中文摘要：

通过实地调查及平板表面涂抹法和稀释法分别测定了5种不同扰动生境（一年生草地、多年生草地、围栏内草地、围栏外草地和“黑土滩”草地）下，高寒生态脆弱区天祝草原植被状况、土壤细菌、真菌、放线菌及总数量的影响。结果表明，不同扰动生境草地植被状况、土壤细菌、真菌、放线菌数量及总数量分布各不相同。其中一年生草地植被盖度、产量最大，土壤细菌及微生物总数量最高；“黑土滩”草地土壤真菌及放线菌数量最多，但植被盖度最小；围栏外草地地上植物量最小，土壤细菌、真菌、放线菌及微生物总数量最低。该区草地退化和土壤微生物数量减少的趋势并未得到改善。因此，应对该区草地和土壤退化给予足够的重视。

英文摘要：

The status of vegetation and the population of three main soil microorganism （fungi, bacteria and actinomycetes） of alpine grassland in Tianzhu county, the vulnerable ecological region, were tested by field survey and colony count in petri dishes. The soil samples were divided into five different typical habitats which are annual artificial grassland, mixed perennial artificial grassland, fenced rangeland, unfenced rangeland and rodent hill. The results obtained as follow： 1） the number of the population of soil microorganism in different habitats changed obviously. The highest of vegetation coverage, phytomass, the population of bacteria and the sum of microorganism in the grassland of was annual artificial grassland. 2） the population of fungi and actinomycetes in rodent hill was the highest but the vegetation coverage was the lowest. 3） The number of the population of bacteria, fungi, actinomycetes, the sum of microorganism and the phytomass in unfenced rangeland was the lowest. The vulnerable ecological region still has the trend of grassland degradation and decreasing of soil microorganism, and no improvement involved. Therefore, more attention should be pay to the grassland degradation and soil degradation in the area.