Abstract: In this study, the fixed dunes with vegetation coverage of 10%, 15% and 30% in the Mosuowan region in southern marginal zone of the Gurbantunggut Desert were selected as the typical sample plots to analyze the quadrats, environmental factors and species abundance using the canonical correlation and the means of canonical correlation analysis. Moreover, the relationships among the species diversity and the terrain factors as well as the soil physicochemical factors were analyzed. The results showed that there was a significant correlation between the species and the environmental factors, the first 4 axes could be used to explain 84.4% of total species variation, and soil sand was a sensitive indicator of species distribution. Species were distributed in a large number along the axes. Terrain affected significantly the species of Arnebia decumbens, Amberboa turanica, Echinops gmelinii and Salsola ruthenica; the species that were affected significantly by soil organic matter content, soil moisture content and soil pH value were Schismus arabicus, Ceratocarpus arenarius, Astragalus membranaceus and Erodium oxyrrhynchum. Results of the typical correlation analysis of different indicator groups revealed that the first pair of canonical correlation coefficient between the terrain and the species diversity was 0.54, the first pairs of canonical coefficients of soil physicochemical factors and species diversity were 0.93 and 0.96, the second pairs of canonical coefficients were 0.79 and 0.80, respectively, and there was a significant correlation. Among the topographical factors, the slope index affected mainly the species richness index Simpson; among the soil physicochemical factors, sand and soil organic matter content affected mainly the dominance index Shannon, and soil moisture content and pH value affected mainly the evenness index Pielou. The distribution of species in the study area was jointly affected by both terrain and soil factors.

Key words: soil factor, ephemeral plant, species diversity, canonical correlation analysis, canonical correlation, Mosuowan, Xinjiang