Relationship Between Soil Properties and Plant Diversity in a Desert Riparian Forest in the Lower Reaches of the Tarim River, Xinjiang, China

Abstract

Based on data from soil characteristics of 217 soil samples collected from 31 soil profiles that were located at eight monitoring sections in the lower reaches of the Tarim River in southern Xinjiang, we analyzed the spatial distribution of soil properties using nonparametric tests and ANOVA. Plant species diversity was analyzed based on vegetation data that were collected over several years. In addition, the study also examined the relationship between plant species diversity and soil parameters by using grey correlation analysis. The results show a significant difference (p < 0.05) in soil organic matter, total N, and total K between the top layer (0–50 cm) and the deep layers (> 50 cm). Along the different monitoring sections, going from the upper to the lower reaches at locations of 150 m away from the right riverbank of the Tarim River, the plant species diversity index (Shannon–Weiner index) has the same trend as total N. Furthermore, plant communities change from compound communities to a single community corresponding to the changes in plant species diversity—namely, from the communities composed of trees (Populus euphratica Oliv.), shrubs (Tamarix spp), and herbs to a pure Tamarix community. Grey correlation analyses indicated that significant relationships exist between plant species diversity, soil organic matter, and total N at the 0–50 cm soil layer.