不同间伐梯度下云南松幼林林分结构及林木生长变化

摘要

Experiments were conducted in 2012 at young growth of Pinus yunnanensis of burned-over area in 2001 in Xishan Forest Farm of Kunming, Yunnan province, with different thinning intensities(10%, 20%and 30%). Investigation in 2014 demonstrated that mean tree height growth increased by 20%at sample plot with 30%thinning and control(no thinning), while 10%at that with 10%and 20%thinning plots. Height growth of dominants had no great difference among different treatments and control, but mean DBH increment had significant difference, 10.96%at control, 41.77 at sample plot with 30%thinning, about 30%at sample plots with 20%and 10%thinning. The experiments indicated that different thinning treatments had no evident effect on tree height growth, but could improve diameter growth.%2012年分别设置10%、20%和30%抚育间伐梯度和对照（不间伐）对昆明西山林场2001年过火地段上自然更新的云南松（Pinus yunnanensis）幼林进行抚育间伐，分析林分结构变化及林木生长情况。2012年和2014年结果表明：样地平均林分密度差异不大，在10500~12500株/hm2，除对照样地出现林分密度增加，这是由于随着林木生长，部分林木进入起测径阶，从而增加了林分密度值。通过采取不同抚育间伐强度措施后，林分平均高变化以对照和30%间伐强度为高，接近20%，而10%和20%两个间伐梯度增长仅略高于10%；林分优势高的变化则在三个梯度及对照之间变化不大，均增加16%以上，最高仅20.00%；而林分平均胸径变化差异较大，对照的仅增长10.96%，而30%的抚育间伐梯度下则增加41.77%，10%和20%两个梯度增加在30%左右；三种抚育强度下直径生长均显著高于对照，但10%和20%两个梯度下差异不显著。因此，抚育间伐管理对于林分高生长影响不大，而对林分直径生长起到较大的提升作用。