Based on the growing-season field measurements of seventeen arbor sites and fifteen shrub sites and combined with the meteorological data

the actual evapotranspiration during the growing season for arbors and shrubs were calculated and compared

and the impacts of precipitation

initial soil water storage and potential evapotranspiration on actual evapotranspiration with different precipitation patterns were analyzed.The results showed that the amount of growing-season actual evapotranspiration for arbors was higher than that for shrubs in both the dry and wet years.The influencing factors of actual evapotranspiration were different with different precipitation patterns. In the wet year

the actual evapotranspiration was mainly influenced by the precipitation

followed by the potential evapotranspiration;while in the dry year

the major fate for that influences the actual evapotranspiration was initial water storage

followed by the precipitation.This study provides a guide for vegetation reconstruction of the Loess Plateau.