Abstract: Taking the artificial sand-fixing Salix psammophila shrubs with different plant density (0.2, 0.6, and 0.8 plants·m^-2) in Mu Us Sandy Land as test objects, this paper studied the soil moisture dynamics and evapotranspiration during growth season. There existed obvious differences in the soil moisture dynamics and evapotranspiration among the shrubs. The soil moisture content changed in single-hump-shape with the increase of plant density, and in “S” shape during growth season, being closely correlated with precipitation. The evapotranspiration was the highest (114.5 mm) in the shrubs with a density 0.8 plants·m^-2, accounting for 90.8% of the total precipitation during growth season, and the lowest (109.7 mm) in the shrubs with a density 0.6 plants·m^-2. Based on the soil moisture dynamics and water balance characteristics, the appropriate planting density of  S. psammophila shrubs in Mu Us Sandy Land could be 0.6 plants·m^-2.

Key words: Mu Us Sandy Land, Salix psammophila, planting density, water balance