L-system-based model of growth of dark coniferous tree species

On the basis of L-systems a mathematical model was designed to describe the growth of a dark coniferous tree. The software models a virtual timber stand composed of single trees and its further development. To eliminate branch crossing of growing trees, the rule forbidding shoot growth into the space already occupied was applied to the model. The model parameters were defined for two dark coniferous species of the southern Sikhote-Alin’ — Jezo spruce (Picea jezoensis) and Khingam fir (Abies nephrolepis). The model describes various modifications of tree crown under the influence of neighbouring trees, height uncertainty of crown starting point, variation of taper and shape of a trunk depending on plantation density, and recovery of normal tree growth after singling. Comparison of the modelled results and empirical observations show that the model succeeds in describing the growth both of single trees and of mixed plantations.