In the late 1950's and early 1960's, a series of studies was installed in the central hardwood forest to determine if size of clearcut opening affects the growth rate and species composition of new stands. In 1991, about 30 years after cutting, stand data were collected in 89 openings ranging in size from 0.04 to 1.61 acres. Species composition varied from locations in West Virginia to those in Illinois and from Ohio to Kentucky. For example, there were more maple and birch in West Virginia than in Illinois, regardless of opening size. Some of the difference in species composition and growth rate is related to site quality but there also are differences due to size of opening. Most of the oak and hickory were on the poorer sites while yellow-poplar was more abundant on the better sites. The number of stems per acre increased with opening size; however, the number of stems of shade-tolerant species constituted a greater proportion of the stand in small openings (< 0.5 acre), while the proportion of intolerant species increased in larger openings. Basal area and volume of the current stands seem to increase markedly with opening size for openings up to at least an acre. The greatest reduction in growth is nearest the border of the opening, though some effect on growth extends at least 100 feet into the opening. There also is a strong interaction between border effect and opening size. Productivity is greater at a given distance from the border for larger openings. Opening size has a major influence on stand characteristics after about 30 years.
Precommercial thinnings were repeated four times in a central hardwood sapling stand beginning at age 8 and ending at age 22. Treated plots were thinned on an areawide basis to specified density levels of 30-, 50-, and 70-percent stocking. The species composition of all stems in the stand was altered somewhat by thinning, but similar trends occurred on control plots. The species composition, growth, and quality of potential crop trees were not improved substantially by thinning. Results indicate that repeated areawide precommercial thinnings to specified density levels is not an effective timber management alternative for hardwood sapling stands.
Updated tree value conversion standards (TVCS) are presented for 12 major hardwood species of the central hardwood forest. TVCS measure a tree's worth in dollars based on the quantity and quality of its expected yield of 414 (I-inch) lumber. The updated standards-developed for each species by butt-log grade, merchantable height, and diameter at breast height-reflect the changes in lumber prices and in conversion costs which have occurred since 1976 when the original TVCS were published.
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