西南岩溶坡地土壤流失的养分含量响应特征研究

Study on the Response of Soil Nutrient Content to Soil Loss in Karst Sloping Land of Southwest China

[目的]研究西南岩溶坡地土壤养分含量对土壤流失的响应特征。[方法]以重庆南川岩溶坡地为例,分析不同位置土壤剖面的基本理化性质以及Mg、Cu、Zn、Mg、Mo、Mn等6种营养元素的迁移特征。[结果]退耕还林坡地中,土壤基本养分与6种营养元素含量从坡顶到坡底都存在不同程度的减少,但在坡体底部又不存在明显的堆积;Mg、Cu、Zn、Mg、Mo、Mn 6种营养元素含量在整个坡体中存在明显的拐点,主要集中在15～25 m,表明岩溶坡地从坡体15 m处开始,土壤流失存在明显的地表流失和地下漏失。[结论]该研究为岩溶山区生态系统的恢复提供了理论依据。

[Objective] The study aimed to analyze the response of soil nutrient content to soil loss in karst sloping land of Southwest China.[Method] Choosing a karst sloping land in Nanchuan,Chongqing city as a sampling area,we analyzed the basic physical and chemical properties of soils at different sampling points,as well as the movement of Mg,Cu,Zn,Mg,Mo and Mn in the soils.[Result] In the sloping land,there was a varying decrease in the content of all soil nutrients from the top to the bottom,but there was no obvious deposit at the bottom.In addition,Mg,Cu,Zn,Mg,Mo and Mn content had clear inflections in the sloping land,and these inflections mainly appeared at 15-25 m.It proved that both surface soil erosion and underground soil leaching occurred at the same time in karst sloping land.[Conclusion] The research could provide scientific references for the restoration of ecosystem in karst mountainous areas.