In order to understand the effect of planting density on the growth model of Betula alnoides plantation,analytical trees were used to analyze its growth dynamics,to enrich the information related to plantation and provide the scientific basis for cultivation management.In Jiangcheng County,Pu'er City,Yunnan Province,based on the investigation for a 21-year-old B.alnoides plantation of established by different initial uneven row spacing(2 m×2 m×5 m,2 m×3 m×5 m,3 m×3 m×5 m and 2 m×2 m×10 m),the best growth models of the trees with different planting densities was analyzed based upon the 12 standard trees selected from each tree measure.The results showed that mean diameters at the breast height(DBHs)under bark,tree heights(THs)and timber volume under bark of the different planting densities for the 21-year-old stand trees were 16.8~17.5 cm,26.7~28.0 m and 0.274 3~0.333 8 m3,respectively,and the trees were still in vigorous growth stage.The peak growth differentiation of DBHs,THs,and timber volume at different planting densities was observed during 9~12,9~11 and 8~15-year-old,respectively,when the planting densities had significant (P=0.025~0.046<0.05,P=0.001~0.006<0.01) effect on the total volume increment.The best fitting predictive models for DBHs,THs and timber volume-ages of the different planting densities were generally dominated by the Richards model and Gompertz model,in which Richards model can be used for the growth analysis and prediction of DBHs,THs,and timber volume of B.alnoides plantation.
