玛曲高寒草地沙化对土壤理化特性的影响

以玛曲高寒草地处于不同沙化发展阶段的潜在沙化地、轻度沙化地、中度沙化地和重度沙化地为研究对象,阶地作为对照,对0～60 cm土壤剖面的机械组成和土壤有机碳、全氮、全磷以及速效钾含量进行了测定,分析结果表明:1)随草地沙化程度的加剧,不同类型沙化草地的黏粒和粉粒含量迅速下降,细砂粒含量逐渐下降而粗砂粒含量逐渐上升。2)随草地沙化程度的加剧,不同程度沙化草地的有机碳和全N含量呈逐渐下降趋势。3)从不同程度沙化草地各层土壤的养分含量来看,阶地和潜在沙化地各土层有机碳和全N含量随土层深度加深逐渐下降,中度沙化地、重度沙化地各土层有机碳和全N含量呈现基本稳定的状态。

The impact of grassland desertification to soil characteristics in Maqu

The grassland,terrace,potential sandy grassland,slight sandy grassland,moderate sandy grassland and very severe sandy grassland in Maqu alpine were chosen for sample fields.Mechanical composition and nutrient content in 60 cm layers soil profile were analyzed.It showed that:(1) Clay and silt contents of different sandy grassland types decreased rapidly,fine sand decreased gradually and coarse sand content increased gradually with aggravation of sandy degree.(2) Soil organic carbon and total N content decreased gradually with aggravation of sandy degree.(3) Soil organic carbon and total N of every layer on terrace and potential sandy grassland decreased gradually with increasing of soil depth.Soil organic carbon and total N of every layer on slight sandy grassland,moderate sandy grassland and very severe sandy grassland were in the basically stable situation.