杉木林下南方红豆杉初期生长分析

调查研究了福建省大田县杉木林下南方红豆杉的初期生长(树高、地径和冠幅)差异。结果表明:3个指标在不同郁闭度、地类及郁闭度与地类交互作用条件下均存在极显著差异。不同郁闭度的杉木林下树高、地径和冠幅平均值大小次序均为郁闭度0.6郁闭度0.7郁闭度0.5郁闭度0.8,表明适当的光照有利于南方红豆杉树高、地径和冠幅的生长,郁闭度过大或过小均对树木生长不利,以郁闭度0.6-0.7为佳。不同地类的杉木林下树高、地径和冠幅平均值大小次序均为Ⅰ类立地Ⅱ类立地Ⅲ类立地,Ⅰ类、Ⅱ类立地有利于南方红豆杉生长,以Ⅰ类立地为佳。不同郁闭度与地类组合的杉木林下树高、地径和冠幅平均值较大的前3种组合均为郁闭度0.6×Ⅰ类立地、郁闭度0.7×Ⅰ类立地和郁闭度0.6×Ⅱ类立地,表明在考虑郁闭度与地类交互作用的条件下,郁闭度0.6-0.7、Ⅰ类立地最有利于南方红豆杉生长。

Study on initial growth of Taxus wallichiana var.mairei under-forest of Chinese fir

The initial growth indexes,height,ground diameter,and crown width of Taxas wallichiana var.mairei under-forest of Chinese fir were investigated in Datian County,Fujian.There was extremely significant difference among three indexes under different canopy densities,site types,and interaction between them.The order of average growth values of height,ground diameter and crown width of under-forest of Chinese fir under different canopy densities was canopy density 0.6>canopy density 0.7>canopy density 0.5>canopy density 0.8,which proved that proper illumination was favorable for the growth of height,ground diameter and crown width.Too high or low canopy densities were unfavorable for tree growth,and the best was canopy density 0.6 to 0.7.The order of average growth values of the height,ground diameter and crown width of under-forest of Chinese fir in different site types was site type Ⅰ>site type Ⅱ>site type Ⅲ,which proved that site type Ⅰand Ⅱ were favorable for the growth of the under-forest and the site type Ⅰ was the best.The top three average growth values of the height,ground diameter and crown width of under-forest of Chinese fir in different canopy density and site type combinations were canopy density 0.6 plus site type Ⅰ,canopy density 0.7 plus site type Ⅰ,and canopy density 0.6 plus site type Ⅱ,which proved that under the condition of interaction between canopy density and site type,the canopy density 0.6 and 0.7 plus site type Ⅰ was the best for the growth of T.wallichiana var.mairei.