翅果油树群落主要物种空间分布格局及其关联性

以山西省翅果油树自然保护区翅果油树(Elaeagnus mollis)种群为研究对象,采用点格局分析中的O-ring统计方法,利用Programita软件对翅果油树群落中主要物种翅果油树、荆条(Vitex negundo var.heterophylla)和黄刺玫(Rosa xanthina)种群的分布格局及其相互关系进行了分析。结果表明:(1)各种群在相对小的尺度上聚集分布特征明显,随尺度增加各种群主要表现出随机分布特征;(2)各树种间的空间关联性主要表现在小尺度范围,随尺度加大空间关联性逐渐不明显;(3)翅果油树种群径级I、II和III在较小尺度时存在明显的聚集分布,径级IV、V和VI在所有尺度上均呈现随机分布;(4)翅果油树种群径级I和II与径级IV、V和VI存在正关联,同时径级I与VI,径级II与V在一定尺度上表现出空间负关联,相邻径级在空间分布上相关性不显著。

Spatial Distribution Patterns and Association of Major Species in Elaeagnus mollis Communities

Elaeagnus mollis was used as the object of study in the nature sanctuary of Yicheng County, Shanxi province, using O-ring statistics in point pattern analysis and Programita software. We studied the spatial distribution patterns and associations of E. mollis, Vitex negundo var. heterophylla and Rosa xanthina, the major species in E. mollis communities. Three populations showed significantly aggregated distributions at relatively smaller scales and random distributions at larger scales, and the degree of aggregation decreased with increasing spatial scales. Spatial associations among tree species were mainly found at smaller scales and gradually disappeared with increasing scales. E. mollis population size class I, II and III exist in significantly aggregated distribution at smaller scales; size class IV, V and VI in all scales showed random distributions. We found a positive correlation between E. mollis size class I, II and IV, and V and VI, whereas size class I and VI, and II and V exhibited a negative association at a given scale; adjacent size class presenting basic spatial associations was not significant.