土壤有机碳/氮对高山草甸水分入渗的影响

Effects of Soil Organic Carbon/Nitrogen on Water Infiltration of Alpine Meadows

以祁连山北麓自然垂直带（2 500~3 000m）高山草甸为对象,通过野外调查和室内样品分析相结合的方法,研究了不同海拔土壤（0~60cm）有机碳和全氮分布及与土壤水分入渗的关系.结果表明,有机碳氮在不同深度土壤中含量并不相同,在表层含量较高,随着土层的加深其含量逐渐递减,且随海拔的上升,土壤有机碳氮含量呈增加趋势,表现为2 800~2 900m〉2 700~2 800m〉2 600~2 700m〉2 500~2 600m.不同海拔高山草甸土壤水分初渗速率随土壤碳氮含量呈同步正相关关系,入渗速率随时间的增加而呈递减趋势,但在不同海拔条件下土壤水分入渗速率的递减率有所差别.

With alpine meadows on an altitudinal gradient （2 500~3 000 m） of the northern slopes of Qilian Mountains as the test objective, the vertical distribution of organic carbon （SOC） and total nitrogen （TN） in soil （0~60 cm） at various altitudes and the relationship with the soil water infiltration were re searched. The results show that the content of organic carbon and nitrogen in the soil is not evenly distributed （higher in surface soil than at other levels） ,and gradually diminishes as the depth of soil increases. The content of organic carbon and nitrogen increases as altitude rises （from 2 500 m to 3 000 m） ,being largest at the altitudes of 2 900~3 000 m. The initial infiltration rate has the significant positive correlation with SOC and TN,and infiltration rate decreases with time,but the decreasing rate of water infiltration varies atdifferent altitudes.