A Dynamic Prediction of The Diameter Structure of Pinus yunnanensis Stands

The study was conducted on the permanent sample plots of Pinus yunnanensis.According to the growth conditon of the trees,the individual trees were divided into 4 categories i.e.dying,stagnating,a diameter growth of 1 cm/year,and a diameter growth of 2 cm/year.The mean diameter deviation index and density index were used for modelling the diameter distribution.Simulation of the diameter distribution of P.yunnanensis were carried out by means of the model.The results indicate that the predicting model has a high accuracy.This study provides a new modelling technique in the fields of predicting diameter distribution.