中文摘要：

通过生态退化区不同植被恢复类型对土壤微生物种群数量和分布的影响研究，揭示植被恢复过程中土壤微生物种群的变化。结果表明，沙米荒地、白沙蒿、柠条、沙冬青、人工乔木林＋樟子松土壤微生物种群数量和分布明显不同，土壤细菌、真菌、放线菌种群数量差异显著（P〈0．05），细菌种群数量最高，其次为放线菌，真菌种群数量最小。通过主成分分析，影响该保护区土壤三大类微生物种群总数量的主要因子是植被、土壤有机质、pH、土壤速效钾、土壤水分含量、土壤全磷和速效磷、土壤放线菌、土层深度、土壤真菌种群数量和土壤全氮含量。

英文摘要：

The impacts of the restored vegetation on soil microbial population number and distribution were studied from 2005 to 2007, for understanding and identifying the changes of soil microbial population and for revealing the microbial mechanism of ecological restoration. The results showed that the five kinds of vegetation restoration had a significant impact on soil microbial population number and distribution. Among the five kinds of restored vegetation, Agriphyllum squarrosum,Artemisia sphaerocephala krasch, Caragana korshinskii ,Ammopiptanthus mongolicus, artificial arbor（ Robinia pseudoacacia and Pinaceae sylvestris var. mongolicus ） , the differences of soil bacterial, actinomycetic and fungal population number are statistically significant （ P 〈 0.05 ）. Soil bacterial population number was the highest, and soil actinomycetic population number went next, and fungal one was the least. At 0-15 cm layer in soil profiles, both soil bacterial population number and total soil microbial population number in terms of bacteria, actinomyces and fungi was the highest under the restored Ammopiptanthus mongolicus, and fungal and actinomycetic population number was the highest respectively under restored Artemisia sphaerocephala; at 15-30 cm soil bacterial population number was the highest under Caragana korshinskii, while fungal actinomycetic and the total microbial population number was the highest under Artemisia sphaerocephala krasch; at 30-45 cm soil bacterial, fungal and actinomycetic population number and the total microbial population number were the highest under the restored Ammopiptanthus mongolicus. From principal component analysis, the main impacting factors on the total soil microbial population number in the degraded system are vegetation restoration type, soil organic matter content,pH, soil available K, soil water content, both soil total P and available P, soil actinomycetic population number, soil layer depth, soil fungal population number and soil total N content, which covered 74. 036% of the