Timing of Longleaf Pine Seedling Release from Overtopping Hardwoods: A Look 30 Years Later

Abstract

Abstract Significant differences in longleaf pine (Pinus palustris) growth among early and delayed seedling release treatments were recorded at age 10, but these differences had disappeared upon reexamination at age 31. A study begun in 1949 included six release treatments: complete seedling release from overtopping hardwoods at ages 1, 2, 3, 4, and 8 years, plus an unreleased check. Treatments were randomly applied among six 0.1-acre plots in each of six blocks, which included both poor and average sites. Seedling development was observed through age 10. When pines in five surviving blocks (two poor site, three average site) were remeasured in 1979 at age 31, there were no significant differences among release treatments in average tree heights and diameters or stand basal areas and volumes. The check treatment had significantly lower tree heights, stand densities, and stand volumes than any release treatment.