Spatial Pattern and Association among Sub-Layers of Typical Mid-Subtropical Natural Broad-Leaved Forest Community

[Objective] The objective of this study was to determine the construction mechanism of typical midsubtropical natural broad-leaved forest community by studying spatial pattern and association based on natural stratification of arbor-layer.[Method] Five plots in size of 50 m × 50 m set up at a location where the forest is nearly old-growth forest community in Wanmulin Nature Reserve in Fujian Province were investigated.The arbor layers of the plots were divided into sub-layers using the maximum light receiving plane(MLRP) method.The spatial pattern of each sub-layer and association of paired sub-layers therefore could be tested based on the spatial point pattern analysis.[Result] The arbor layer of each plot could be divided into light receiving layer(sub-layer Ⅰ) and none-light receiving layer(sub-layerⅡ).Arbor trees in each sub-layer of each plot are mainly in random pattern in the small spatial scale of 0-25 m.Only at a few scales trees of sub-layers deviated from the null model of complete spatial random,a