托木尔峰国家级自然保护区台兰河上游不同海拔草地土壤持水能力研究

Research on Water Holding Capacity of Grassland Soil at Different Altitudes in the Tuomuer National Nature Reserve

为探究托木尔峰国家级自然保护区不同海拔草地土壤水源涵养能力的空间变化,本研究通过野外调查、土样采集及室内分析,对托木尔峰自然保护区台兰河上游河谷不同海拔草地表层土壤持水能力进行研究。结果表明:研究区草地土壤物理性质随海拔高度的增加表现有所不同,其中平均土壤含水量、非毛管孔隙度、毛管孔隙度和总孔隙度均与海拔表现出显著的正相关关系,随海拔高度的上升均呈现出不断增加的趋势;土壤容重则与海拔存在着极显著的指数负相关关系(R2=0.881 7),即随着海拔高度的增加,土壤容重呈减小趋势。研究区不同海拔草地土壤的水源涵养能力不同,其中最大持水量、非毛管蓄水量和毛管持水量的大小顺序均为山地栗钙土>山地棕钙土>山地棕漠土,即随海拔高度的增加而增大;土壤涵蓄降水量与有效涵蓄量的大小顺序均为山地棕漠土>山地棕钙土>山地栗钙土,随海拔高度的增加而呈下降趋势。海拔高度与放牧及人为活动的干扰强度是导致研究区草地土壤水源涵养功能差异显著的重要因子。

The spatial variation of soil water conservation capacity of grasslands at different altitude in Tuomuer National Nature Reserve was studied based on field investigation,soil sample collection and experimental analysis.The soil water holding capacity of grassland soil at different altitudes in Tailan River valley of Tuomuer National Nature Reserve was analyzed. The results showed that： The physical properties of grassland soil were different with the increase of altitude,and the average soil moisture content,non capillary porosity,capillary porosity and total porosity showed significant positive correlation with the elevation and it showed a constantly increasing trend with the increase of altitude; The soil bulk density showed a significant negative index correlation（R2= 0. 881 7） with the elevation,and it decreased with the increase of altitude. The water holding capacity of the soil was different at different altitudes in the study area. The order of maximum water holding capacity,non capillary water storage capacity and capillary water holding capacity was ranked as： Chestnut soil Mountain brown soil Brown desert soil.They increased with the increase of altitude; The order of soil conservation precipitation and effective conservation quantity was ranked as： Brown desert soil Mountain brown soil Chestnut soil. The altitude and the intensity of grazing and human activities were the important factors that caused the difference of soil water conservation function.