Responses of contents of soil nutrient factors and water to stocking rates for yaks in Kobresia parva alpine meadow Ⅰresponses to contents of soil nutrient factors and water to stocking rates in summer pasture Effects of Stipa bungeana on Soil Water Contents and Nutrients of Sloping Lands in Loess Plateau of China Influence of Soil Water Content on Vegetation Characteristics in Desert-Wetland Ecosystem in Xihu of Dunhuang,Gansu