Abstract:

Based on the data of permanent plots measured in 2001,2006,2011,2016 in Hebei province from the 6 ^th to 9 ^th national forest inventories of China,tree-level dbh(diameter at breast height)growth rate and volume growth rate models for 18 tree species and stand-level volume growth rate models for 12 tree species group were developed using nonlinear regression method.The results show that the MPEs(mean prediction errors)of the tree-level models are almost less than 3%,and the MPSEs(mean percent standard errors)are almost less than 10% for dbh growth rate models and less than 20% for volume growth rate models.For stand-level volume growth rate models,the MPEs are almost less than 5%,and the MPSEs are almost less than 25%.The models developed in this study can provide technical basis for implementing annual updating of forest resource data in Hebei province.

Key words: growth rate of diameter, growth rate of volume, tree-level model, stand-level model, Hebei