北京百花山草甸优势种的种间关联性分析

为了探明北京百花山草甸群落的物种组成和种间关系，在对其草甸群落进行样方调查的基础上，利用方差比率法、χ2检验以及种间关联度指数对物种关联性进行了分析.结果表明:北京百花山草甸群落内共有维管束植物92种，隶属于26科66属；以地榆、矮紫苞鸢尾、细叶苔草等28种植物的优势最为明显.该草甸群落内物种整体关联性表现为不显著的负关联；28个优势种组成的378对种对中，有80对存在显著或极显著关联，其中负关联55对，占所有显著或极显著关联对数的68.75%，占所有种对数的14.55%；正关联25对，占所有关联对数的31.25%，占所有种对数的6.61%.表征种间关联程度的Ochiai 指数（OI值）、Dice 指数（DI值）和Jaccard 指数（JI值）具有很高的相似性，其中任何一个指数均能单独表示种间关联程度. 

Inter-specific association of dominant species in Baihua Mountain meadow of Beijing

In order to clarify the species composition and inter-specific association of the meadow community in the Baihua Mountain of Beijing based on the investigation of the meadow, a series of techniques, including the analysis of variance, χ２test, Ochiai’s coefficient(OI),Dice’s coefficient (DI) and Jaccard’s coefficient(JI), were used to analyze the association of the species in the meadow. There were 92 vascular bundle species in the meadow, belonging to 26 families, 66 genera. Of these there were 28 dominant species such as Sanguisorba officinalis, Iris ruthenica var.nana and Carex lanceolata. The overall correlation of all species was negative, but not significant. There were 378 species pairs, which were composed by 28 dominant species and checked by χ2 test. Among these, the inter specific association of 80 species pairs were significant or very significant. Of these, 55 species pairs revealed a significant negative correlation, accounting for 14.55% of all species pairs and 68.75% of the species pairs with a significant correlation. While 25 species pairs showed a significant positive correlation, accounting for 6.61% of all species pairs and 31.25% of the species pairs with a significant correlation. The indices of OI, DI and JI, which are used to show the inter_specific association, all have high similarity, and any of them