Water content variations and respective ecosystems of sandy land in China

Soil water conservation is essential to the sustainability of sandy farming . In this paper, longterm observation of soil water, dry soil thickness and soil chemical changes are evaluated at eight locations in sandy soil. This paper subdivides the sandy lands and deserts of China into three climate z ones: and (hyperarid and extremely arid), semiarid, and humid (subhumid and subtropical humid), with respect to the bioclimatic zone, aridity, soil wa ter content, and soil chemical characteristics. The water movement conditio ns, and chemical variations in each zone are analyzed. The paper also estim ates the spatial and temporal correlation function of and soil thickness an d soil moisture. Sandy soils organic matter content, CaCO3 content, soluble salts content are investigated. Afforestation and selection of tree specie s in different sandy areas are suggested to regulate sandy land soil moistu re. Sandy land in China can be divided into the four sand stabilization reg ions according to the shifting sand conditions and the techniques advanced: regions I, II, III, and IV. These results have important implications for remote sensing of soil moisture and soil organic carbon, and soil moisture parameterization in climate models.