Treesearch

The USDA Forest Service now estimates biomass during periodic resource inventories. Such biomass estimates quantify more of the forest resource than do traditional volume inventories that concentrate on tree boles. More than 48 percent of the aboveground tree biomass in the northern United States can be found in woody material outside of the boles. Tree biomass in the Northeastern and North Central regions of the United States is compared by state.

The incidence of nondiapause in artificially reared red oak borers increased from 4 to 61 percent in five generations. Fecundity dropped by more than 50 percent, but fertility was unaffected. Sixty percent of the nondiapausing larvae formed prepupa by the 12th week of development in the F1 and in the F4 generations.

The biomass of 50-year-old cove hardwood and upland oak stands on an Appalachian watershed was more strongly related to basal area than to site index. Equations are presented for predicting the green and dry weight per acre of biomass components with basal area as the independent variable.

Field studies demonstrated that migrating larval instars of the gypsy moth, Lymantria dispar (L.), preferred resting locations placed on tree boles at 4.6 m over those placed at 1.5 and 3 m. More larvae were found beneath bark flaps than beneath flaps of hard black plastic.

Describes the development of multivariate equations that predict the expected cubic volume of four round-product classes from independent variables composed of individual tree-quality characteristics. Although the model has limited application at this time, it does demonstrate the feasibility of partitioning total tree cubic volume into round-product classes based on tree-quality characteristics.

A detailed organic soil profile description, 22 years of continuous water table records, and a hummock-hollow level survey were examined at a small Minnesota mire (a bog with remnants of poor fen vegetation). Variation in the level survey suggests that hollows be used to minimize variation when detailed topographic information is needed and to match profile descriptions from distant locations. Water table and profile information suggests modification of acrotelm and catotelm definitions to recognize drought conditions and a field-identifiable boundary between the two layers.

Three System 6 mill-size alternatives were designed and evaluated to determine their overall economic potential for producing standard-size hardwood blanks. Internal rates of return ranged from about 15 to 35 percent after taxes. Cost per square foot of blanks ranged from about $0.88 to $1.19, depending on mill size and the amount of new investment required.

A crown-touching release of 12-year-old black cherry and yellow-poplar crop trees on a good site required removing an average of 14 trees for every crop tree. An average of 80 crop trees per acre was left free-to-grow with an average growing space of 4.7 feet on all sides of the crown. Basal spraying cost $0.80 per crop tree, stem injecting cost $0.61 per crop tree, and chain saw felling cost $0.42 per crop tree. Recommendations on release methods and suggestions for cost savings are provided.

Presents equations to predict diameter at breast height from stump diameter measurements for 17 northeastern tree species. Simple linear regression was used to develop the equations. Application of the equations is discussed.

Kentucky 31 tall fescue and sericea lespedeza were sown on clay and loam minesoils that had been screened throu h a No. 10 sieve and compacted to densities of 1.6, 1.8, and 2.0 gfjcm3. Stands of sericea lespedeza were more difficult to establish than fescue on both minesoils and were more susceptible than fescue to increased levels of compaction. Dry matter yields averaged over all densities were greater on the clay than on the loan minesoil.