不同稳定性群落下飞机草种群格局的分形特征

Changes of the fractal characters of the spatial pattern of Eupatorium odoratum populations in different types of stability habitats

为揭示桂西南喀斯特区域不同群落的稳定性对飞机草种群入侵、定居、生存和发展能力的影响,笔者运用分形理论中的计盒维数和信息维数研究了不同稳定性群落下飞机草种群的格局分形特征。结果表明,不同稳定性群落的飞机草种群格局分形特征不同。稳定性强的群落飞机草分布格局计盒维数和信息维数均较小,种群占据空间的能力较弱;稳定性中等的群落飞机草的格局分形特征存在计盒维数较大和较小2种情况,反映了飞机草在剧烈的种间竞争中所处的地位强弱状况,信息维数较小则说明飞机草种群聚集强度较弱,个体分布均匀;稳定性差的群落飞机草格局计盒维数较大,飞机草种群空间占据能力较强,信息维数存在较大和较小2种情况则隐含飞机草种群聚集强度随着群落的演替发展而变小。

To reveal the effects of different types of stability habitats in karst region of Southwest Guangxi on invasion,settlement,survival and development capacity of Eupatorium odoratum populations,the fractal characters of Eupatorium odoratum population were studied in different types of stability communities by boxing-counting dimension and information dimension.The results showed that,the fractal characters of Eupatorium odoratum population patterns variated with the changes of community stability.Boxing-counting dimension and information dimension were both lower,reflecting low spatial occupation abilities and weak individual spatial distributions of Eupatorium odoratum populations in high stability habitats.Boxing-counting dimension was higher or lower,which reflected the variation status degree of Eupatorium odoratum populations in the fierce competition,and lower information dimension of Eupatorium odoratum populations disclosed weak scale degree of populations pattern intensity and lower evenness of individual distribution in middle type of stability habitats.Boxing-counting dimension was higher,reflecting higher spatial occupation degrees,and information dimension was higher or lower,implying the more development of community succession,the weaker scale degree of pattern intensity of Eupatorium odoratum populations in low type of stability habitats.