Silvicultural factors affecting sawlog quality of loblolly pine
A series of 47 uncut, ¼-acre plots of insect- and disease-free even-aged pure loblolly pine in Georgia, South Carolina, and Virginia were selected for use in assessing the effects of age, site index, and density on sawlog quality. Plot ages ranged from 25 to 93 years, site indices from 52 to 104 feet, and stand densities from 102 to 179 square feet of basal area per acre of stems 0.6 d.b.h. and larger. The index of sawlog quality was "K"/MBF where "K" equals the number of overgrown knots, plus the sum of diameters of sound exposed knots, plus twice the sum of diameters of unsound knots. The best fit of 2 stepwise regression analysis resulted in the following equation: Log "K"-count/MBF = 3.313940 - .013522(Age) - .000185 (Age X Site) Approximately 89 percent of the variation about the mean was accounted for by this expression.