黑河上游高寒退化草地狼毒种群小尺度点格局分析  

Fine-scale spatial patterns of Stellera chamaejasme population in degraded alpine grassland in upper reaches of Heihe,China

作　　者：赵成章[1] 高福元[1] 王小鹏[1] 盛亚萍[1] 石福习[1] 

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070

出　　处：《植物生态学报》2010年第11期1319-1326,共8页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(40971039);国家"十一五"科技支撑计划项目(2007BAD46B07)资助

摘　　要：植被斑块化是自然界的一种普遍现象,斑块的形成和变化对植物种群格局的形成和变化具有重要影响。在黑河上游祁连山北坡高寒退化草地,采用点格局分析方法,研究了小尺度上狼毒(Stellera chamaejasme)种群的种群密度、组成格局以及分布格局。结果表明:随着狼毒种群分盖度的增大,种群密度、领地密度和组成格局呈现规律性的变化,斑块内部狼毒种群的数量出现增减交替变化趋势,组成格局规律明显;狼毒种群的分布格局表现出与尺度关联的变化趋势,在31%–40%分盖度下,狼毒种群在所有尺度上表现为随机分布,在41%–50%、51%–60%、61%–70%、71%–80%分盖度下随着尺度增大,分布格局的基本模式为:随机—聚集—随机或均匀—随机—聚集—随机分布,在聚集状态下,聚集强度不同。以成株为核心的斑块内部种群表现为随机分布或均匀分布,相对于外部表现为聚集分布,随着成株个体数量的逐渐增多,种群竞争关系由种间竞争转化为种内竞争,促进了斑块扩张与合并、斑块增多与吞并,从而实现了种群扩散。Aims The formation and changes of patches has an important effect on population patterns.Our objectives are to determine 1） how patches are formed during the process of Stellera chamaejasme population dispersion,2） what is the effect on pattern during forming and changing of the patch and 3） what roles the formation and changes of the patches play in population dispersion.Methods We studied five 2 m × 2 m plots of different S.chamaejasme cover in the upper reaches of Heihe,China,using the point pattern method to analyze population pattern,size and density.Important findings With increasing cover,the population density and territory density tended to increase,decrease,and then increase and the number of the S.chamaejasme population tended to increase and decrease in turn.In the study area,the pattern under 31%–40% cover at all scales was a random distribution.Under the cover of 41%–50%,51%–60%,61%–70% and 71%–80%,the distribution pattern was random—clumped—random or regular—random—clumped—random and the clumped density was different.It formed patches during the process of S.chamaejasme population dispersion,which was clumped for external and random or regular for internal S.chamaejasme population dispersion through which patches combine and annex.

关 键 词：祁连山北坡 斑块 种群扩散 空间分布格局 狼毒种群 

分 类 号：S812[农业科学—草业科学]