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 χ² 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.