川西北退化草地土壤微生物生化活性的初步研究

通过对川西北三种不同退化程度的几种土壤的生化活性大小及其相关性进行研究，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，其影响明显地与退化程度有关；土壤生化活性大小有随退化程度增高而减小的趋势，但差异并非都达到统计学上的显著性，而土壤生化活性间地的相关性则显著地与草地退经程度有关，说明退化草地其土壤微生物间的协同作用受到显著影响，从而影响其土壤碳氮循环代途径，降低土壤肥力水平。

PRELIMINARY STUDY ON SOIL BIOCHEMICAL ACTIVITIES OF DEGENERATED GRASSLANDS IN NORTHWESTEKNE SICHUAN CHINA

A study was made on 12 soil biochemical activities in three degenerated grasslands (Dasiphora fruticosa shrub, Kobresia Pygmaea meadow and Festuca sinensis grassland) of the northwestern Sichuan in China. Results show that the soil biochemical activities and the correlations among them were influenced significantly by the degree of grassland degeneration. Soil biochemical activities, especially cellulose de-composition, nitrogen fixation and protease activities, in the grasslands decreased with the degree of grassland, though the differences carer not statistically significant. But the correlations among biochemical activities of the soils were significantly correlated with the degree of grassland degeneration. The worse degrnerative grassland, Festuca sinensis grassland showed no such significant correlations among the 12 soil biochemical activities. Based on the research results considered that the measures for the improvement and amelioration of degenerated grasslands should be adopted according to the soil ecological changes and the correlations among soil biochemical activities.