Treesearch

The determination of an optimal sequence of diameter distributions and selection harvests for uneven-aged stand management is formulated as a discrete-time optimal-control problem with bounded control variables and free-terminal point. An efficient programming technique utilizing gradients provides solutions that are stable and interpretable on the basis of economic principles. Methods and results are demonstrated using a whole-stand/diameter-class simulator developed for northern hardwoods stands in Wisconsin. Examples in which the objective is present net worth maximization over a...

Numerical techniques have been used to compute the discrete-time sequence of residual diameter distributions that maximize the present net worth (PNW) of harvestable volume from an uneven-aged stand. Results contradicted optimal steady-state diameter distributions determined with static analysis. In this paper, optimality conditions for solutions to dynamic and static harvesting problems are established. Comparison of these conditions shows that for a stand with any diameter distribution: (1) the optimal transition regime does not converge to the steady state that maximizes land expectation...

This annual assessment of the pulpwood production and receipts for the 14 states in the Northeast Region shows that in 1983 total production reached 8,673,800 cords. This was up 3 percent (221,600 cords) from 1982. The roundwood portion increased by less than 1 percent to 6,330,000 cords, whereas the residue portion rose by 10 percent to 2,343,800 cord equivalents. The receipts of pulpwood at the 42 mills in the region set a new high of 9,253,700 cords consumed. This report is based on a canvass of all pulpmills that use roundwood or wood residue from the Northeast as a basic raw material...

Number-of-trees data compiled by the USDA Forest Service from three periodic statewide inventories of Maine's forest resources are used to analyze the composition of the state's timberland in terms of species, tree class, and size. Conditions are compared and contrasted for periods from 1959 to 1971 to 1982 across different regions and counties of the state. Twenty-three statistical tables containing 1982 estimates of number of trees, trees per acre, and average diameter are presented.

In 1983 Wisconsin''s forests covered 15.3 million acres, an increase of 2.7 percent from the 14.9 million acres reported in 1968.

Lake States pulpwood production climbed to a record 7.19 million cords in 1984. Pulpwood production is shown by county and species group in Michigan, Minnesota, and Wisconsin.

Hundred-seed weights from 15 trees in each stand averaged 330 mg; 100-seed weights differed significantly among trees within stands and among stands. Germination of filled seed averaged 95 percent; germination differed significantly among trees within stands, but not among stands. Detailed seed records should be kept for all seed orchards.

Describes a testing procedure used to calibrate and evaluate agricultureal boomless spray systems. Tests allow the user to obtain dependable and satisfactory results when used in actual forest situations.

Summarizes information about white spruce plantations as of 1982. Based on average site index, the Superior National Forest in Minnesota and the Hiawatha and Huron-Manistee in Michigan contain climate-soil-seed source complexes that are, on the average, less productive for white spruce than on the other National Forests

Young Jack pine exposed to water stress produced several times more female strobili than trees watered regularly. The timing and duration of the treatments was important.