Variation among desert shrub patches in evapotranspiration

A major concern for revegetated desert ecosystem is accounting for the evapotranspiration dynamics which is influenced by the carrying capacity of the soil moisture content. Most field observations indicate that soil moisture at certain depth varies with the stochastically occurrence of rainfall events, and the evapotranspiration at community level also varies with the total of annual precipitation. Based on a study of the long-term field observation on the revegetated desert ecosystem, we find that the evapotranspiration of the shrub community correlates closely to the availability of soil moisture, and it can be quantified by analytical description of the stationary and transient joint behavior of plant evapotranspiration and soil moisture. The experimental results indicate that the size and diversity of plant species in water-limited ecosystem can be determined by plant evapotranspiration, which is a comprehensive indicator for plant water resource competition. These results suggest that revegetating large sandy areas with desert shrubs could reduce soil water storage by transpiration, which could significantly change groundwater recharge conditions. However, from a viewpoint of desert ecosystem reconstruction, it appears that natural rainfall can sustain desert shrubs which would reduce erosion loss of sand.