A METHOD FOR PREDICTING TREE DIMENSIONS IN SCOTS PINE AND NORWAY SPRUCE STANDS

The study Presents a simultaneous equation model for predicting tree diameter, height, and breast height age in a stand with a specified spatial pattern of tree locations. The exogenous predictors are stand age, dominant height, stand basal area, number of trees per hectare, and a competition index computed from the distances to and diameters of the neighbouring trees. Using the models and a birth-and-death technique, it is possible to simulate tree stands in which variation in tree parameters is connected to the variation in stand density. That part of the variation in tree parameters which is not accounted for by the exogenous variables, is simulated using random numbers drawn from the three-dimensional multinormal distribution of the estimation errors of the model set.