Basal-area projection equations for thinned natural even-aged forest stands

Abstract

Several existing basal-area projection equations, including one with a thinning term, were compared by using data from a long-term thinning study in natural even-aged stands of loblolly (Pinustaeda L.) and shortleaf pine (Pinusechinata Mill.) in the West Gulf Coastal Plain. The model with the thinning term was no better than existing models with no thinning variable. These results prompted a search to improve the projection models that include thinning. A general technique for introducing a thinning variable into basal-area projection models was developed. This study found that the efficacy of adding a thinning term depends upon the accuracy requirements of the user.