松嫩草地豆类草群落土壤细菌碳源利用研究

利用Biolog-ECO微平板培养技术，探讨松嫩草地兴安胡枝子（Lespedeza daurica）和草木犀（Melilotus officinalis）两种豆类草群落与羊草（Leymus chinensis）群落土壤微生物在碳源利用上的差异。结果表明：兴安胡枝子群落土壤细菌对碳源的利用程度最好，草木犀群落和羊草群落土壤细菌对碳源利用情况较低且接近。糖类和氨基酸在不同植物群落土壤中均得到较好利用，但胺类均较差，兴安胡枝子群落土壤细菌利用碳源的种类和数量最多。兴安胡枝子群落的Shannon-wiener指数，Pielou均匀度指数以及Gini多样性指数最高，羊草次之，草木犀群落最低。对不同植物群落土壤细菌群落功能多样性与土壤理化因子的RDA分析表明，土壤中有机质和全氮含量对3种植物群落土壤细菌的代谢功能及活性影响最大。

Utilization of Carbon Sources by Soil Bacteria in Different Leguminous Communities of Songnen Steppe

In order to study the relationship between plant communities and soil microbial communities in grassland, the method of Biolog-ECO was used in analysis of the carbon source utilization of soil bacteria in different Leguminous communities (Leymus chinensis, Melilotus officinalis and Lespedeza daurica) of Songnen steppe. The results showed that the structure and composition of the 3 plant communities were different, and both the characteristic of plant communities and bacteria metabolic activity and the carbon source utilization were different; Carbon source utilization of soil bacteria community was the hightest in L. daurica community and the lowest in M. officinalis and L. chinensis community, which were close. Carbohydrate and amino acids were better used by soil bacteria in the 3 plant communities, however, amines were poorly used by them. The Shannon-Wiener index, Pielou index, and the Gini index were the highest in L. daurica, the next in L. chinensis and the lowest in M. officinalis. RDA analysis showed that Total N and Organic matter were the major factors on carbon source utilization of soil bacteria in the 3 plant communities.