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作 者 ：郑丽凤;周新年

期 刊 ：武汉植物学研究 2009年 27卷 5期 页码：515-521

关键词：空间结构；择伐强度；天然针阔混交林；

Keywords:Spatial structure, Selective intensity, Natural mixed stand of conifer and broad-leaved trees,

摘 要 ：利用混交度、大小比数和角尺度3个结构参数,研究4种不同择伐强度(弱度13.0%、中度29.1%、强度45.8%、极强度67.1%)对中亚热带天然针阔混交林林分空间结构的影响。结果表明:弱度择伐后林木的平均混交度最大,中度择伐次之,极强度择伐林木单种聚集的比例最高;不同择伐强度对林木的大小分化程度影响不大,但各主要树种的地位都有一定程度变化;择伐并未改变林木的空间分布格局,各样地林分整体和主要树种均为聚集分布,极强度择伐林木多呈团状分布,而弱度、中度择伐树种大多处于不均匀和随机分布。总的来说,弱度和中度择伐有利于林分空间结构的优化。

Abstract:The spatial structure of mid-subtropical natural mixed stand of conifer and broad-leaved trees under different disturbances were analyzed by using 3 kind of structure parameters,which are mingling intensity,neighborhood comparison and uniform angle index.The experimental stands were harvested by selective cutting of different intensities(low intensity of 13.0% in volume,medium intensity of 29.1%,high intensity of 45.8%,over-high intensity of 67.1%) in November,1996.The un-cutting plots were set as controls.The result showed that the forest mingling intensity is the biggest in low selective cutting plots,that of medium intensity cutting ranks the secondary,while over-high intensity cutting plots exhibited aggregation of single species.Selective cutting intensity exerted little influence on diameter differentiation,but the positions of dominant species changed with different extents.Selective cutting did not change the spatial distribution of species.Aggregation distribution was the spatial pattern of either the forest as a whole or the dominant species,regardless of what selective cutting intensity is.The species was in clumped distribution in over-high selective cutting plots,while in non-uniform and random distribution in low and medium selective cutting.Generally speaking,the low and medium intensity selective cuttings may enhance the stability of forest community spatial structure effectively and its communities spatial structure is superior.

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