Soil moisture enrichment under the desert shrub in the Gurbantungut desert northwest China

摘要

The soil water which is transformed from precipitation is the most important water resource to maintain the growth of vegetation in desert ecosystem. Based on field experiments and observational data, the spatial and temporal distribution pattern andvariability of the soil moisture in the root area of desert shrub in the Gurbantunggut Desert are analyzed. The main results are: (1) The 'soil wet island' with higher soil moisture content exists in the root area of desert shrub. The soil moisture enrichment in the dry summer is stronger than wet spring. (2) The soil moisture spatial and temporal variability is strongest in 80-180cm soil layer in the dry July. This layer is also the main root distribution layer of the desert shrub. (3) March and Aprilafter the snowmelt is the richest period of the soil water in whole year. This period is also the ephemeral plants season. It is considered that the desert shrub stem flow and high infiltration capacity in the root area are the main reason for the soil moisture enrichment in the desert shrub root area.