DISTRIBUTION CHARACTERISTICS OF ROOT AREA OF SABINA VULGARIS UNDER DIFFERENT HABITATS A Study on Water Storage Capacity and Water Availability in Soil of Different Types of Sites in Jiulongshan, Beijing Grading of Soil Moisture Availability and Its Productivity on Goldspur Apple Orchard in Loess Hilly-Gully Region Heterosis of Root Growth in Maize (Zea mays L.) Seedling under Water Stress Study on soils water storage capacity and availability in secondary vegetation types in Ziwuling forest region Variations in Leaf N, P of Picea crassifolia along the Altitude Gradient in Qilian Mountains