外来杂草北美车前(Plantago virginica)种群分布格局的统计分析

采用连续样方法,分别调查了浙江师大校园内不同定居阶段和生境特点的北美车前(Plantago virginica)种群密度和盖度,以此为基础,计算了北美车前种群分布的偏离系数,并进行了种群的格局规模和格局纹理分析。结果表明:(1)北美车前呈明显的集群分布;(2)多数样点中的北美车前种群存在一个直径在30~50 cm的斑块(包括间隙);(3)随着北美车前种群定居时间延长,种群密度的增加,其斑块数目呈现出少→多→少的变化趋势,这一特点与其种子散布机制有关;(4)种群盖度与偏离系数呈现有统计学意义上的负相关,表明随着定居后时间的延长,外观上北美车前种群的集群分布趋势变弱。

ON INTENSIVE DISTRIBUTIVE PATTERN OF PLANTAGO VIRGINICA POPULTIONS

The coverages and densities of Plantago virginica populations in different inhabiting periods in the campus of Zheijiang Normal University were surveyed by the successive sampling. The deviation coefficients were calculated and the pattern scale and pattern grain were analyzed. The results showed:(1)The populations of Plantago virginica surveyed were obvious clumpy distributed; (2) All the surveyed populations were found with a patch of 30~50 cm in diameter including patch gap;(3)The number of the population patches followed an order as less→more→less, which was related to their seed spread characteristics;(4)negative correlation between the coverages of the populations and their deviation coefficients was found, which showed that the populations of Plantago virginica became less clumping distributed in appearance with the time after their inhabiting.