不同栽植代数29年实生杉木生长规律的研究

GROWTH PATTERN OF 29 YEAR OLD CHINESE FIR GROWN FROM SEED IN DIFFERENT ROTATIONS

通过对南平溪后２９年实生杉木不同连栽代数生长过程的分析，结果表明：１代和２代杉木在１０年生前树高、胸径和材积的生长量相近，此后，２代的生长迅速下降（早衰），２９年生的平均单株材积比１代的下降４１４６％。３代杉木树高、胸径和材积生长一开始就比２代的差，但未出现大幅度的衰退现象，２９年生的单株材积比２代的下降１７７０％。杉木栽植代数越少，生长高峰出现时间越早，峰值越大，速生期持续时间亦越长。

Through analysis on growth process of 29 year old Chinese fir stand from seed in different rotation of continuous planting in Ancaoxia,Nanping,Fujian,the results showed that,before ten year old,the increment of tree height,D B H and volume for the first and the second rotations were close, after that,the growth of the second rotation declined rapidly,the mean individual volume of 29 year old decreased by 41.46 percent compared with that of first rotation. The growth of tree height, D B H and volume of the third rotation were lesser than those of the second rotation at the beginning, but decline did not occur to a large range at last, the mean individual volume of 29 year old trees reduced by 17.70 percent compared with that of the second rotation. The fewer of the planting, the earlier of the time reaching peak growth,the bigger of the peak value, and the longer of sustainable time over the fast growing period.