Abstract: Potaninia mongolica is an important constructive species and ancient endemic species in the Alxa Desert, and it is a national secondary key protected plants in China. Investigating the characteristics of the natural communities of Potaninia mongolia and studying its community classification and the relationship between diversity and environmental factors can provide data support for the conservation and long-term monitoring of this species. In this study, the representative communities of Potaninia mongolia was selected in eastern Alxa, the community characteristics were studied by sample method, and the relationship between community species diversity and environmental factors was discussed by redundancy analysis (RDA). The results showed that: (1) A total of 48 plants species were recorded in the investigated communes, belonging to 38 genera of 14 families, dominated by Gramineae, Chenopodiaceae, Compositae and Leguminosae; The life form was dominated by annual (or biennial) herbaceous species, accounting for 33.33% of the total species, perennial herbs (25.00%), shrubs (20.83%) and half-shrubs (20.83%) had similar proportions, but the shrubs was the dominant synusia of the community; The water ecological type was mainly composed of xerophytes, accounting for 79.17% of the total species, of which strong xerophytes accounted for 35.42%, reflecting the strongly arid climatic characteristics. The floristic geographic element was dominated by Gobi species and Gobi-Mongolia species, accounting for 29.16% and 22.92%, respectively, reflecting the floristic characteristics of desert vegetation. (2)According to the life form and dominance degree, Potaninia mongolica desert in eastern Alxa was divided into three association groups: Potaninia mongolica-herbs desert association group, Potaninia mongolica+shrubs-herbs desert association group, Potaninia mongolica+shrubs desert association group, which were further divided into 13 associations. (3) Results of the RDA analysis showed that temperature and precipitation were the main factors influencing the species diversity of the community.

Key words: eastern Alxa, Potaninia mongolica, community characteristic, species diversity, Redundancy analysis