**4. Conclusion**

Soil water recharged by rainwater is the main water source for dominant species on Ordos Plateau. Six woody species have resource-dependent water use strategy, which is an adaptive advantage to the semi-arid climate. On loess slope of eastern Ordos Plateau, *H. rhmnoides, P. tabuliformis* and *A. sibirica* selected different water source based on their availability in the growing season, including shallow soil water, deep soil water and rainwater. In Sandy Land of southern Ordos Plateau, *S. vulgaris*, *A. ordosica*, *S. psammophila* and the company semi-shrub *H. fruticosum* var. laeve used different depths of soil water based on their availability in the growing season. However, there were water competition between the company semi-shrub and two dominant shrubs. Therefore, it was suggested to avoid vegetation degradation resulted from excessive water competition by appropriate distribution and afforestation density in semi-arid region.
