Twelve-year results of a loblolly pine site preparation study in the Piedmont and Upper Coastal Plain of South Carolina, Georgia, and Alabama

摘要

A designed experimental study was installed at 25 separate locations in the Piedmont and Upper Coastal Plain regions of South Carolina, Georgia, and Alabama with the objective of evaluating the effects of different site preparation treatments, both chemical and mechanical, on growth and Yield of cutover site-prepared loblolly, pine (Pinus taeda L.) plantations. The following six site preparation treatments were included: (1) burn, (2) chop and burn, (3) shear, pile and disk, (4) chop, herbicide and burn, (5) herbicide and burn, and (6) herbicide, burn and complete vegetation control. The herbicide, burn and complete vegetation control treatment significantly, increased mean dbh, mean height, stand basal area, and total and merchantable volume compared to all other treatments. The burn-only, treatment consistently ranked worst compared to all other treatments. There were significant differences in mean dbh, mean height, stand basal area, and total and merchantable volume between: (1) the herbicide and burn, which is an operational chemical treatment, and (2) the average of the chop and burn treatment and the shear, pile and disk treatment, which are operational mechanical treatments. in all cases the operational chemical treatment performed significantly better than the average of the two operational mechanical treatments. Average 12-yr-old merchantable volumes (ft(3) lac) across all locations by treatment were: burn (846), chop and burn (1,445), shear, pile and disk (1,740), chop, herbicide and burn (1,669), herbicide and burn (1,919), and herbicide, burn and complete vegetation control (2,546). There were no apparent trends in percent fusiform infection levels across site preparation treatment intensity levels.