长白山次生杨桦林优势更新幼苗空间分布及环境解释

为了解长白山次生杨桦林中优势更新幼苗的空间分布及其与环境因子之间的关系，以5.2 hm²（200 m×260 m）固定样地更新幼苗的全面定位调查和环境因子调查本底数据为基础，对样地内个体数量排序前5的优势更新幼苗进行分析。结果表明：在中小距离尺度上，水曲柳（Fraxinus mandshurica）（0-90 m）、色木槭（Acer mono）（0-60 m）、紫椴（Tilia amurensis）（0-60 m、90-150 m）和假色槭（Acer pseudo-sieboldianums）（0-90 m）更新幼苗的空间分布关系为显著正自相关，呈聚集性分布；群落水平上，环境变量和空间变量对5种优势更新幼苗的空间分布变异解释能力为61%，其中，纯粹空间变量的解释度为56%，而纯粹环境变量的解释度不足1%；种群水平上，环境因子对更新幼苗的空间分布有一定影响，其中，水曲柳幼苗的空间分布与土壤有机质、土壤全钾和土壤水分显著相关，色木槭幼苗的空间分布与土壤有机质和土壤全磷显著相关，紫椴幼苗的空间分布与土壤全磷显著相关，假色槭幼苗的空间分布与土壤水分显著相关；簇毛槭（Acer barbinerve）幼苗的空间分布与环境因子未表现出显著的相关性。长白山次生杨桦林中优势更新幼苗多为聚集性分布，环境因子对其分布有一定影响。

Spatial distribution of dominant regeneration seedlings and environmental interpretations of secondary poplar-birch forest in Changbai Mountains, China

This paper aimed to study the spatial pattern of main tree seedlings and its relationship with environment factors in a secondary poplar-birch forests in Changbai Mountains of northeasten China. All tree seedlings with DBH<1 cm within a 5.2 hm² (200 m×260 m) plot were mapped in 2008. The spatial pattern of 5 tree seedlings was investigated, and the relationship between spatial pattern of tree seedlings and environment factors was analyzed. The results indicated that on small scales, Fraxinus mandshurica (0-90 m), Acer mono (0-60 m), Tilia amurensis (0-60 m,90-150 m), and Acer pseudo-sieboldianum (0-90 m) showed significantly spatial autocorrelation, that is, there was an aggregated pattern. The environmental variables and spatial variables showed strong interpretation on spatial variation of seedlings at the community level, with an explanatory power of 61%. Pure spatial variables exhibited strong interpretation power of 56% while pure environmental variables accounted only about 1%. The spatial pattern of Fraxinus mandshurica was significantly correlated with soil organic matter, soil moisture, and total K. The spatial pattern of Acer mono was significantly affected by soil moisture and total P. The spatial pattern of Tilia amurensis was significantly influenced by total P. The spatial pattern of Acer pseudo-sieboldianum was significantly affected by soil moisture. However, no environmental factor had significant effect on spatial variation of Acer barbinerve. Most of the main tree seedlings showed an aggregation pattern, and environmental factors had a certain influence on their distribution.