Application of Lignin Sand-Fixer to Vegetation Restoration in Desertificated Areas Changes of Plant Species Diversity in the Process of Human-Induced Vegetation Restoration in Sandy Lands of Qinghai-Tibet Plateau POINT PATTERN ANALYSIS OF ARTEMISIA ORDOSICA POPULATION IN THE MU US SANDY LAND Assessment on the changing conditions of ecosystems in key ecological function zones in China. Effects of land use and cover change (LUCC) on ecosystem sand fixing service in Inner Mongolia