A fractal approach to computer-analytical modelling of tree crowns

In this paper we discuss three approaches to the modelling of tree crown development. These approaches are experimental (i.e. regressive), theoretical (i.e. analytical) and computer-simulational [by L(indenmayer)-system] modelling. The common assumption of these approaches is that a tree may be regarded as a fractal object, being a collection of self-similar objects that combines properties of two- and three-dimensional bodies. We show that a fractal measure of crown can be used as the link between the mathematical models of crown growth and light propagation through the canopy. The approach using the Lindenmayer computer system allows crown development to be visualized and the model to be calibrated according to experimental data. Different stages of the above-mentioned approaches are described. The experimental data for spruce, the description of the computer system for modelling and a variant computer model are presented.