叶山次生落叶阔叶林主要树种空间结构特征

通过对铜陵叶山林场天然次生落叶阔叶混交林内具有代表性的样地调查,利用角尺度、混交度和大小比数3个林分空间结构参数分析了该次生落叶阔叶林林分空间结构特征。结果表明,该林分乔木层共有19个树种,麻栎是该森林类型的优势树种,主要伴生树种为化香、枫香、檫木等;该森林类型林分平均角尺度、平均混交度和平均大小比数分别为0.556、0.525和0.497;在林木空间格局上,林分整体呈团状分布;从林分种间隔离程度来看,整体处于中度混交状态;在林木大小分化程度上,麻栎、化香、枫香和檫木在生长上整体处于中庸状态,林木空间大小分化不大。该森林类型还处在不稳定阶段,即落叶阔叶向常绿与落叶阔叶林演替过程中。

Spatial structure characteristics of main tree species in secondary deciduous broad-leaved forest in Yeshan

Based on the investigation of typical plots of the natural secondary deciduous broadleaved mixed forest in Yeshan Forest-farm of Tongling city,the spatial structure features of this forest type were analyzed by using three spatial structure parameters(uniform angle,mingling degree and neighborhood comparison index).The results showed that there were 19 tree species in tree layer,of which Quercus acutissima was the dominant species of this forest type,and Platycarya strobilacea,Liquidambar formosana,Sassafras tzumus and so on were main associated tree species;the mean value of uniform angle index,mingling degree and neighborhood com-parison of the stand in forest type were 0.556,0.525 and 0.497,respectively.The pattern of tree spatial distribution of the stand was the cluster.The mingling degree of tree species of the stand was moderate mixed.Quercus acu-tissima,Platycarya strobilacea,Liquidambar formosana and Sassafras tzumus were the mean state in growing in the tree’s size differentiation degree.The tree’s size differentiation of this forest type was small.This forest type is still in the unstable stage,namely the transition stage from the deciduous broadleaved forest to the evergreen and deciduous broadleaved mixed forest.