中文摘要：

采用BIOLOG检测法,研究丛枝菌根与黄土高原不同树龄刺槐人工林及次生林根际微生物群落多样性的关系。结果表明：8、15、23和30年刺槐人工林随着树龄的增加,菌根侵染率先增加后降低,微生物活性（AWCD值）增大,碳源代谢丰富度指数（S）和Shannon指数（H）逐渐增加,23年达到峰值后趋于稳定,并逐渐降低,不同林地菌根侵染率与根瘤数呈显著正相关（y=414.82x-188.73,r=0.927,p〈0.05）。主成分分析表明：刺槐人工林根际微生物群落结构与功能随着树龄的增加存在时间上的连续性,次生林优于相同树龄人工林,在碳源利用上表现为与树龄更长的人工林相近。菌根侵染率与根瘤数、细菌量、丰富度指数（S）和Shannon指数（H）的相关性分析表明：丛枝菌根对刺槐根际微生物群落的稳定和功能多样性的增加具有促进作用,在造林年限上表现为对较短树龄刺槐林根际微生物群落影响较大,在造林措施上对刺槐次生林微生物群落多样性的作用优于人工林。

英文摘要：

The relationship of mycorrhizae and diversity of microbial community in rhizosphere soils of Robinia pseudoacacia plantation and secondary plantation at different ages on the Loess Plateau was measured with by BIOLOG method. It was found that in 8, 15, 23 and 30 a plantation forestland, with the age increased, the mycorrhizal infection rate increased at the early stage and then declined. The average well color development （AWCD） increased. The richness index（S） and the Shannon index （H） increased at the early stage and reached to peak value at 23 a and then gradually declined, The mycorrhizal infection rate were significantly correlated with the number of nodules were significant correlation （y = 414.82x - 188.73, r = 0.927, p 〈 0.05） in different forestlands. The principal component analysis showed that with the ages increased, the microbial community structure and function in rhizosphere soils of R. pseudoacacia plantation existed continuity of the time. The secondary forest perfomed better than the same age plantation, and its capacity of carbon utilization was similar to that of the older plantation. The correlation analysis of the mycorrhizal infection rate and the number of nodules, the number of bacteria colonies, the richness index（ S）, the Shannon index （H） indicated that, the arbuscular mycorrhizae promoted the stabilization and function diversity of microbial community in rhizosphere soils of R. seudoacacia. The mycorrhizae influenced more significantly the microbial community of younger R. pseudoacacia plantation in terms of afforestation time and it had more remarkable effects on diversity of microbial community of secondary forest than R. pseudoacacia plantation with regard of afforestation measures.