EFFECTS OF BIOLOGICAL CRUSTS ON THE GERMINATION OF FIVE DESERT VASCULAR PLANTS WITH DIFFERENT SEED MORPHOLOGIES Relationships between plant community characteristics and environmental factors in the typical profiles from Dzungaria Basin Response of the herbaceous layer to snow variability at the south margin of the Gurbantonggut Desert of China Composition and Ecological Distribution of the Algae Living in the Gurbantonggut Desert of Xinjiang