不同放牧强度松嫩草地土壤细菌碳代谢指纹差异

Carbon Metabolic Fingerprint of Soil Bacteria Affected by Grazing Intensity in Songnen Steppe

为了探讨放牧强度对松嫩草地土壤细菌功能多样性的影响,利用Biolog-ECO微平板检测技术研究了休牧、适牧、重牧三种不同放牧强度下土壤细菌碳源利用的特征与差异。结果表明:(1)随着培养时间的延长,土壤细菌碳源利用强度逐渐加强并在192h后趋于稳定,证明土壤细菌生物代谢活性逐渐加强;(2)适牧下土壤细菌AWCD、Shannon-Wiener指数、物种丰富度指数、Pielou均匀度指数均最高,休牧次之,重牧最低;(3)适牧处理下的土壤细菌能充分利用碳水化合物、氨基酸、多聚物、酚酸类及胺类等碳源,休牧处理下的土壤细菌对碳水化合物、氨基酸及多聚物能够充分利用,而重牧处理下的土壤细菌只对羧酸类碳源利用有相对优势,三种放牧强度土壤细菌碳代谢指纹顺序为适牧>休牧>重牧;(4)根据RDA分析得出:土壤pH、有机质和全氮是影响松嫩草地土壤细菌碳源利用的主要因素。

In order to explore the effects of different grazing intensities on functional diversity of soil bacteria,the Biolog-ECO technology was used for researching the differences of carbon source utilization of soil bacteria in no grazing,conservative grazing and heavy grazing.The results showed that carbon source utilization rates of soil bacteria increased with cultural time and steadied after 192 hours.In light grazing,the AWCD（the average well color development）,Shannon-Winner index,Richness and Pielou evenness index were all higher than other grazing intensities,and it was the lowest in heavy grazing plots.Carbohydrate,amino acid,polymeric substance,phenolic acid and amine were used by soil bacteria in light grazing plots,carbohydrate,amino acid and polymeric substance were used in no grazing plot,however,only carboxylic acids were well used in heavy grazing.It showed that carbon metabolic fingerprint of soil bacteria in 3grazing intensities as follows：conservative grazing 〉no grazing 〉 heavy grazing.Soil pH,soil organic matter,and total N were major factors influencing the carbon source utilization of soil bacteria in Songnen steppe.