Abstract: We have studied on 12 soil biochemical activeties in three degenerative grasslands (Dasiphora fruticosa shrub, Kobresia pygmaea meadow and Festuca sinensis grassland) in northwest Sichuan,China.Results showed that the soil biochemical activities and the correlations between them are influenced differently,and the influence is in accordance with the degree of grassland degeneration.Soil biochemical activities in the grasslands have been decreasing with grassland degeneration, especially Cellulose decomposition, Nitrogon fixation and Protease activities, but they are not all significantly different in other activities, They are also differ in their soil biochemical activities significantly correlated with different ones, The worse degenerative grassland, Festuca sinensis grassland has no such close correlations between 12 soil biochemical activoties as the other do, its interrealtions have been destroyed or changed.

Key words: Degenerative grassland, Soil microorgaism, Biochemical activity

摘要： 通过对三种不同退化程度的退化草地土壤生化活性进行测定和相关性分析,结果表明草地退化后其土壤生化活性受到不同程度的影响,表现为土壤生化活性随着退化程度增高而减小,但差异并非都达到统计学上的显著性,而土壤生化活性间的相关性则显著地与草地退化程度有关,说明退化草地土壤微生物间的协调作用受到显著影响,从而影响土壤氮素和碳素代谢途径。

关键词: 退化草地, 土壤微生物, 生化活性