A review of site-growth studies in South Africa

The intensive nature of the South African forest industry requires reliable decision support systems to enhance site-specific silviculture. Furthermore, the principle of ecologically sustainable forest management requires a profound improvement in the understanding of the factors controlling tree growth and the limitations of the sites on which they are planted. The lack of quantitative evaluation systems for accurate site-species matching necessitated South African forest researchers to develop site-growth models to initiate the development of plantation decision support systems. The objectives, principles and procedures for developing site-growth models are discussed, together with the main advantages and disadvantages of implementing such models on operational forest management levels. Recommendations for a future strategy in site-growth studies are provided. The simulation of ecological processes influencing tree growth will, in future, receive preference over the use of discrete site variables to predict the growth of trees.