Early diameter growth of trees in planted forest stands

A model to describe early diameter growth of trees in planted forest stands is presented. Relative diameter growth rate of free-grown trees is used to estimate potential diameter growth of competitively grown trees of the same species and age. The effect of competition on the ability of competitively grown trees to attain their growth potential is assumed to be a function of site resource availability—growing space. Data from free-grown trees of the correlated curve trend projects in South Africa are used to estimate growth at several spacings at other South African sites and in Hawaii. The model produces typical current annual and mean annual growth curves as well as branched curves of diameter growth over time at different spacings. It is consistent mathematically with relative density concepts. Because individual tree diameter and stand volume are the most important factors in harvesting costs, the model can serve as a decision support tool to assist forest plantation managers choose how many trees to plant per unit area for optimum cost-efficiency in short-rotation intensive-culture operations.