Treesearch

During the 1966 - June 30, 1967 fiscal year, calibration work on the stream ecology phase of the project continued along about the lines of last year's work. The emphasis was on determining the importance of stream canopy, particulary as it affects the amount of solar radiation being received at the water surface and on stream conditions influenced by the amount of radiation.

The total potential market for flooring, siding, and cabinet and millwork in new single-family houses on Oahu was between 10½ and 11 million board feet of lumber in 1963. The total possible market for lumber in new single-family house construction from 1965 to 1970 is estimated at 18 to 23 million square feet of floor-ing, 28 to 36 million square feet of siding, and 7 to 9½ million square feet in cabinets.

Describes an expansible computerized system that provides data needed in regression or covariance analysis of as many as 50 variables, 8 of which may be dependent. Alternatively, it can screen variously generated combinations of independent variables to find the regression with the smallest mean-squared-residual, which will be fitted if desired. The user can easily program additional processing.

An analytical and simulation technique, parametric linear programing explores alternative conditions and devises an optimal management plan for each condition. Its application in solving policy-decision problems in the management of forest lands is illustrated in an example.

A "bench-top" calorimeter was constructed to determine the radiation-convection partition of energy released in the burning of fuel. Samples of 1 to 2 g, no larger than 4 cm in horizontal dimension, and with flame height less than 15 cm, can be accommodated. The apparatus functions by (1) absorbing radiant energy from the burning fuel in an insulated thin aluminum shell whose temperature rise is recorded by a series of imbedded thermocouples, and (2) measuring convective energy by recording the electric power required to heat an air stream so that it just balances the flow rate and...

When samples undergo a complicated set of simultaneous and sequential reactions, as cellulose does on heating, results of thermogravimetric and differential thermal analyses are difficult to interpret. Nevertheless, careful comparison of pure and contaminated samples, pyrolyzed under identical conditions, can yield useful information. In these experiments TGA and DTA curves were obtained, in air and in an inert atmosphere (nitrogen). with "ash-free" cellulose (ash content <0.01%), "pure" cellulose (ash content ~0.15%), and "treated" cellulose (1.5% KHCO3, added). The results show that as...

To approximate a group selection cut at the Challenge Experimental Forest, 48 small openings of three sizes—30, 60, and 90 feet in diameter—were logged in 1963. One aim was to create conditions of light and soil moisture that would favor establishment and growth of Douglas-fir, sugar pine, and white fir over ponderosa pine. Seed fall and first-year regeneration were comparable within the three openings for the three species.

At the Challenge Experimental Forest, 29 acres of slash were broadcast burned on five small clearcut plots (2 to 10 acres) at a cost of $57.00 per acre. Fuel-weight measurements showed reductions of 68 to 84 percent after the burn. Modifications to plot size, shape, and orientation could reduce this cost.

Foresters sometimes must estimate the timber volume that recently existed on cutover forest land. This may be necessary, for example, if a stand killed by fire was salvage logged before an inventory of killed timber could be made; or in cases where the timber was cut and removed by a trespasser. Usual procedure in these situations is to cruise the tract, taking diameter inside-bark (d.i.b.) measurements on stumps. Then tree diameter breast high (d.b.h.) is estimated using the rule-of-thumb that "d.b.h. equals stump d.i.b." Finally, given an estimate of d.b.h., tree volume is obtained from...