A comparison of yield estimation techniques for old-field loblolly pine plantations

Efficient management of loblolly pine (Pinus taeda) plantations requires accurate estimation of stand yield at rotation. Methods of estimating yield from stand variables, existing number of trees per acre, height of the dominant and co-dominant stand, and stand age, are presented. These methods include a multiple regression model for estimating stand yield directly from stand variables, and indirect approaches for first approximating the frequency distribution of tree diameters, and then estimating stand yield from individual tree volume equations and the approximate diameter distribution. The accuracy and precision of the stand yield estimates and the diameter distribution approximations were compared. The age at which mean annual increment culminated for various combinations of stand variables was also compared. A new stochastic model for individual tree and stand growth and yield was presented. This model was based on the physiological processes which result in tree growth. Data required to fully develop this model were not available. Recommendations as to which methods should be used to estimate yields and approximate diameter distributions were made.