Studies on Growth Rhythm of 32a Cinnamomum burmanni

By the stem analysis method, the growth rhythm of 32yearold Cinnamomum burmanni plantation in Guangxi Weidu forest farms was analyzed. Base on the data of tree height, DBH, total volume growth and stand age, we established regressive equation and determined the optimum growth model. The results showed that the tree height, DBH and volume of the 32yearold Cinnamomum burmanni were 17.6 m, 32.55 cm and 0.539 m3, respectively. The annual increment of tree height was increase gradually in the first 6 years, and then reached the peak in the 6th year, which was 090m/a. After that, tree height gradually decreased with age. Also, DBH growth have the similar change rule, in which annual increment of DBH reached the peak in the 4th year, with the value of 2.42 cm/a. What′s more, the annual increment of volume was increase first and then declining with age, the growth peak of which appeared in 22year, with the value of 0035m3/a. The annual growth curve and average growth curve intersected in 32year, thus we could determine the age of volume mature was 32 years. After fitting by growth regularities regression equation, we found that, among the regression models of tree height, DBH and forest age, Richard model was optimal, and SuMaKe model was optimal for volume, fitting correlation coefficient R2 were all above 0.997, the sum of squared residuals was lesser, growth prediction model has higher accuracy.