中文摘要：

通过对科尔沁沙地五种典型灌木（小叶锦鸡儿、小红柳、差巴嘎蒿、达乌里胡枝子和冷蒿）根际与非根际土壤微生物的研究表明,根际土壤微生物数量远高于非根际土壤,差异显著。五种灌木根际细菌和放线菌数量表现为：差巴嘎蒿〉小红柳〉小叶锦鸡儿〉冷蒿〉达乌里胡枝子;真菌为：小叶锦鸡儿〉小红柳〉差巴嘎蒿〉达乌里胡枝子〉冷蒿。灌木根际细菌所占微生物总数的比例高于非根际,放线菌所占比例较低。五种灌木微生物根际效应R/S：小红柳〉冷蒿〉差巴嘎蒿〉达乌里胡枝子〉小叶锦鸡儿。根际效应R/S是比根际微生物数量更好的反映沙地灌木对根际微生物影响的指标,它从根际与非根际两方面综合对土壤进行评价,具有更深刻的研究意义。

英文摘要：

Rhizospheric and non -rhizospheric microorganisms at five different shrubs of Caragana microphylla （CM）, Salix microstachya （SM）, Artemisia halodendron （AH）, Lespedeza davurica （LD）, Artemisia frigida （AF） in Horqin sandy land were studied. Results showed that microbial populations, including bacteria, actino- myces and fungi, were higher at rhizosphere than at non - rhizosphere, and their difference were significant. Rhizospheric bacterial and actinomycetic population showed： AH 〉 SM 〉 CM 〉 AF 〉 LD, and rhizospheric fungal population revealed ： CM 〉 SM 〉 AH 〉 LD 〉 AF. The proportion of bacteria was higher at rhizosphere than that at non - rhizosphere, and the proportion of actinomyces exhibited a reverse pattern. Rhizosphere effect （R/S） of total microbial population showed： SM 〉 AF 〉 AH 〉 LD 〉 CM. Rhizosphere effect （R/S） of mi- croorganism was a better indicator than rhizosphere microbial population in studying the effect of shrub root sys- tem to soil microorganisms in sandy land, for it can evaluate soil quality in both rhizospheric and non - rhizos- pheric aspects, and R/S is more fundamental in studying shrub root activity in sandy land.