Succession characteristics of Zygophllum xanthoxylon communities in the edge regions of Tengger Desert

Based on appearance of Zygophllum xanthoxylon community, crown and numbers of individual plant, the succession processes of Z.xanthoxylon community were classified into three stages, and they were pioneer stage dominated by Oxytropis aciphylla and Z.xanthoxylon stage, canopy closure stage dominated by Z.xanthoxylon+O.aciphylla+Caragana roborovskyi and recession stage dominated by O.aciphylla+C.roborovskyi+Z.xanthoxylon, respectively. A field survey in the edge regions of Tengger Desert was conducted to determine the plant species composition, distribution pattern of population and important value of dominant species of different succession stages in this study. This study showed that 17 plant species were identified in this survey, and they belonged to 14 genera of 7 families. The species richness was not significantly different, and the species diversity firstly increased and then decreased when the Z.xanthoxylon community developed from pioneer stage to recession stage. The ecological dominance was inverse trend with the species diversity. The Z.xanthoxylon population was uniform distribution at pioneer stage, aggregation distribution in canopy closure stage and recession stage. The important value of Z.xanthoxylon was the biggest at canopy closure stage, and the others were the secondary.