DYNAMICS OF SPECIES DIVERSITY OF COMMUNITIES IN RESTORATION PROCESSES IN HORQIN SANDY LAND
科尔沁沙地植被恢复系列上群落演替与物种多样性的恢复动态

In this paper species composition and species diversity of communities with different succession times were studied in restoration processes. Our results showed that species richness is 7, 11, 17, 14, 28 and 30 in the communities, of which the succession time is 1, 3, 5, 12, 20 and 30 years, while the species diversity index is 1.458 8, 2.610 0, 3.108 4, 1.696 8, 3.738 6 and 3.639 6 respectively. For life form composition of all communities along the restoration succession series, annual herbaceous plants are dominant, but species number of perennials increases and the dominance of one species is more than that of annuals as succession proceeds. Species number of Chenopodiaceae is stable and their dominance in the community is high, especially in early successional stages. Species number of Gramineae increases continuously along the succession gradient and their importance in community also increases. Ecological dominance declines gradually, while community evenness increases progressively along with succession. In a relatively short time of 30 years the environment of sandy land shifted successfully from mobile sandy land to fixed sandy land, and species composition and community structure improved greatly. This research provided test and sample for the possibility of vegetation restoration under natural condition, as well as a practical pathway for the protection of biodiversity. The most important thing is to stop irrational use of land so that the natural ecological processes of vegetation recovery such as dispersal, inhabitation and propagation can be accomplished continually under stable environments.