A Site Growth Model for <i>Pinus pinaster</i> in the Southern Cape
Abstract
SYNOPSIS Knowledge of site productivity of forest land is a basic requirement for sound forest management. Predictive growth models were developed for P. pinaster in the Outeniqua foothills of the Southern Cape. Ninety plots were demarcated and over 50 variables were used in the analyses. The models use soil depth, radiation index and exchangeable aluminium. Effective soil depth which reflects soil moisture availability was the most useful parameter for prediction of tree growth performance. Where the average effective soil depth is less than 250 mm a mean annual increment at 20 years of less than 4 m3/ha per annum can be expected, which is an uneconomical proposition for forest management.