Abstract: In this paper, the influences of different thinning intensity on the growth of Cunninghamia lanceolata plantations were investigated in Taoyuan National Forest Farm, Fujian province. The results indicated that the net growth of plant height, diameter at breast height (DBH) and individual volume was increased by 5.7%~37.1%, 12.5%~112.5% and 15.0%~129.8% respectively in C. lanceolata plantation treated by different thinning intensity of 30%, 45%, 60% compared with the control plantation after thinning of six years. Obviously, the plant height, diameter at breast height, individual volume of the plantation with thinning intensity of 60% were increased most significantly among them. However, with the increase of thinning intensity, the stand total volumes had a little decrease. On the basis of these, some suggestions were put forward to big, medium, small diameter timber of C. lanceolata, including thinning number and time, and the cultivation period.

Key words: Cunninghamia lanceolata, thinning intensity, directed breeding

摘要： 对11年生同一坡面杉木林分设立不间伐（CK）和间伐强度30%、45%、60%四个处理，调查不同间伐强度的林木树高、胸径、材积生长状况。试验表明，间伐6年后实施间伐的林分单株树高、胸径、材积的增长量分别比对照高出5.7%～37.1%、12.5%～112.5%和15.0%～129.8%；其中，间伐强度60%林分树高、胸径的增长最为显著，其次为45%间伐强度。但林分总蓄积量增加最多的是对照小区。间伐强度对培育不同径阶的杉木材有重要影响。

关键词: 杉木, 抚育间伐, 定向培育