Study on growth rhythm of Acrocarpus fraxinifolius plantation

The growth rythem of 36-year-old Acrocarpus fraxinifolius in central Guangxi was studied by method of stem analysis.The average height,DBH and volume of 36-year-old A.fraxinifolius plantation were 28.73 m,37.37 cm and 1.5128 m3.The growth forecast models of height,DBH and volume all showed a well correlation with the forest age,and the Schumacher model was the optimal growth models for the height and volume,the Korf model was the optimal growth model for the DBH.The model of volume was accurate for estimating the later forest volume.Moreover,the annual growth curves of height and DBH were in a fluctuating growth trend,the maximum average growth of height at 16 years was 1.04 m),the average growth of DBH was kept the biomass growth of 1.01~1.19 cm from the 6th year.The volume growth curve and average growth curve had not yet intersect,the 36-year-old A.fraxinifolius did not reach the age of quantitative maturity.The breast-height form factor of the 36-year-old A.fraxinifolius was 0.47,the current annual growth rate of volume was 5.57%.This tree species shows a well straight form and obvious characteristics of fast-growing,and should be an excellent material for cultivating large diameter timber.