CHARACTERISTICS OF RIPARIAN PLANT COMMUNITY IN YANGTZE FINLESS PORPOISE EX-SITU RESERVE IN XIJIANG OXBOW, ANQING CITY

The Xijiang Oxbow located in the Anqing section of Yangtze River is the only ex-situ conservation area for the Yangtze finless porpoise (Neophocaena asiaeorientalis). In order to understand the plant community structure in riparian zone of the Xijiang Oxbow and the habitat of the Yangtze finless porpoise in this area, the vegetation in 10 transects of the Xijiang Oxbow was investigated in the summer, 2017. This study identified 166 species of vascular plants with 50 families and 131 genera including 1 family with 1 genus and 1 species of algae, and, 1 family with 1 genus and 2 species of ferns, as well as 163 species of 129 genus belonging to 48 families of seed plants. The main families were the Papilionaceae, Compositae and Gramineae, and the distribution types of families and genera were relatively rich. Besides, plant community structure showed that Shannon-Wiener indexes were between 0.213—0.899 with a mean of 0.629±0.399, and Simpson indexes were between 0.135—0.465 with a mean of 0.315±0.204. The richness of species ranged from 3 to 14 with the same trend as the diversity indexes. The vegetation distribution in riparian zone of the Xijiang Oxbow presents a significant spatial feature. The areas destroyed by human activities on both sides of the river have lower diversity compared to the natural area covered by plant that has higher community diversity and richness. In general, the riparian zone of the Xijiang Oxbow has rich vegetation and high coverage to improve water quality and provide a good spawning and feeding ground for small settled fish, which own great significance to maintain the habitat and breeding for the migratory population of the Yangtze finless porpoise.