Basal area development in thinned and unthinned loblolly pine plantations

The purpose of this study was to investigate basal area growth in loblolly pine (Pinus taeda L.) stands after thinning and develop a generalized equation suitable for projecting stand basal area development for a range of thinning treatments, site conditions, and stand ages at time of thinning. The data available came from the Loblolly Pine Growth and Yield Research Cooperative's region-wide thinning study and cover a wide variety of stand conditions. The results of the study indicate that the basal area of the thinned stands approaches that of their unthinned counterparts. Based on these findings we developed a basal area projection equation that includes a thinning response factor and accounts for the effects of competing hardwood vegetation. Model Validation demonstrated that ignoring the differences in the thinning response leads to biased basal area predictions, while including the thinning response factor resulted in precise basal area projections for the thinning treatments applied to these plantations.