科尔沁沙地植被恢复中差不嘎蒿种群不同龄级个体的点格局分析

差不嘎蒿（Artemisia halodendron）主要分布在呼伦贝尔沙地和科尔沁沙地的流动和半固定沙丘上，是良好的乡土固沙半灌木，也是退化沙地固定和植被恢复过程中的建群种。点格局分析方法是20世纪末发展起来的多尺度空间格局分析方法。通过对差不嘎蒿种群的点格局分析，发现差不嘎蒿幼体的空间格局多为集群分布，在各个尺度上都极为显著，而随着差不嘎蒿龄级的增加，其空间分布也逐渐显现为随机分布。差不嘎蒿相邻龄级的空间关系差异不显著，而间隔龄级间则呈空间负相关。这与其幼体聚集，成体随机分布的空间格局相一致。

Point Pattern Analysis for a Population of Artemisia halodendron in a Kerqin Sandlot

Artemisia halodendron is mainly distributed on shifting or semi-fixed sand dunes in the Hulunbeier and Kerqin Sandlands of Inner Mongolia. It is a semi-shrub and a valuable species for sand fixation. A. halodendron is a constructive species for controlling the shifting sand dunes during vegetation restoration. In this study, we used point pattern analysis, a multivariate spatial-pattern analysis method, to examine the spatial pattern of A. halodendron in relation to ground conditions. Young individuals are generally aggregated at all scales, and older individuals display a tendency for random distribution. Individuals of the neighboring age classes show no apparent spatial association, whereas individuals of disjunct age classes show a negative spatial association. This pattern is consistent with the spatial pattern of clustered distribution of young individuals but random distribution of adults.