Abstract: We analyzed the relationships between benthic macroinvertebrate communities and vegetation factors in the salt marsh of Hengsha Dongtan in the Yangtze Estuary. The benthic macroinvertebrate communities were classified into different functional groups according to their feeding habits, feeding form, and life style. The characteristics of benthic macroinvertebrate functional groups and their relationships with the vegetation factors were analyzed. Gastropoda and Malacostraca were the dominant groups. The dominant species were Assiminea sp., A. violacea, A. latericea, Chiromantes dehaani, and Ilyoplax deschampsi. The abundance and biomass of the different functional groups  varied across sites. Among the feeding habit functional groups, omnivores had the greatest number of species, accounting for 50.00% of the total. Herbivores in more than 55.55% (5/9) sites had the highest relative importance index. Among the feeding form functional groups, shredders had the greatest number of species, accounting for 33.33% of the total. Scrapers in more than 44% (4/9) sites had the highest relative importance index. Among the life style functional groups, the number of species of semi-infauna was the largest, accounting for 50.00% of the total. Epifauna in more than 66% (6/9) sites had the highest relative importance index. Different vegetation factors were associated with different functional groups. The abundance and biomass of the feeding habit functional groups were significantly correlated with one or several factors in the combination of rhizome biomass, shoot density, and shoot height of plants (P<0.05). The abundance and biomass of the feeding form functional groups were significantly correlated with shoot height of vegetation (P<0.05). There were significant correlations between the biomass of life style functional group and the combinations of shoot density and height (P<0.05). In the future studies of benthic macroinvertebrate communities, it is necessary to choose the proper functional group classifications according to the research objectives.

Key words: Hengsha Dongtan, benthic macroinvertebrate, functional group, vegetation factor