Precommercial thinning intensity in longleaf pine: effect on product volume and value

Abstract

The possible benefit of precommercial thinning in longleaf pine was evaluated from a spacing study initiated in 1967 on the Escambia Experimental Forest in Brewton, AL. The study was established in dense, naturally established, seedling stands 9 years from seed. Plots were thinned to densities of 300, 600, 900, 1200, and 1500 trees/acre. Later, the initial range of densities was maintained by periodic-thinning to target basal areas of 30, 60, 90, 126, and 150 ft²/acre. In 1993, plots were installed in unthinned areas of the stand to provide a comparison of volume yields between thinned and unthinned plots. Merchantable pines (3.5inches DBH) on each plot were evaluated and placed into one of four product classes: poles, sawlogs, chip and saw, or pulpwood. Precommercial thinning to any of the 5 residual densities did not significantly improve either pine volume or yield over unthinned stands by age 34, even though unthinned stands carried more than 15 f&acre of hardwood basal area that was absent from thinned stands. These plots were re-measured in August 1998 to provide an update to the 1993 data.

Citation

Kush, John S.; Boyer, William D.; Meldahl, Ralph S.; Ward, George A. 1998. Precommercial thinning intensity in longleaf pine: effect on product volume and value. In: Proceedings of the 2^nd Charleston, Longleaf Alliance Conference; 1998 November 17-19; SC. Longleaf Alliance Report No. 4. Auburn University, AL; Longleaf Alliance: 106-108.