Abstract: Line transect and plot sampling methods were applied to investigate the beach wetland vegetations in the third core area of Dafeng  Milu National Nature Reserve in  Jiangsu Province, and principal component analysis (PCA), hierarchical cluster analysis, and several diversity indices were adopted to analyze the community characteristics of the vegetations. In 34 sampling plots, a total of 11 species were recorded, belonging to 5 families and 11 genera. The vegetations could be classified into 5 communities, with marked dominant species of herbaceous and few accompanying species. From nearsea to inshore, the distribution of the beach wetland vegetations was Spartina alterniflora co
mmunity→Suaeda glauca community→Zoysia macrostachya community→Phragmites australis community→Imperata cylindrica var. major community. All the communities had low species diversity index, ecological dominance index, and community evenness index, and their species richness had a trend of increasing first, decreasing then, and increasing later. The results of PCA indicated that soil salinity was one of the most important factors affecting the community distribution.

Key words: Upland crop, Rainfall potential use rate, Water supply-demand equilibrium, Water ecological adaptability index (WEAI), Loess hilly zone