Shoot-based three-dimensional model of young Scots pine growth

The aim of the research was to create an algorithm simulating height-diameter relations in a pine tree subjected to various environmental impacts. The model is based on explicit description of light competition of the Scots pine twigs in three-dimensional space. The model is empirical and results from the measurements of correlations between shoots and buds in Scots pine that were made in the field. The development of the root system is not considered by the model. ulation experiments it was demonstrated that: (i) the stand-grown pines have a higher height/diameter ratio than an open-grown model tree; (ii) an extremely high height/diameter ratio leads the tree to death; (iii) a tree suppressed for a sufficiently long time does not respond to better conditions; (iv) the diameter growth is much more sensitive to environmental change than the height growth. The model trees had the same growth parameters in every simulation. The simulated growth reactions are accounted for by self-adjustments of the model structure to the imposed conditions.