长白落叶松-云杉-冷杉混交林林分空间结构分析

用角尺度、混交度和大小比数3个林分空间结构参数对长白山过伐林区特有的长白落叶松Larix olgensis-云杉Picea jezoensis-冷杉Abies nephrolepis混交林进行了分析,目的是为长白落叶松-云杉-冷杉混交林林分结构的优化调整提供依据。结果表明：该林分的平均角尺度为0.520,林木分布格局为团状分布;林分的平均混交度为0.64,说明它是一个由不同树种组成的呈现中度混交结构状态的较复杂森林群落;从直径大小比数来看,林分中针叶树种具有胸径优势,尤其是云杉的直径优势最突出,红松Pinus koraiensis则分化严重,生长处于劣势。在实际应用中,可以根据林分平均角尺度以及各树种的角尺度、混交度和大小比数,分树种来确定采伐木,逐步使林分结构得到调整,接近最优结构。

Spatial structure of mixed larch-spruce-fir stands

To provide a referencing foundation for structural adjustments in a mixed larch （Larix olgensis ）- spruce （Piceajezoensis）-fir（Abies nephrolepis） stand, found only in the over-logged forest of the Changbai Mountains, three parameters, namely uniform angle index, mingling index, and neighborhood comparison, were used to describe spatial structure. Results indicated that the stand uniform angle index was 0.520; the average stand mingling was 0.64; and for diameter at breast height with the neighborhood comparison, coniferous trees （esp. Piceajezoensis） dominated, with fewer Pinus koraiensis. The neighborhood pattern showed tree distribution was clustered, and the average mingling index indicated the stand was a medium mixed degree. Thus, these three spatial tests could be used to decide the trees and species to cut so as to adjust stands to an optimum structure.