Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 ChinaShapotou Desert Research&Experiment Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China;
School of Life Science Lanzhou University Lanzhou Gansu 730000 China;
Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province Institute of Biology Gansu Academy of Sciences Lanzhou Gansu 730000 China;
restoration; shrubs; density; spatial pattern;