Treesearch

An annual maple syrup production cost series was developed for the period 1972 to 1984. Comparisons were made between plastic tubing and metal bucket technology and wood- and oil-fired evaporation. The effects of sap- sugar content and size of operation were examined together with the relationships among major cost items. The information will be useful to maple syrup producers and lenders needing financial analyses, equipment developers and manufacturers, and public policy analysts and planners.

Component biomass prediction equations are presented for young black spruce (Picea mariana B.S.P. (Mill,:)) in northern Maine. A weighted least squares model was used to construct the eq~iationsfo r small trees from 1 to 15 cm d.b.h., and an ordinary least squares model for trees less than 2 m in height. A linearized allometric model was also tested but was not used. Equations were developed for oven-dry needle, branch, bolewood, bolebark, aboveground, root, and complete tree biomass components. Aboveground components accounted for approximately 80 percent, and stump (less than 6 cm in...

With rapidly increasing lumber prices and shortages of some grades and species, the furniture industry must find ways to use its hardwood lumber resource more efficiently. A computer program called OPTIGRAMI is designed to help managers determine the best lumber to use in producing furniture parts. OPTIGRAMI determines the least-cost grade mix of lumber required to produce a given cutting order of dimension parts. If the optimum grade mix is not available, the program can determine the best alternatives. It also can be useful in procurement and allocation planning. A description of the...

OAKSIM is an individual-tree growth and yield simulator for managed, even-aged, upland oak stands. Growth and yield projections for various thinning alternatives can be made with OAKSIM for a period of up to 50 years. Simulator components include an individual-tree diameter growth model, a mortality model, height prediction equations, bark ratio equations, a taper-based volume system, and a mathematical thinning rule based on actual data. OAKSIM can be applied to a wide range of age, site, and stand conditions to develop management (thinning) guidelines.

A 14-year-old mixed oak stand was thinned in 1977 to stocking levels of 30, 50, and 60 percent and a control. From this stand, 117 trees were selected and their stem-related defects recorded. Six years later these same trees were reevaluated. The number of limb defects per square foot of surface area increased substantially more in the heavily thinned plots than in the unthinned plots. Trends in these data confirm commonly held beliefs that stand density affects stem quality after only a few years.

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development for black cherry. It illustrates and describes seven types of external defect indicators and associated defects that are particularly difficult to evaluate.

Econometric equations were estimated to determine the effects of domestic foreign hardwood lumber demands on oak and hardwood lumber prices. Oak price seemed to be more sensitive to changes in exports than overall hardwood lumber price. However, the main determinants of hardwood lumber and oak lumber prices were found to be domestic demand and millstock levels.

An 18-horsepower skyline yarder was studied on a steep slope clearcut, yarding small hardwood trees uphill for fuelwood. Yarding cycle characteristics sampled include: total cycle time including delays, 5.20 minutes; yarding distance, 208 feet (350 feet maximum); turn volume, 11.6 cubic feet (24 cubic feet maximum); pieces per turn, 2.3. Cost analysis shows yarding costs will range from $18.00 to $36.00 per cunit, depending upon crew efficiency and yarding conditions.

Trampling impact studies were conducted in two eastern forest stands in the White Mountains, New Hampshire. Changes in plant mortality on simulated trails during a trampling period and a recovery period were monitored photographically. The extent of damage and rate of recovery varied among species. For most species, the greatest change in plant mortality occurred between 100 and 300 trampling passes.

Genetic and environmental components of variance for 2-year pot and nursery heights of offspring from inter- and intraprovenance matings in Scotch pine were studied to determine which provenances and selection methods should be used in an ornamental and Christmas tree improvement program. Nursery evaluation was preferred to pot evaluation because heritability estimates were larger and error variances were smaller for the experiments evaluated. Simple recurrent selection would be a good method for improving traits important to the Christmas tree industry.