Change in Radiation Conditions of Middle-Aged Pine Forest Subsequent to Thinning

1989

S. 134-146

4 Abb., 4 Tab., 7 Lit. Ang.

Unselbständiges Werk

200056123

The article presents a computer model for describing radiation conditions of stands. The model enables to determine the average diffuse radiation conditions of a stand at any given point and of the stand layer at any given height. The results of calculations concern two different periods prior and subsequent to thinning. The dimensions of the trees and their horizontal coordinates in a study area serve as input parameters to the model. Model calculations of the effect of thinning indicate that relative improvement of radiation conditions of the remaining trees is considerably less than the respective relative parameters of thinning. For example, when 24% stand volume, i.e. 39% of the number of trees or 16% of the stand needle biomass, was thinned, the improvement achieved in the radiation conditions of the remaining trees was 1% at the top, 5% at the centre of the crown and 9% at the beginning of the crown.