Abstract: The distribution and correlation of organic carbon and enzyme activities of meadow chestnut soil were studied in the upstream of Heihe of Qilian Mountains. The degraded degree of grassland was classified as non-degraded, light degraded, moderate degraded and heavy degraded grassland. The results showed that the organic carbon contents, densities, reserves and enzyme activities of 0~60 cm soil layer were ordered as non-degraded >light degraded >moderate degraded >heavy degraded grassland. The organic carbon contents of 0~10 cm soil layer were 1.78, 1.98, 1.87 and 2.00 times higher than that of 50~60 cm soil layer in all tested grasslands. The Organic carbon contents, densities, reserves and enzyme activities of all treatments decreased with the increase of soil layer depth. There were significantly positive relationships between organic carbon content and density, enzyme activity.

Key words: Grassland, Alpine shrub meadow soil, Organic carbon, Enzyme activities

摘要： 为揭示草地退化过程中土壤有机碳和酶活性的分布特征及相关性，在祁连山黑河上游俄博岭区域的高山灌丛草甸土上，根据草地退化程度，划分了未退化草地、轻度退化草地、中度退化草地、重度退化草地，采用野外采样室内分析方法，研究了不同退化草地土壤有机碳和酶活性的分布特征。结果表明：4种退化草地0～60 cm土层有机碳的含量、密度、储量，以及土壤酶活性变化顺序为：未退化草地>轻度退化草地>中度退化草地>重度退化草地；4种退化草地（从轻到重）0～10 cm土层有机碳密度是50～60 cm土层有机碳密度的1.78倍、1.98倍、1.87倍和2.00倍，说明土壤有机碳密度在表层具有很强的表聚性；4种退化草地不同土层有机碳的含量、密度和储量，以及土壤酶活性均随着土壤剖面垂直深度的增加而递减；4种退化草地土壤有机碳含量与有机碳密度、土壤酶活性成显著正相关关系。

关键词: 草地, 高山灌丛草甸土, 有机碳, 酶活性