天然林不同强度择伐后林分空间结构变化动态

基于长期跟踪复测数据,利用混交度、大小比数和角尺度3个结构参数,研究了4种不同强度择伐(弱度13.O％、中度29.1％、强度45.8％、极强度67.1％)后天然林林分空间结构的变化动态.结果表明:弱度和中度择伐后林分平均混交度和大小比数呈增长趋势,强度和极强度择伐则呈下降趋势；择伐并未改变林木的空间分布格局,各样地林分均为聚集分布,中度择伐处于随机分布状态的林木数大幅增加.总的来说,弱度和中度择伐后林分空间结构正趋向优化.

Tracking Analysis of Forest Spatial Structure Change after Different Selective Cutting Intensities in a Natural Forest

Based on long-term tracking retest data and three structure parameters（mingling intensity,neighborhood comparison and uniform angle index）,we investigated the effects of four different selective cutting intensities（low intensity of 13.0% in volume,medium intensity of 29.1%,high intensity of 45.8%,and over-high intensity of 67.1%） on forest spatial structure change in a natural forest.After low and medium selective cutting forest,plot average mingling and neighborhood comparison increased while high and over-high selective cutting decreased.Selective cutting did not change the forest spatial distribution pattern.However,the variety of forest plot showed aggregated distribution,and medium selective cutting in random distribution state forest number increased considerably.After low and medium selective cutting,forest spatial structure was optimized in general.