祁连山北坡高寒草地狼毒种群格局

Spatial pattern of Stellera chamaejasme population in degraded alpine grassland in northern slope of Qilian Mountains, China

在祁连山北坡高寒退化草地,采用空间序列代替时间序列与点格局相结合的分析方法,研究了小尺度上狼毒种群的组成特征和分布格局。结果表明:伴随狼毒分盖度的增加,狼毒植株数总体上呈现先增大后减小的分布规律;幼株分布格局由随机分布向聚集分布过渡,聚集强度表现出先增强后减弱的规律,成株分布格局基本表现为随机分布;狼毒分盖度较低时,不同大小级狼毒种群在0～100cm尺度上均表现为随机分布,狼毒分盖度较高时,随着种群的发育,分布格局由聚集分布向随机分布过渡。种群的分布格局与种群的扩散阶段存在密切的关系,狼毒种群通过斑块合并、斑块吞并以及竞争作用和协同作用的相互转化实现种群的扩散。

By the methods of point pattern analysis and spatial sequence instead of time series,this paper studied the fine-scale spatial pattern of Stellera chamaejasme population in the degraded alpine grassland in northern slope of Qilian Mountains.With the increasing coverage of S.chamaejasme,its individual number decreased after an initial increase,young plants transited from random distribution to clumped distribution,aggregation intensity weakened after an initial strengthening,and elder plants showed a random distribution.When the coverage was lower,the S.chamaejasme population had a random distribution at 0-100 cm scale;when the coverage was higher,the distribution pattern transited from clumped to random with the development of the population.The spatial pattern had close correlation with the dispersion stage of the population.The dispersion of S.chamaejasme population was realized through the combination and annexation of patches,and the inter-conversion of competition and synergy.