Response of Salix psammophila seedlings to simulated precipitation change in Ordas plateau STUDIES ON REGULATING FUNCTION OF FOREST HYDROLOGY AND MICROCLIMATE IN ARID AND SEMI-ARID AREA OF WEST CHINA Artificial neural network model of spring wheat growth system in semi-arid areas and yield forecast Effects of plastic film mulch and pre-sowing soil water on growth and yield of spring wheat in semi-arid areas of Loess Plateau