Abstract:

The modeling and evaluation methods of stand form height were studied in order to establish the stand form height models suitable for different stand types in key state-owned forest areas in Heilongjiang Province.Based on the data from 9974 sample plots,17 stand types were formed by classification,8 functions which covered all common stand form height models were selected for fitting,and the optimal models were determined by maximizing the adjusted coefficient determination (Ra²)and minimizing the standard error of estimate (SEE).Four essential evaluation indices including the total relative error (TRE),the mean systematic error (MSE),the mean prediction errors (MPE)and the mean percent standard errors (MPSE)were used to cross-verify the optimal models.Optimal models for 32 sub-regions were established.The further regression analysis showed that the TRE and the MSE were within ±0.1%,the MPE was less than 3% and the MPSE was less than 12%.The representative stand form height model system of Heilongjiang key state-owned forest region was formed.These results showed that the established optimal models had good compatibility with the corresponding sample plots,and the models had good predictability.This study made up for the vacancy of stand form height modeling in Heilongjiang key state-owned forest region,which had the value of popularization and could be applied in the forest managementinventory and in the continuous forest inventory.It was further verified that the method of model fitting by using all sample data and model verification by using jack-knife method was feasible.

Key words: stand form height, Heilongjiang Province, key state-owned forest regions, evaluation indices, applicable model