择伐强度对长白山区天然云冷杉针阔混交林空间结构的影响

利用混交度、大小比数、角尺度3个林分空间结构参数,分析研究了不同择伐强度(未择伐、20%、30%、40%)对长白山区天然云冷杉针阔混交林林分空间结构的影响。结果表明:20%择伐强度的样地平均混交度最大,30%择伐次之,40%择伐样地平均混交度最小;不同择伐强度对林木大小分化程度影响不是太大:20%择伐样地林木成均匀分布,未采伐样地和30%采伐样地林木成随机分布,40%择伐样地林木成团状分布。总的来说,20%择伐更有利于云冷杉针阔混交林林分空间结构的优化。

Influence of the Selective Intensity on Spatial Structure of Natural Spruce-fir Mixed Stands of Coniferous and Broad-leaved Trees in Changbai Mountains

Selective cutting operation was adopted with different intensities of cutting(no cutting,20%,30%,and 40%) in natural spruce-fir mixed stand located in Changbai Mountains,China to examine the influence of cutting on spatial structure of the stands.Three structure parameters(mingling,neighborhood comparison,and uniform angle index) were calculated.The results showed that the average mingling intensity of the plots with the cutting intensity of 20% was the biggest,the cutting intensity of 30% ranked the secondary,while the cutting intensity of 40% was the least.Selective cutting intensity exerted little influence on diameter differentiation.The species was in uniform distribution in the plots with cutting intensity of 20%.The species was in random distribution in the plots with cutting intensity of 30% and in no selective cutting plots,while in round state distribution in the plots with cutting intensity of 40%.Generally,the cutting intensity of 20% might enhance the stability of forest community spatial structure effectively and its communities spatial structure was superior.