摘要
狼毒为瑞香科根颈型多年生有毒植物。依据株丛枝条数量多少将狼毒株丛划分为 3个级别即Ⅰ级株丛、Ⅱ级株丛和Ⅲ级株丛。采用邻接格子样方法取样 ,运用扩散系数作为聚集强度的测度指标 ,并进行泊阿松分布和负二项分布的Χ2 拟合检验 ;运用Greig Smith的成对样方方差法绘制格局分析图 ,研究了糙隐子草草原 3个放牧演替阶段的狼毒种群的分布格局类型、规模。结果表明 :在重牧、过牧、极牧阶段狼毒种群Ⅰ级株丛均为聚集分布 ,Ⅱ级、Ⅲ级株丛均为随机分布 ;重牧、过牧阶段狼毒种群总体呈聚集分布 ,而在极牧阶段则为随机分布。放牧扰动对狼毒种群的分布格局类型。
Three grades were divided by shoot number of poisonous Stellera chamaejasme cluster, i.g.: cluster grade I, II and III. Sampling was conducted with the method of contiguous grid quadrate, Dispersion Index (v/m ratio) was taken as the index of aggregation intensity, and the simulation tests for Poisson and Negative binomial distribution were performed. Based on pattern analysis diagrams drawn with Greig Smith's PQV, the types and scares of distribution pattern of S. chamaejasme population for three grazing successional stages on Cleistogenes caespitosa grassland were studied. The results showed that at heavy grazing, over grazing and extreme grazing stages, the cluster grade I of S. chamaejasme population turned out to be aggregated, while cluster grade II and III exclusive random, the overall S. chamaejasme population (cluster size neglected) were found to be aggregated at heavy and over grazing stages, while random at extreme grazing stage. In conclusion, grazing disturbance affected distribution pattern types and scares of S. chamaejasme population in different degrees.
出处
《草业科学》
CAS
CSCD
2002年第1期16-19,共4页
Pratacultural Science
基金
国家自然科学基金项目 (39970 537)资助
关键词
狼毒种群
分布格局
有毒植物
放牧演替
草地
植物种群
Stellera chamaejasme population
distribution pattern
poisonous plant
grazing succession
