We established 1 hm2 sample plot in Xiaoqinling nature reserve,used two statistical models (the constraint model and the non-constraint model) and analyzed the community phylogenetic structure in this region from three different scales 10,20,25 m.The results show:(1) under the non-constraint model,communities were phylogenetically clustered at all spatial scales;Using the constraint model,communities were phylogenetically clustered in 10 m,20 m scale and overdispersed in 25 m research scale.In contrast,community phylogenetic structures tend to disperse with the scale enlargement.Therefore,phylogenetic density dependence becomes the leading factor of the community compositionin the Xiaoqinling deciduous broad-leaved forest.(2) The study results suggest that the impact of space factors on community phylogenetic structure is much greater than that of the terrain factor.With the increasing of the reseach scale,space factors and terrain factors influence gradually increased.Space factors and terrain factors are closely related to different terrain caused by the space difference.Therefore,The space factors are the direct factors affecting the community phylogenetic structure,and terrain factors are the indirect factors.%为探索研究尺度、零模型与群落谱系结构的关系,在小秦岭自然保护区建立1 hm2样地,运用约束型、非约束型零模型分别从10、20、25 m3个研究尺度上分析群落谱系结构,结果表明:(1)非约束型模型下,谱系结构聚集;约束型模型下,10、20 m尺度上,谱系聚集,25 m尺度上谱系分散.对比发现,随研究尺度增大,谱系聚集程度降低,趋于分散,可能是由于环境异质性对物种分布的影响程度降低,密度制约作用增强所致.(2)空间因子对谱系结构的影响远远大于地形因子,随研究尺度增加,空间因子及地形因子的解释量逐渐增大.地形的不同营造了不同的空间差异,二者密切相关.因此,空间因子是影响谱系结构形成的直接因素,而地形因子是间接因素.
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