Relationship of spatial heterogeneity for vegetation and aeolian sand soil properties on longitudinal dunes in Gurbantunggut Desert, China

On longitudinal dunes in the southern Gurbantunggut Desert, the vegetation was investigated, and the texture, water content, organic matter, total nitrogen, salt content and pH of aeolian sand soil were measured. By means of geostatistical methods, the spatial heterogeneity for vegetation and aeolian sand soil properties was analyzed. The vegetation pattern and aeolian sand soil properties were moderately to strongly spatially heterogeneous as a whole, with a spatially dependent range of 8.8-74.8 m. Because both of them had a nest structure of grading system, their spatial heterogeneity needed to be described by the fractal dimensions at different sampling scales. The autocorrelated spatial range A (0) and fractal dimensions of the cover of vegetation and the diversity of herberious synusium were similar to these of soil water contents (SM). The coarse grain size (phi 1) and sorting (sigma) of soil, the diversity of herbaceous synusium and the cover of vegetation had a closer dependent range A(0), being 37.8-57.8 m. The trends of spatial variation for organic matter and total nitrogen contents were very similar to that of vegetation cover. The spatial heterogeneities of soil pH and salt content were mainly restricted by terrain and basically not related to vegetation.