Abstract: We examined the community types and distribution of herbaceous flower species along the riparian zone of the Nanjing Outer Qinhuai River, and explored the main driving environmental factors, aiming to provide scientific basis for improving ecological restoration and constructing river ecological corridor of the Qinhuai River. Based on the survey data, cluster analysis was performed by the unweighted pair-group method with arithmetic means (UPGMA). The plant diversity of different community types was quantified by α diversity indices. The distribution of sampling sites was explored by the DCA, while species and sampling sites were ordinated by the CCA. The results showed that: (1) four different communities of herbaceous flower were identified in riparian zone of the Outer Qinhuai River according to the UPGMA, which was consistent with the results of DCA ordination. (2) Among the four communities, species richness index, Simpson index, Shannon index, Pielou evenness index of the communities Ⅳ, Ⅲ and Ⅱ were higher than those of the community Ⅰ. (3) The first ordination axis showed the strongest correlation with litter thickness, while the second ordination axis was significantly correlated with slope. (4) Distributions of herbaceous flowers and communities in the Outer Qinhuai River were affected by environmental factors.

Key words: Outer Qinhuai River, herbaceous flower, canonical correspondence analysis, species diversity.