对北京小西山油松（Pinus tabuliformis Carr.）纯林、栓皮栎（Quercus variabilis Bl.）纯林和油松-栓皮栎混交林天然更新群落的乔木种类进行调查，基于净谱系亲缘关系指数(NRI)和净最近种间亲缘关系指数(NTI)对3种人工林天然更新群落的谱系结构进行分析，并运用方差比率（VR）、χ2检验、Spearman秩相关系数和联结系数对主要树种（重要值大于或等于10%）的种间关联性进行分析。结果表明：油松纯林、栓皮栎纯林和油松-栓皮栎混交林天然更新群落树种分别有9科12属12种（含变种，下同）、12科16属20种和12科13属17种，主要树种分别有7、9和8种。油松纯林天然更新群落的NRI和NTI值在5 m×5 m、5 m×10 m和10 m×10 m取样尺度均为负值；栓皮栎纯林天然更新群落的NRI和NTI值在5 m×5 m、5 m×10 m、10 m×10 m和10 m×20 m取样尺度均为正值；油松-栓皮栎混交林天然更新群落的NRI值在4个取样尺度均为正值，NTI值在5 m×5 m、5 m×10 m和10 m×20 m取样尺度均为负值。油松纯林和油松-栓皮栎混交林天然更新群落主要树种的VR值分别为0.90和0.97，统计量（W）分别为21.52和23.28，说明群落总体为不显著负关联。油松纯林的χ2检验、Spearman秩相关系数和联结系数分析获得的正负关联比分别为1.3、0.8和1.3，而油松-栓皮栎混交林的正负关联比分别为0.8、1.2和0.9。栓皮栎纯林天然更新群落主要树种VR值为0.47，W值为11.28，说明群落总体为显著负关联；χ2检验、Spearman秩相关系数、联结系数分析获得的正负关联比分别为0.6、1.0和0.7。综合分析认为，北京小西山油松纯林和栓皮栎纯林天然更新群落谱系结构分别以发散和聚集为主，而油松-栓皮栎混交林天然更新群落谱系结构为不显著聚集，但在近缘种上主要表现为不显著发散。3种人工林天然更新群落主要树种的总体关联性为负关联，群落稳定性较差。

The arbor species in natural regeneration communities of Pinus tabuliformis Carr. pure forest, Quercus variabilis Bl. pure forest, and P. tabuliformis-Q. variabilis mixed forest in Xiaoxishan Mountain of Beijing were investigated, and the phylogenetic structures of natural regeneration communities in three plantations were analyzed based on net relatedness index (NRI) and nearest taxon index (NTI), meanwhile, the interspecific associations between main tree species (important value greater than or equal to 10%) were analyzed by using variance ratio (VR), χ2 test, Spearman rank correlation coefficients, and association coefficients. The results show that the tree species in natural regeneration community of P. tabuliformis pure forest,  Q. variabilis pure forest , and  P. tabuliformis-Q. variabilis mixed forest are 12 species (including varieties, the same below) in 12 genera of 9 families, 20 species in 16 genera of 12 families, and 17 species in 13 genera of 12 families, respectively, and the main tree species are 7, 9, and 8 species, respectively. The NRI and NTI values of natural regeneration community of P. tabuliformis pure forest are all negative at the sampling scales of 5 m×5 m, 5 m×10 m, and 10 m×10 m; those of natural regeneration community of Q. variabilis pure forest are all positive at sampling scales of 5 m×5 m, 5 m×10 m, 10 m×10 m, and 10 m×20 m; the NRI values of natural regeneration community of P. tabuliformis-Q. variabilis mixed forest are all positive at four sampling scales, while the NTI values are all negative at the sampling scales of 5 m×5 m, 5 m×10 m, and 10 m×20 m. The VR values of main tree species in natural regeneration community of P. tabuliformis pure forest and P. tabuliformis-Q. variabilis mixed forest are 0.91 and 0.97, respectively, the statistics (W) are 21.52 and 23.28, respectively, indicating that the communities  are not significantly negatively associated in general. The positive and negative association ratios of P. tabuliformis pure forest obtained by χ2 test, Spearman rank correlation coefficients, and association coefficients analyses are 1.3, 0.8, and 1.3, respectively， while those of P. tabuliformis-Q. variabilis mixed forest are 0.8, 1.2, and 0.9, respectively. The VR value of main tree species in natural regeneration community of Q. variabilis pure forest is 0.47, the W value is 11.28, indicating that this community is significantly negatively associated in general; the positive and negative association ratios obtained by χ2 test, Spearman rank correlation coefficients, and association coefficients analyses are 0.6, 1.0, and 0.7, respectively. It is suggested that the phylogenetic structures of natural regeneration communities of P. tabuliformis pure forest and Q. variabilis pure forest in Xiaoxishan Mountain of Beijing are mainly divergent and aggregated, respectively, and that of natural regeneration community of P. tabuliformis-Q. variabilis mixed forest is non-significantly aggregated, but it is mainly non-significantly divergent in related species. The overall association between main tree species in natural regeneration communities of three plantations is negative association, and the community stability is relatively poor.