Predicting stand basal area in thinned stands using a dynamical model

When a forest stand is thinned, its growth characteristics change. Forest a nalysts who model growth are then faced with the challenge of developing mo dels that can predict stand growth in the post-thinned period, regardless o f the particular thinning regime. Using Pinus patula Schl. et Cham., data f rom the Nelshoogte (South Africa) thinning experiment, a novel dynamical mo del describing stand basal area growth was developed. The model has the for m of a first-order difference equation with coefficients that are dependent on stand density. The model is compared against previously published basal area models (developed from the same data as the dynamical model). It is c oncluded that the dynamical modeling structure offers superior flexibility and accuracy in predicting stand basal area response in the post-thinning p eriod. (C) 1999 Elsevier Science B.V. All rights reserved.