辽东山区原始阔叶红松林主要树种空间结构特征

维持森林结构多样性通常被认为是确保森林生态系统稳定性和生物多样性的有效方式.本研究以辽东山区原始阔叶红松林为对象,运用相邻木空间关系构建林分空间结构参数,探究顶极群落内部主要优势乔木的空间结构特征,并以此顶极群落为借鉴,为低质量次生林改造和人工纯林结构优化经营提供参考.结果表明: 辽东山区原始阔叶红松林林分的径级分布呈倒“J”形,林下更新良好,同时保持一定比例的大径木存在;林分平均角尺度为0.507,整体呈随机分布状态,混交度平均值为0.82,混交度强;平均大小比数为0.506,反映出林分整体处于中庸状态.林分中不同优势度在极强混交维度下出现了一定程度的分化,反映出处于中下层绝对劣势的小径级被压木和主林层的绝对优势木在不同垂直空间上的优化分布与利用.林分中各优势树种的分布也随机镶嵌于总体的随机格局之中.

Spatial structure characteristics of the main tree species in a mixed broadleaved Korean pine (Pinus koraiensis)forest in a mountainous area of eastern Liaoning Province,China

Maintaining forest structural diversity is generally considered as an effective way to preserve forest stability and biodiversity. The spatial structure characteristics of the dominant tree species in a climax community were investigated in a primary mixed broadleaved Korean pine (Pinus koraiensis) forest in a mountainous area of eastern Liaoning. Stand spatial structure parameters were determined based on the relationships among neighboring trees. The climax communities were used as a theoretical reference for optimizing the spatial structure of a low-quality secondary forest and monoculture plantation. The diameter distribution of the trees in the pine forest exhibited an inverse J-shape, indicating that understory regeneration was relatively good and with certain proportion of large-diameter trees. The main tree species were randomly distributed across the whole plot (=0.507) and in an intensively mixed state (=0.82). An average DBH comparison of trees in the stand indicated that they were at a intermediate status (=0.506). There was a differentiation among different dominances along the high intensity mixed dimension in the stand, indicating an optimal distribution of understory trees and the rational utilization of resources. Trees in the small diameter category were at a state of complete compression, while canopy trees were at a state of complete dominance in terms of their vertical space. Individuals of each dominant tree species were randomly scattered, with a random pattern of individuals throughout the climax community.