闽楠天然次生林树种间联结性分析

应用方差比率法、2×2列联表的χ2检验以及Spearman秩相关系数对闽楠天然次生林重要值较高的15个主要树种进行联结性分析,同时对目的树种闽楠不同生长期与其他乔木层树种进行关联性分析。结果表明:(1)物种间总体关联性检验表明15个树种总体种间呈不显著正关联,种间联结较为松散,树种的分布有一定的独立性;105个种对的正负关联比为0.91,检验显著率为9.52%。(2)林分中闽楠大树(20 cm≤DBH)、中树(10 cm≤DBH20 cm)、小树(5 cm≤DBH10 cm)与其他乔木层树种所形成的105个种对的正负关联比分别为0.86、0.76和0.69,其检验显著率分别为11.43%、8.57%和5.71%,均表现为大树中树小树,种间联结较为松散,群落处于不稳定发展阶段。

Interspecific association of Phoebe bournei natural secondary forest

We analyzed the associativity of 15 main tree species that have a higher important value in the Phoebe bournei natural secondary forest using the variance ratio (VR) test,x2-test for 2 × 2 contingency table and Spearman's rank correlation coefficient.Meanwhile,we explored the correlation between Phoebe bournei from different growing periods and other tree layer species.The main results were as follows:(1) The overall association showed no significantly positive correlation among the 15 tree species,which meant that most of the species in the community were distributed independently.The ratio of positive to negative association of 105 tree species-pairs was 0.91 with a significant rate of 9.25％.(2) Using diameter at breast height (DBH),Phoehe bournei was divided into three growth periods such as big tree (DBH≥20 cm),middle tree (10 cm ≤ DBH＜20 cm)and small tree (5 cm≤DBH＜ 10 cm).The ratio of positive to negative association between Phoehe bournei in three growth periods and other 105 tree species-pairs was 0.86,0.76 and 0.69,with the significant rate of 11.43％,8.75％ and 5.71％,respectively,indicating that the interspecific association and significant rate of the middle tree was lower than that of the big tree,but higher than the small ones.Based on the above analysis results,it would be concluded that the interspecific association between different species was loose and the forest community was in an unstable developing stage.