塞罕坝机械林场不同林分类型空间结构的比较

用大小比数、角尺度和混交度3个指标对塞罕坝地区不同林分类型内的样地进行比较。结果表明:在林分分化方面,各林分存在一定程度的竞争,但不影响林木的生长,其中2、3、5和7号样地所在林分的分化趋势较严重,应当考虑进行适当的营林抚育措施;9个样地所在林分的林分平均角尺度均为0.50～0.60,林木分布为聚集分布;混交林分平均混交度均不高,为弱度混交。可见,在资源经营中应根据林分空间结构的分析结果和各林分不同的经营目的,进行适当营林活动。

Comparison of spatial structures among different stand types in Saihanba Mechanized Forest Farm

This study compared the spatial structures among different stand types in Saihanba Mechanized Forest Farm by using three indices, i.e. the neighborhood comparison, uniform angle index and mingling degree. The results show that there exists competition within the stands, which did not affect the growth of trees. In the sample plots, No.2, 3, 5, 7, the differentiation within stands was quite obvious, indicating that we should take some forest management and tending measures. The mean values of uniform angle index in nine sample plots ranged from 0.50 to 0.60, which showed an aggregation distribution pattern. In the mixed forests, the average mingling degree were low, suggesting a less-mixed degree. According to spatial structures and different management purposes of the stands, we can take reasonable measures for forest management.