皖南山区南方红豆杉种群不同龄级立木的点格局分析

Point pattern analysis of different age-class Taxus chinensis var.mairei individuals in mountainous area of southern Anhui Province

采用点格局分析方法O-ring统计,利用Programita软件对皖南山区霞乡村和仙寓山的南方红豆杉种群不同龄级个体的分布格局及其相互关系进行了分析.结果表明:霞乡村南方红豆杉种群各尺度下均表现为随机分布,而仙寓山南方红豆杉种群在2～25m的空间尺度上呈随机分布,<2m尺度上为集群分布;仙寓山种群Ⅰ龄级在<5m尺度上呈集群分布,而高龄级个体在较多尺度上有偏离随机分布的倾向.随着龄级差距的加大,南方红豆杉幼龄个体与其他个体的空间负关联逐渐显现,而相邻龄级在空间分布上相互独立,关联性很小.南方红豆杉种群的这种空间关系有利于其对资源环境的有效利用,随着个体的生长,南方红豆杉种群的空间分布有一个从聚集到随机的过渡.

By using O-ring statistics in point pattern analysis and Programita software,this paper studied the spatial distribution patterns and associations of different age-class individuals of Taxus chinensis var.mairei populations at Xianyu and Xiaxiang in the mountainous area of southern Anhui Province.The Xianyu population had a random spatial distribution at the scales from 2 m to 25 m but a clumped distribution at the scales 〈2 m,while the Xiaxiang population distributed randomly at all the scales.As for Xianyu population,its individuals of age-class I had a clumped distribution at the scales 〈5 m,while the individuals of elder age-classes tended to be non-randomly distributed at more scales than 〈5 m,which might be related to the features of population regeneration.With increasingly enlarged age-class differences,the spatial association between younger and elder age-classes individuals turned to be negative,but less spatial association was observed between adjacent age-classes individuals.Such a spatial relationship between different age-classes individuals of T.chinensis was beneficial to the effective use of resources.With the growth of the individuals,T.chinensis population had a transition from clumped to random distribution.