浑善达克沙地2种生境下榆树种群空间点格局

The Spatial Point Pattern of Ulmus pumila Population in Two Habitats in the Otindag Sandy Land

以浑善达克沙地固定沙丘与丘间低地2种生境下榆树种群为研究对象,采用点格局分析法对不同生长阶段榆树种群的空间分布格局及其空间关联性进行分析。结果表明:丘间低地种群整体在<10m的小尺度上呈现聚集分布,幼树和中龄树在大尺度上呈随机分布,而成熟树呈现聚集分布;各发育阶段间的空间关联主要表现在小尺度上,随着空间尺度的增加,空间关联性微弱;固定沙丘榆树种群均在小尺度上呈聚集分布,随尺度增大种群呈现随机分布趋势;中龄树和成熟树间在小尺度上呈正关联,各个发育阶段间在大尺度上空间关联性很小。

In this paper Ulmus pumila populations in two habitats of fixed sand dunes and low land between dunes in the Otindag sandy land were targeted and, the spatial distribution patterns and the associations of different developmental stages of the populations by using point pattern analysis. The results showed that the whole population in sandy lands between dunes had a clumped distribution at the scales 10 m. The young trees and middle-aged trees had random spatial distributions at a greater scale,however the mature trees had a clumped distribution. The spatial associations between different developmental stages exhibited at a smaller scale. With increasing scales,the spatial association between different developmental stages turned to be feeble. The whole population on fixed sand dunes had a clumped distribution at a smaller scale. With increasing scales,the population tended to have random spatial distributions. The spatial association of middle-aged trees and mature trees was positively correlated with each other. The spatial associations of different developmental stages were weak.