黄河源区高寒草甸沙漠化土壤碳氮的衰减特征

以甘肃省甘南地区玛曲县高寒草甸沙漠化典型地区的山坡中部和山前平地为例，对其不同沙漠化阶段土壤的有机碳、全氮含量进行了测定与分析。研究结果表明:土壤沙漠化过程中有机碳、全氮含量的衰减呈规律性变化，土壤中有机碳与全氮比值呈递减趋势，且不同沙漠化阶段土壤中有机碳含量的衰减速率快于全氮含量的衰减速率。

Characteristics of Soil C and N Losses during Desertification at Alpine Meadow in Source Region of Yellow River

In relation to middle hillside and piedmont plain in the typical desertification area of alpine meadow in Maqu County in the south of Gansu, the contents of organic carbon and total nitrogen in the soil in different stages of desertification was determined and analyzed. The study result shows that losses of the organic carbon and the total nitrogen during desertification of soil changes regularly, the ratio of the organic carbon to the nitrogen in the soil tends to decline, and in different stages of desertification, losing speed of the organic carbon loss is faster than that of the total nitrogen.