Because of natural mortality on unthinned control plots, pines in the dominant and codominant crown positions were well-spaced as a result of natural selection and such spacing contributed to impressive growth rates and the second highest PNV at 20 years. Thinning should leave from 500 to 750 stems per acre to maximize diameter growth. After precommercial thinning, prescribed burning is not recommended until the pines have achieved crown closure. If a landowner decides to forego the cost of precommercial thinning in a dense even-aged stand of natural pines, then commercial thinning should be done as soon as merchantable volumes exceed the minimum operational cut while retaining the better trees for sawlog production. Without thinning, pines in dense stands are at high risk to loss by natural destructive agents such as southern pine beetle infestations.
Modern technology can improve strategy for thinning timber.
Grano, C.X. 1969. Precommercial thinning of loblolly pine. Mann, W.F., Jr., and R.E. Lohrey. Precommercial thinning of southern pines. Williams, R.A. 1974.