罕山国家级自然保护区大样地优势树种点格局分析

以罕山国家级自然保护区内森林动态监测大样地为研究对象,采用数量生态学的点格局分析法(Ripley’s K函数),对其优势种的组成及结构、空间分布格局进行分析。结果显示:样地内重要值排在前4位的乔木树种是黑桦(Betula dahurica)、山杨(Populus davidiana)、白桦(Betula platyphylla)和山荆子(Malus baccata),其相对多度之和为98.1%,相对显著度之和为99.68%,是构成样地内植物群落的骨架型乔木植物。样地内林木总径级结构呈近似的指数分布,幼龄期的个体数量最多,植物群落更新良好,属于增长型群落。白桦、黑桦和山杨在不同尺度下的空间分布格局基本都呈集群分布的形式,随尺度的增大,其聚集强度表现为先增大后减小的趋势。山荆子种群的空间分布格局随尺度增大呈现出聚集分布向随机分布转变的趋势。

Point Patterns of Dominant Tree Species in Forest Dynamics Plot of Hanshan National Nature Reserve

Taking the large sample plot in the Hanshan National Nature Reserve as the research object,adopting the quantitative ecology point pattern analysis(Ripley's K function),the composition,structure,spatial distribution pattern of its dominant species were studied.Result of the study is as follows:The arbor species ranked in the top four in importance values in plots are Betula dahurica,Populus davidiana,Betula platyphylla,and Malus baccata.The sum of relative abundance is 98.1%and the sum of relative salience is 99.68%.The skeleton tree plant of the plant community in the field.The structure of the total diameter of the trees in the sample plots showed an approximate exponential distribution.The numbers of individuals in the young age are the largest.The plant community is well renewed and belongs to the growth community.The spatial distribution pattern of Betula platyphylla,Betula dahurica&Populus davidiana at different scales is basically in the form of cluster distribution.With the increase of scale,the aggregation intensity of Betula platyphylla,Betula dahurica&Populus davidiana first increases and then decreases.The spatial distribution pattern of Malus baccata population shows a tendency of aggregating distribution to random distribution as scale increases.