Abstract: The study of species composition and diversity of plant communities in reclamation area can provide references in understanding and protecting the biodiversity in reclamation area. In this paper, an investigation was conducted on the herb communities in the reclamation areas with different reclamation history in Dongtan of Chongming Island, aimed to understand the variation characteristics of species composition and diversity of herb communities during the succession. In the investigation area, a total of 49 herb species were recorded, belonging to 20 families and 45 genera, among which, Compositae and Gramineae occupied about 45% of the total. Annual herbs dominated in the herb communities. With the increasing duration of reclamation, the species richness and diversity decreased after an initial increase, with the peak value in the 50 years of reclamation. The Jaccard index and Cody index all decreased after an initial increase with the increasing duration of reclamation, and the communities changed intensely in the 20-40 years of reclamation. Conductivity (salinity) was the main soil factor affecting the species diversity of the communities.

Key words: alpine forest, small mammals, habitat characteristics., vegetation, burrow distribution