利用Moran’sI指数和双相关函数g(r)分析7个主要树种的空间分布格局,检验了环境因子与树种空间分布之间的关系。结果表明:色木槭幼树和小树不具有空间自相关结构,其他树种或生长阶段均呈显著正空间自相关。同一树种的不同生长阶段(幼树、小树、大树)具有不同的空间分布特征;7个树种在绝大多数空间距离上呈随机分布,少数空间距离上呈聚集分布,并且这种聚集性主要表现在较小的空间尺度上。环境变量对紫椴的空间分布具有较强的解释能力,对紫椴幼树、小树及大树空间变异的解释能力分别为23.6%、19.7%和27.5%。环境因子分别解释了蒙古栎幼树2.4%和小树27.1%的空间变异,香杨小树6.8%的空间变异,对蒙古栎和香杨大树空间分布的解释能力较低。环境因子对臭松、红松、色木槭及白桦的空间分布无显著影响。树木种群的空间自相关性是7个优势树种形成特定空间格局的主要原因。
Moran' s I index and mark correlation function g (r) were used to study the spatial distribution pattern of seven main tree species in conifer and broadleaved mixed forests in Changbai Mountains of northeastern China, and to test the correlations between environmental factors and species abundance patterns. The results showed that, saplings and small trees of Acer mono didn't have significant spatial correlation, whereas other tree species or life stages showed significant positive spatial correlation. Different growth stages (saplings, young and mature trees) of specific tree species appeared different spatial structures; all seven tree species showed randomness at the majority of the studied spatial distances, and aggregation only at a few spatial distances. In addition, the aggregation distribution mainly appeared at small spatial scales. Environment variables exhibited strong interpretation power for spatial distribution of Tilia amurensis : 23.6 %, 19.7 % and 27.5 % for saplings, young and mature trees, respectively. However, environment factors only explained spatial variations of 2.4% and 27.1% for saplings and young trees of Quereus mongolica respectively, and 6.8% for young trees of Populus koreana. Environmental factors had no explanation power for mature trees of Q. mongolica and P. koreana. These environmental factors didn't exhibit significant impact on spatial distribution of Abies nephrolepis, Pinus koraiensis, Acer mono and Betula platyphylla. It is concluded that spatial correlations of tree populations generate specific spatial patterns in the seven studied tree species in the Changbai Mountains of northeastern China.