits can be helpful. Such methods can be used to address questions of equity as well as efficiency. Evaluations of equity can show who bears the costs and who captures the benefits of management actions, but cannot judge the goodness of any particular allocation of cost and benefits. The efficiency of the management and commercial harvest of anadromous fish is determined to a large extent by the regulation of fish harvest. Although...

The diameter and height growth of advance reproduction of suppressed true fir (Abies spp.) and mountain hemlock (Tsuga mertensiana (Bong.) Carr.) was measured in south-central Oregon after release by overstory removal in clearcuttings, shelterwood units, and uncut stands. Postrelease growth was greatest in clearcuttings, intermediate in shelterwood cuttings, and slowest in uncut stands. Multiple regression analyses were used to predict growth response as a function of tree and stand variables. Overstory basal area, live crown ratio, and past 5-year height growth accounted for the most...

During 1980-81, transport of bedload sediment and channel morphology were determined at Trap Bay Creek, a third-order stream that drains a 13.5-square kilometer watershed on Chichagof island in southeast Alaska. Bedload sediment was sampled for 10 storms: peak flows ranged from 0.6 to 19.0 cubic meters per second, and transport rates ranged from 4 to 4400 kilograms per hour. Peak transport rates typically occurred during peak streamflow. Transport of bedload sediment at a riffle over 1600 meters upstream from the mouth of the watershed was greater for most storm events than that measured...