Distribution patterns of desert plant diversity and relationship to soil properties in the Heihe River Basin, China

The study on the patterns of plant species diversity and the factors influencing these patterns forms the basis of ecology and is fundamental to conservation biology. In this paper, desert plant species diversity and soil properties (nutrient and texture) were investigated along desert region of the Heihe River Basin (HRB) to determine whether soil environmental factors influenced desert plant species diversity. We found a total of 44 shrub and herb species belonging to 40 genera of 17 families. The largest family was the Compositae, accounting for 25.0% of the total. Twenty-four survey plots were clustered into eight plant community types. The Margalef richness (D), Simpson dominance (C), Pielou evenness (J(sw)), and Shannon-wiener (H) index differed significantly among community types. Redundancy analysis (RDA) revealed a relatively strong relationship between the species diversity and soil environmental factors. The first RDA axis accounted for 80.5% and 81.8% of the variation in soil nutrient and texture properties, respectively, but was not statistically significant. RDA suggested that total phosphorus (TP) and medium sand (0.25-0.5 mm) content were the only two statistically significant factors in the study area. Both classification and ordination resulted in a clear demonstration of the spatial variability of community and soil properties. In general, the distribution pattern of desert plant community was mainly related to soil nutrient and texture properties factors, but the relation was not strong. This study provides insights into desert plant diversity and community conservation of Inland HRB in arid desert ecosystems.