Study on Growth Law and Mixed Mode of Pinus massoniana Plantation

The stem analyses were conducted on 33-year-old Pinus massoniana.The results show that the current annual height growth appears the maximum value at the age of 10.The greatest mean growth appears at the age of 10~15 and the first cutting age is about 15.The greatest current annual height growth decrease during the age of 20~25 and the second cutting age is 22.The greatest current annual diameter growth appears at the age of 10,the current annual height growth and average growth meet at the age of 20~25.The greatest current annual volume growth appears at the age of 30,the quantitative maturity age is about 55.The growth and development of 33-year-old Pinus massoniana can be divided into 3 stages,the first stage is the young forest one at the age of 0~10,the second stage is the fast-growing one at the age of 10~20 and the third stage is the the mature one at the age of 20~33.The effect of mixed forests of Pinus massoniana and Mangietigla glaula blune,and Pinus massoniana and Cunninghamia lanceola is better,the average height of the Pinus massoniana reached 3.74 m and 3.73 m,the average of diameter reaches 4.01 cm and 3.89 cm.Compared with pure forest,the height increases 12% and 11.7%,the diameter increases 17.5% and 11.5% respectively.