中文摘要：

采用空间结构参数（角尺度、混交度、大小比数）一元分布和二元分布探讨小陇山林区百花林场次生松栎混交林群落及其油松、锐齿栎优势种群的结构特征。结果表明：群落和油松、锐齿栎种群中多数林木和各自总体处于随机分布;大小比数频率分布较均匀,整体生长均处于中庸状态;群落中混交良好的林木较多,油松和锐齿栎种群中度混交和强度混交的林木较多,混交度均值（珡M）分别为0.572、0.592,空间隔离程度明显低于群落（0.696）。群落和油松、锐齿栎种群中同一优劣程度或混交等级的林木大多处于随机分布,林分中较为常见的结构单元参照树周围相邻木大多为随机分布的其它树种,同一分布格局或混交等级的林木处于不同优劣程度的林木比例近似相等;但同一优劣程度下,群落中的林木大多混交良好,油松种群中的林木大多处于中度混交,锐齿栎种群中则大多处于强度混交。群落及油松和锐齿栎种群空间结构一元分布、二元分布特征基本一致,说明油松和锐齿栎种群在很大程度上决定了群落的结构特征和发展趋势。

英文摘要：

We used the univariate distribution and bivariate distribution of spatial structure parameters（ uniform angle index,mingling,and dominance） to study the structural characteristics of the secondary pine oak mixed forest community,Pinus tabulaeformis and Quercus aliena var. acuteserrata dominant populations in Baihua Forest Farm at Xiaolongshan. In pine oak mixed forest community,P. tabulaeformis and Q. aliena var. acuteserrata populations,most trees were random distributed,the frequency of different dominance degrees were basically equal,and the overall growth state were medium separately. Most trees were in community mixed well,while trees in two populations were middle mixed and intensive mixed,the mean mingling degree were 0.572,0.592,and significantly lower than the community（ 0.696）. The community and two populations,and most trees with same dominance degree or mingling class were randomly distributed,the most common spatial structure units were the reference tree surrounded by random distributed other tree species,and the same distributed pattern or mingling class trees with different dominance degree had approximately equal frequency. But the same dominant degree of most trees in community mixed was well,while in P. tabulaeformis populations moderately mixed,in Q. aliena var. acuteserrata populations intensity mixed,the univariate distribution and bivariate distribution characteristics of spatial structure in the pine oak mixed forest community,P. tabulaeformis and Q. aliena var. acuteserrata populations were basically the same. Therefore,the dominant populations largely determined the structure characteristics and development trend of the community.