中文摘要：

【目的】分析秦岭林区华山松天然次生林群落乔木层、灌木层、草本层各优势种群的种间关联性,揭示群落发育过程中不同种群之间相互作用的内在关联,以期阐明群落发展与演替和种对间关联性内在规律,为秦岭林区华山松群落可持续经营管理提供理论依据。【方法】选取秦岭山地火地塘林区典型华山松天然次生林群落,基于2×2列联表,采用方差比率法测定乔木层、灌木层和草本层各优势种群间的总体关联性;利用χ2检验和Jaccard指数表征乔木层15个优势种群、灌木层19个优势种群、草本层15个优势种群间的种对关联程度及显著性。【结果】华山松天然次生林群落乔木层、灌木层和草本层优势种群间的总体关联性分别表现为不显著正关联、不显著负关联和显著正关联;χ2检验结果显示该群落乔木层、灌木层和草本层均以正关联种对数占绝对优势,分别达81.9%,77.2%和85.7%,负关联种对数次之,分别为15.2%,13.5%和4.8%,无关联种对数较少,极显著和显著正关联种对数分别为11,2和5对,极显著和显著负关联种对数分别为13,2和1对;Jaccard指数结果与χ2检验结果高度一致,该群落3个层次Jaccard指数较高的种对基本都表现为极显著和显著正相关;青榨槭和千金榆、青榨槭和刺叶栎、刺叶栎和少脉椴、山蚂蝗和刚毛忍冬、野草莓和牛尾蒿种对JI值〉0.6,二者之间存在一定的依赖关系,其余种对JI值较小。【结论】秦岭山地华山松天然次生林群落乔木层、灌木层、草本层各优势种对间种间关联明显,该群落总体结构为针阔混交林,物种之间存在一定的独立性,趋于形成一个整体较为稳定的群落。乔木层优势种群种间联结较松散,具有一定的独立性,但独立程度较低,基本趋于稳定,灌木层优势种群则处于动态演替的不稳定阶段,草本层优势种群结构较为稳定。综上所述,种间联结性分析可

英文摘要：

【Objective】The study of interspecific associations of dominant plant populations respectively in the layers of tree,shrub and herb in communities of secondary natural forest of Pinus armandii in Qinling Mountains is to reveal the inherent links of interactions among different populations during the process of community development,to clarify the natural rules of community development in relation to the succession and interspecific association,and to provide the theoretical basis for sustainable management of forest communities of P. armandii in Qinling Mountains.【Method】Typical communities of secondary natural forest of P. armandii in Huoditang Forest Farm in Qinling Mountains were selected for the studies. 2 × 2 contingency tables of species presence / absence data were used as the basis for the analyses of overall interspecific associations among dominant plant populations in different layers of tree,shrub and herb using the variance ratio method. χ2test and Jaccard index were used to characterize interspecific associations of 15 tree species,19 shrub species and 15 herb species. 【Result 】In the community of secondary natural forest of P. armandii, the overall interspecific associations among dominant plant populations respectively in tree,shrub and herb layers displayed non-significant positive,non-significant negative and significant positive correlations. The χ2test showed positive correlations of majority of species-pairs in all layers of tree,shrub and herb,accounting for 81. 9%,77. 2%,and 81. 9%,respectively; followed by negative correlations of species-pairs accounting for 15. 2%,13. 5%,and 1. 8% respectively.Only few species-pairs displayed no correlations. The numbers of species-pairs with extremely significant or significant positive correlations in the 3 different layers were 11,2,and 5,respectively,while those of extremely significant or significant negative correlation were 13,2,and 1 respectively. The JI values were highly consistent with the results of χ2test,indicating that the s