Study on the growth rhythm of 23-year-old Castanopsis fissa plantation

This paper studied the growth rhythm of 23-year-old Castanopsis fissa plantation in Haiming forest farm(Pingguo county,Baise city,Guangxi province) by stem analysis method.The results were as follows: The average DBH,tree height and volume of the 23year-old Castanopsis fissa plantation were 19.4 cm,20.4 m,0.3261 m3.The fast growing period of diameter,tree height and volume were 2~8 years,6~11 years,6~23 years.Current annual increment curve and average increment curve of volume didn't intersect in 23 years.It showed that 23-year-old Castanopsis fissais plantation had not reached the quantitive mature age.The growth equations of diameter,tree height and volume were D=1.7133T-0.0506T2+0.0007T3-1.9422,H=1.9257T-0.0398T2-2.4890,V=-0.0104T-0.0024T2-4.0848e-0.005T3+ 0.0127.According to the volume regression equation of Castanopsis fissa,its mature age was considered at 24 years old.