Stand Biomass And Stand Carbon Storage Estimation Model Of Pinus Koraiensis Plantation Forest In Heilongjiang Province

Currently,regional scale estimation of forest biomass and carbon storage is the focus of researchers.It is a method to estimate the biomass and carbon storage of forest layer by developing the biomass and carbon reserve models of stand level.The data of this paper based on the forestry inventory of Korean pine plantations of Heilongjiang Province.The stand variable-biomass model,stand volume-biomass model,both stand volume and biomass expansion and conversion factors(BCEFs)-biomass model,stand variable-carbon storage model,stand volume-carbon storage model,both stand volume and carbon storage expansion and conversion factors(CCEFs)-carbon storage model were developed by using the aggregation method,proportional weighting of one-step method,and the disaggregation method.And each model based on the proportional weighting of one-step approach uses the least squares method(OLS)for parameter estimation.Weighted functions were used to eliminate the effect of heteroscedasticity on the parameter estimation of each model.The leave-one-out cross validation(LOOCV)was used to validation the forest biomass and carbon storage models.The fitting results of three types of stand biomass models and stand carbon storage models based on three additive methods were evaluated by the determination coefficient(R2)and root mean square error(RMSE).The validation results were evaluated by determining the mean absolute value(MAB),the relative absolute value(MPB),and the mean error percentage(E%).The results showed that there is no consistency among the three additive methods in the prediction accuracy ranking of different biomass and carbon storage models.The difference between the three additive methods is very small,except in the model of stand volume-biomass and carbon storage.The corresponding model with the best performance of additive method among all biomass and carbon storage models was also selected,and the comparative analysis results were:both stand volume and biomass expansion and conversion factors(BCEFs)based on the aggregation approach-additive biomass model(system 3)>stand variable based on proportional weighting of one-step approach-additive biomass model(system 1)>Stand volume based on the disaggregation approach-additive biomass model(System 2),both stand volume and carbon storage expansion and conversion factors(CCEFs)based on the aggregation approach-additive carbon storage model(System 6)>stand variable based on proportional weighting of one-step approach-additive carbon storage model(System 4)>Stand volume based on the disaggregation approach-additive carbon storage model(System 5).Three types of stand biomass and stand carbon storage models based on three additive methods were constructed in this study.The both stand volume and biomass expansion and conversion factors(BCEFs)based on the aggregation approach-biomass model and the both stand volume and carbon storage expansion and conversion factors(CCEFs)based on the aggregation approach-carbon storage model had the highest prediction accuracy,which is suitable for estimating the biomass and carbon storage of Korean pine plantation in Heilongjiang Province,respectively.