山东百部种群的空间分布格局

采用扩散系数的t检验、Poisson分布的x^2拟合检验及Morisita指数的F检验研究了山东百部（Stemona shandongensis）种群的空间分布类型；用负二项参数（K）、Cassie指标（1／K）、Green指数（GI）和Lloyd的平均拥挤度（m^＊）与聚块性指标（PAI）研究其聚集强度。同时利用上述指数研究了取样面积、苗龄对山东百部种群分布格局和聚集强度的影响，分析了分布格局形成的原因。结果表明，总体上山东百部种群的分布格局类型为集群分布，种群聚集尺度多为8m^2；当年生植株种群聚集强度高于多年生种群；整个种群分布格局的演化趋向于高聚集强度的集群分布。

A Study on the Spatial Distribution Pattern of Stemona shandongensis Populations

Four natural populations of Stemona shandongensis were analyzed by t test of dispersion coefficient,F test of Morisita 's index and χ~2 test of Poisson distribution.Their aggregated intensities were measured by using the following indices:Negative binomial parameter (K),Cassie index (1/K),Green index (GI),Lloyd 's index (m~*) and Patchness index (PAI).The influences of block size and seedling age on the distribution pattern and assemble intensity were revealed using those indexes.The causes of forming the distribution patterns were analyzed.The result indicated that the distribution patterns of S.shandongensis populations were clumped.The pattern scale is about eight square meters.The assemble intensities of 1-year-old plant populations were higher than those of perennial plant populations.The evolutionary of S.shandongensis populations are becoming higher in assemble intensity.