内蒙古贝加尔针茅草原不同利用方式土壤微生物功能多样性

基于Biolog-ECO技术,研究了贝加尔针茅草原在自由放牧、刈割和围封3种不同利用方式下土壤微生物群落功能多样性变化。结果表明:不同的利用方式能显著改变土壤微生物群落代谢活性,反映微生物活性的平均颜色变化率表现为围封>自由放牧>刈割,围封时土壤微生物群落代谢活性最高;不同的利用方式改变了土壤微生物群落多样性指数,自由放牧土壤微生物群落丰富度指数、均匀度指数和优势度指数均最高,围封次之,刈割最低。主成分分析结果表明:在自由放牧和刈割2种利用方式下土壤微生物群落碳源利用模式及代谢功能相似,而围封土壤微生物群落具有不同的碳源利用模式和代谢功能;糖类、氨基酸类和代谢中间产物及次生代谢物为土壤微生物利用的主要碳源。不同的利用方式改变了贝加尔针茅草原土壤微生物群落功能多样性。

Functional diversity of soil microbial communities in Stipa baicalensis steppe in Inner Mongolia as affected by different land use patterns

By using Biolog-ECO technique, this paper studied the variations of the functional diversity of soil microbial communities in Stipa baicalensis steppe under effects of different land use patterns (grazing, mowing, and fencing). Different land use patterns changed the metabolic activities of the soil microbial communities significantly. The average well color development which directly reflected the microbial activities changed in the order of fencing > grazing > mowing. Under the effects of the land use patterns, the diversity indices of the microbial communities varied. The richness index (H), evenness index (E), and dominance index (D) were the highest under grazing, followed by under fencing and mowing. The principal component analysis (PCA) showed that the carbon source utilization mode and metabolic function of the microbial communities were similar under grazing and mowing, but differed from those under fencing. Carbohydrates, amino acids, intermediate metabolites, and secondary metabolites were the main carbon sources utilized by the microbial communities. This study showed that different land use patterns changed the functional diversity of the soil microbial communities in the Stipa baicalensis steppe in Inner Mongolia.