Treesearch

This paper presents the results of ground measurements of logging residue weights and volumes on 30 clearcut units in Douglas-fir forests of western Oregon and Washington. Additional information is given on quantities of material left as slash which might be utilized. These measurements were made on public lands, using a method developed in Canada.

A 26-year-old Tsuga heterophylla stand on the Oregon coast had a total biomass and current net annual production of 231.1 and 36.2 metric tons per hectare, respectively.

Calculated values of precipitation effectiveness index and temperature efficiency index for 48 weather observation stations on the Alaska mainland are used to delineate areas that have different climatic subclassifications during the wildfire season of April through September. The paper outlines procedures, provides maps showing step- by- step analysis along with the resulting areal boundaries, and suggests possible uses of the information.

Four techniques for inventorying manmade impacts along roadway corridors were devised and compared. Ground surveillance and ground photography techniques recorded impacts within the corridor visible from the road. Techniques on large- and small-scale aerial photography recorded impacts within a more complete corridor that included areas screened from the road by vegetation. Techniques were compared on the basis of type and quality of data obtained, types of maps produced, area covered, and relative cost and time requirements.

The latest inventory of the forest resources in the Puget Sound area shows a total of 3,300,000 acres of commercial forest land and 74,859 million board feet (International 1/4-inch scale) of sawtimber volume. Since 1953, about 221,000 acres of commercial forest land have been converted to roads, powerlines, reservoirs, agriculture, and urban and industrial developments, and about 65,000 acres have been set aside in parks and other reserved areas. Total sawtimber volume has decreased about 8 percent; softwoods have decreased 11 percent, while hardwoods have increased 71 percent.

Growth responses to application of all combinations of N, P, and S on four forest and three grassland soils showed that a significant N-S interaction existed for all seven soils. For two grassland soils, a significant response to phosphorus was obtained in combination with nitrogen and sulfur. The volcanic-ash-derived soils and the Klicker soil had the highest potential yield responses to fertilization. Fertilization programs involved with soils which have chemical properties similar to these studied should consider only fertilizer sources which contain both N and S in all cases, and N, S,...

This study of response to partial cutting over a 17-year period in a 96-year-old stand of western hemlock-Sitka spruce at Karta Bay, Alaska, showed that crop trees left after partial cutting were able to increase or maintain &out the same rate of diameter growth as before thinning, but growth in diameter of trees in an unthinned stand followed the norma2 pattern of decline. Opening the stand stimulated epicormic branching, thus reducing quality of trees in the future. Partially cut plots became well stocked with conifer regeneration, mostly western hemlock.

Vigorous, mature (post-rotation age) Douglas-fir stands will probably exist for another 50 years or more on some properties in western Oregon and Washington. Intermediate harvests in the form of thinnings were analyzed on nine study areas ranging from 70 to 150 years old when thinned. Recoverable cubic-volume growth, averaging 81 percent of normal gross growth, was recorded for up to 38 years with single thinnings and for 18 years with two thinnings. This percentage increases with stand age, but rate of response to thinning decreases with increasing stand age. A dramatic 61-percent...

Hard fescue survival rates were followed for 6 years on four different pine needle treatment plots. Needle litter had a significant effect on initial survival of fescue seedlings, but subsequent losses undoubtedly resulted from the interaction of many factors.

An electronic circuit and device designed to eliminate sane of the problems encountered with event recorders in field operations is described.