Abstract: Based on average sample tree determination and branch analysis method,the mean branch method and single branch biomass model were used to estimate the crown leaf biomass,branch biomass of Larix olgensis forest in Dongzhelenghe station.Analysis was made on the relationships between single branch base diameter and branch length,between single branch biomass and branch base diameter,branch length and the related factors,establish branch length model and branch biomass model respectively.By comparing the different estimating model of branch biomass,the results show that the branch base diameter was highly correlated to branch biomass and branch leaf biomass,the power function is fitting best,the accuracy is higher and the estimating parameters are more stable although the coefficients of quadratic function are larger,which causes larger fluctuation of parameters and unstable prediction.In this study,based on diameter at breast height, different allometric equations of the crown biomass are established and the coefficient(R²) of crown biomass model are more than 0.906.Through the comparison of method of estimating crown biomass,the results show that branch biomass model method is better than mean branch method,and F test is used for test of models,the F values are at a significant level.The branch biomass models for estimating Larix olgensis crown biomass are of certain reference value.

Key words: biomass, allometry, Larix olgensis Henry, branches, crown