Abstract:

All 90 sample trees of Liquidambar formosana were obtained in 10 diameter classes including 40 stem analysis,based on the 8th Consecutive Forest Inventory data of the distribution of camphor in Guangdong Province in 2012,the growth models of different site grades of Liquidambar formosana were studied.The results showed that:(1) optimal equations to simulate the growth process of DBH,tree height and volume were of Gompertz,which were as follows:$D=43.100e^{(-3.277e^{-0.067T})},H=19.404e^{(-2.336e^{-0.111T})},V=1.244e^{(-6.992e^{-0.069T})}$.Using Gompertz equations to establish the tree height-age classified model and determine the site classification of each tree.The optimal models of DBH were as follows:$D_1=61.724(1-e^{-0.049T} )^{1.915},D_2=51.992/(1+12.946e^{-0.088T}),D_3=36.135e^{(-3.090e^{-0.060T})}$.The optimal models of tree height were as follows:$H_1=26.704e^{(-1.997e^{-0.099T})},H_2=20.035e^{(-2.234e^{-0.099T})},H_3=15.031e^{(-2.471e{-0.099T})}$.The optimal models of volume were as follows:$V_1=3.335(1-e^{-0.044T} )^{3.798},V_2=1.629e^{(-7.434e^{-0.060T})},V_3=1.087/(1+163.827e^{-0.127T})$.(3) The optimal model of classified and unclassified method is different,the fitting models of using classified method in DBH,tree height,volume were better than unclassified model.

Key words: graded height-age model, stem analysis, growth model, Liquidambar formosana, Guangdong