Treesearch

For the western spruce budworm populations studied, day-to-day survival rates were close to constant in the interval from instar IV to residual pupae. In any given crown stratum, host-tree species, and site, day-to-day changes across this interval could be approximated very closely by the Malthusian equation Nt = N0eαt.

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.

Provides current information on the 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.

Provides current information on the 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.

Ratios are presented for estimating volume and characteristics of logging residue in Montana. They relate cubic-foot volume of residue to thousand board feet of timber harvested and to acres harvested. Tables show gross and net volume of residue, with and without bark, by diameter and length classes; by number of pieces per acre; by percent soundness; by product potential; and by degree of slope and distance to roads.

A study established in 83-year-old, even-aged stands of Sitka spruce (Picea sitchensis (Bong.) Carr.) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) at Cascade Head Experimental Forest in the Siuslaw National Forest on the Oregon coast traces their development for 33 years. Statistical data collected from 12 permanent sample plots during four periods of growth illustrate the tremendous productive capacity of the Sitka sprucewestern hemlock type.

A total of 496 logs from lodgepole pine (Pinus contorts Dougl. ex Loud.) trees killed by the mountain pine beetle (Dendroctonus ponderosae Hopk.) were compared with 189 logs from similar live trees. Logs were processed through a stud mill. In most cases lumber recovery from trees dead 1 to 3 years was the same as that from live trees. Less cubic volume was recovered from trees dead 4 or more years. Recovery tables and curves are shown.

The volume and character of woody material on the ground in four old-growth Douglas-fir cutting units in the Cascade Range in Oregon were determined before and after harvesting by cable and yarding of unutilized material (YUM). Total volume of residue increased after logging in all units. Coarse residues were reduced by YUM yarding. Small changes in the defect condition of the timber can drastically affect the amount and character of the residues remaining on the site. Modifying bucking procedures can result in the removal of a considerable volume of usable residue.

The cost of harvesting and recovering round wood logs and whole-tree chips from small diameter lodgepole pine (Pinus contorta) infested by mountain pine beetle (Dendroctonus sp.) was studied in the Blue Mountains of eastern Oregon in 1979. Mechanized harvest operations were conducted on six study sites totaling 134 acres. The average cost of producing chips was $31.30 per ton, wet, delivered 50 miles from harvest sites. The average cost of logs was $50.28 per ton, wet, delivered the same distance. A gross energy balance indicates that energy required by harvesting was about 3.4 percent of...

Replicated forest floor and surface soil (0–15 cm) samples were obtained from control plots at 160 field installations to western Washington and Oregon. Six year growth responses of thinned and unthinned Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in stallations treated with 0, 224, and 448 kg of urea-N ha-1 were correlated with 18 forest floor and surface soil properties of the control plots. Correlations for response with respective forest fl oor and soil data were produced for levels of fertilizer application and both basal area and volume response. Observed and estimated...