喀斯特高原退化湿地草海土壤微生物群落碳源代谢活性研究

为了揭示土壤微生物群落功能多样性对湿地退化过程的响应及其与环境因子的关系,采用BIOLOG-ECO微平板法对喀斯特高原湿地草海不同植被演替阶段根际土壤微生物的碳源代谢活性进行了研究.结果表明,沿湿地植被演替梯度,根际土壤微生物群落碳源代谢强度逐渐增加,原生湿地竹叶眼子菜(Comm.Potamogeton malaianu)根际土壤微生物碳源利用能力最低,碳源代谢类型单一;草甸灯芯草(Juncus effusus L.)群落利用能力最强,碳源代谢类型丰富;Shannon指数(H')和Mc Intosh指数(U)均沿植被演替梯度逐渐升高,这可能与地上植物和土壤理化环境变化有关;主成分分析(PCA)提取的3个主成分累计贡献率为92.85%,能够很好解释不同阶段碳源利用的分异,醇类和氨基酸类是引起碳源利用分异的主要基质;冗余分析(RDA)表明,环境因子对微生物碳源代谢活性具有重要影响,p H、DOC是引起碳源利用分异的主要环境因子.土壤微生物群落碳源代谢活性影响湿地碳循环功能.

Carbon metabolic soil microbial community in Caohai Karst Plateau degraded wetland: A case study in southwest China

BIOLOG method was employed to reveal the relationship between the functional diversity of microbial communities and the wetland degradation and to understand the relationship between the diversity of functional microbial communities and environmental factors. The results showed that the carbon metabolic rate of microbes in rhizosphere soil increased along with the community succession of wetland vegetation. The carbon metabolic ability of microbe in rhizosphere of the native plant Comm. Potamogeton malaian was the lowest, with a monotonous metabolic type. The carbon metabolic ability of microbe in rhizosphere of Juncus effusus L. was the highest, with rich metabolic types. Shannon index(H') and McIntosh index(U) rose gradually along with the succession of vegetation, which might be associated with surface plant species and the physicochemical changes of soil environment. Principal component analysis(PCA) was performed to extract three principal components, of which the cumulative contribution was 92.85%. The main substrates led to the variation of carbon metabolic rate are alcohols and amino acids. Redundancy analysis(RDA) showed that environmental factors(mainly, pH and DOC) had a significant effect on carbon metabolic rate of microbes. The changes in functional diversity of wetland soil microbes greatly influenced the function of carbon cycling.