Association between vegetation patterns and soil properties in the southeastern Tengger Desert, China

Transitional zones or ecotones between biomes are commonly observable changes in structure and pattern of plant communities. However, there is little understanding of the key soil factors that allow dominant species (woody and herbaceous) from adjacent communities to coexist in transitional zones and how species respond to changes in soil conditions. The objective of this study was to examine the relationship between patterns of shrub and herb species in relation to soils in sandy desert-steppified desert transitional zone. Five transects with a total of 100 quadrats were distributed in different sites to survey vegetation and collect soil samples. The results indicate that fine-textured soil was highly correlated with the percentage of cover and biomass for both shrub and herbaceous species. Shrub cover was positiely correlated with soil moisture at 0.6-1.5 m depth (P<0.01), but was only weakly negatively correlated with bulk density, sand content, pH, and water content in 0-0.6 m of soil layer. Species richness, cover, and biomass for herbaceous species were positively correlated with the percent content of clay, organic matter, and total N. The results of stepwise regression analysis show that soil moisture, texture, and nutrient are highly correlated with the structure and pattern of vegetation.