Characteristics of Species Diversity of Herb Community in the Polder of Returning Farmland to Lake in the Dongting Lake Region: Characteristics of Species Diversity of Herb Community in the Polder of Returning Farmland to Lake in the Dongting Lake Region

In order to understand the species diversity of herb community which small mammals would depend on in the area of "Returning Farmland to Lake" in the Dongting Lake region,field investigation were conducted in 2005 and 2009 in different habitats,including farmland,single restoration polders(SRP),reconverted beach from farmland(RBF) and aboriginal beach.The species abundance,dominant concentration index,Shannon-Weiner diversity index and evenness index by Pielou were compared.Results indicated that herb community in SRP was still similar to the characteristic of species diversity of the normal farmland.However,herb community in RBF changed significantly,where species abundance became less than that in the normal farmland,and at the same time,differed from that in the beach(climax herb community adapted to submergence in summer).The characteristics of herb community in RBF swung among seasons,more like that in original beach in autumn after flooding withdrawal,but more like that in farmland in spring before flooding submergence.Therefore it was concluded that the herb community was being in succession procession from farmland to beach.Comparison of data from 2005 and 2009 showed that the succession of herb community was in the low speed stage.