Treesearch

Bigleaf maple sap flow during the 1970-71 season ranged from none to 16.9 gallons per taphole and sugar content of the sap from 1.0 to 2.6 percent. Sugar content also varied seasonally, with the sweetest sap flowing in late January. The sirup was very flavorful, although not as strong in typical maple flavor as that made from eastern sugar maple. Sirup production appears quite feasible as hobby. The possibility of commercial production should not be ruled out as traditional local experience is gained.

Data from extensive timber inventories of 12 counties in western and central Washington were analyzed to test the relative efficiency of double sampling for stratification as a means of estimating total volume. Photo and field plots, when combined in a stratified sampling design, proved about twice as efficient as simple field sampling. Although some gains were made by stratifying into only two classes—forest and nonforest substantially greater gains accrued when the forest plots were further stratified into timber volume classes. Optimum allocation of field plots was only slightly...

The 1971 Oregon timber harvest of 9.03 billion board feet was the highest since 1969 when 9.15 billion board feet was harvested. The 1971 total harvest was 13.1 percent above the 1970 figure. Western Oregon's harvest rose 11-5 percent, and eastern Oregon's harvest rose 18.6 percent.

The findings of the first complete inventory of the timber resources of Mendocino and Sonoma Counties, California, indicate there is 19.1 billion board feet of sawtimber on 1,564,000 acres of unreserved commercial forest land in these two counties. Forest industries own about 34 percent of the commercial forest area and 37 percent of the timber volume; farm and miscellaneous private ownerships account for 53 percent of the area but only 42 percent of the volume; and public ownerships account for 13 percent of the area and 21 percent of the volume. Almost half the commercial forest area in...

A guide to the use of natural scientific preserves, Research Natural Areas, on Federal lands in Oregon and Washington. Detailed descriptions of physical and biological features, maps and photographs are provided for each of the 45 tracts presently reserved. Indices to Research Natural Areas by vegetation type and plant and mammalian species are included.Supplemental Download

Twelve million tons of residues from lumber and veneer and plywood mills went to pulp and board use in 1968; nearly 88 percent went to domestic mills and most of the remainder to overseas export. Of the 10.3 million tons that went to domestic mills, 83 percent went to pulpmills (average distance 82 miles) and 17 percent to board mills (30 miles); 74 percent was shipped by lumber mills (68 miles) and 26 percent by veneer and plywood mills (88 miles). Fifty percent of residues to domestic mills went by truck (37 miles), 35 percent by rail (147 miles), 6 percent by barge (59 miles), and 9...

Public and private agencies are cooperating in a study of eight thinning regimes in young Douglas-fir stands. Regimes differ in the amount of basal area allowed to accrue in growing stock at each successive thinning. All regimes start with a common level-of-growing-stock which is established by a conditioning thinning. Thinning interval is controlled by height growth of crop trees, and a single type of thinning is prescribed. Nine study areas, each involving three completely random replications of each thinning regime and an unthinned control, have been established in western Oregon and...

The battery-powered recording weather station measures and records wet bulb temperature, dry bulb temperature, wind travel, and rainfall for 31 days. Assembly procedures and cost of supplies and components are discussed.

Detailed operating instructions are described for SIMAC, a computerized forest simulation model which calculates the allowable cut assuming volume regulation for forests with intensively managed stands. A sample problem illustrates the required inputs and expected output. SIMAC is written in FORTRAN IV and runs on a CDC 6400 computer with a SCOPE 3.3 operating system. The conceptual basis of the SIMAC method is not discussed in detail.

Douglas-fir stands first thinned at about age 38 have been observed for 21 years. Four treatments were compared; no thinning, light thinning at 3-year intervals, moderate thinning at 6-year intervals, and heavy thinning at 9-year intervals. Eighteen years after initial thinnings (the first common end to all thinning cycles), all thinned stands had virtually the same total cubic volume as before thinning and about 65 percent of what they would have had without thinning. Early thinnings tended to be from above, later thinnings from below. Thinning interval had no effect on total growth per...