Journal Article

Grazing-induced microbiome alterations drive soil organic carbon turnover and productivity in meadow steppe

Jin, Dongyan, Zhang, Guishan, Yan, Ruirui, Xiong, Wu, Ren, Yi, Xin, Xiaoping, Cui, Zhongli, Xun, Weibing, Zhang, Ruifu

2018

Overview

Background Grazing is a major modulator of biodiversity and productivity in grasslands. However, our understanding of grazing-induced changes in below-ground communities, processes, and soil productivity is limited. Here, using a long-term enclosed grazing meadow steppe, we investigated the impacts of grazing on the soil organic carbon (SOC) turnover, the microbial community composition, resistance and activity under seasonal changes, and the microbial contributions to soil productivity. Results The results demonstrated that grazing had significant impacts on soil microbial communities and ecosystem functions in meadow steppe. The highest microbial α-diversity was observed under light grazing intensity, while the highest β-diversity was observed under moderate grazing intensity. Grazing shifted the microbial composition from fungi dominated to bacteria dominated and from slow growing to fast growing, thereby resulting in a shift from fungi-dominated food webs primarily utilizing recalcitrant SOC to bacteria-dominated food webs mainly utilizing labile SOC. Moreover, the higher fungal recalcitrant-SOC-decomposing activities and bacterial labile-SOC-decomposing activities were observed in fungi- and bacteria-dominated communities, respectively. Notably, the robustness of bacterial community and the stability of bacterial activity were associated with α-diversity, while this was not the case for the robustness of fungal community and its associated activities. Finally, we observed that microbial α-diversity rather than SOC turnover rate can predict soil productivity. Conclusions Our findings indicate the strong influence of grazing on soil microbial community, SOC turnover, and soil productivity and the important positive role of soil microbial α-diversity in steering the functions of meadow steppe ecosystems.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Animals / Bacteria / Bacteria - classification / Bacteria - genetics / Bacteria - isolation & purification / Bacteria - metabolism / Biodiversity / Biogeography / Bioinformatics / Biomedical and Life Sciences / Biomedicine / Carbon / Carbon - metabolism / Cattle grazing / Community composition / Decomposition / Ecosystems / Environmental aspects / Feeding Behavior / Food webs / Fungi / Fungi - classification / Fungi - genetics / Fungi - isolation & purification / Fungi - metabolism / Genetic aspects / Grasslands / Grazing / Livestock - physiology / Medical Microbiology / Microbial composition / Microbial Ecology / Microbial Genetics and Genomics / Microbiology / Microbiomes / Microbiota / Microbiota (Symbiotic organisms) / Nitrogen - metabolism / Organic carbon / Organic soils / Productivity / Respiration / RNA sequencing / Seasonal variations / SOC-decomposition enzymatic activity / Soil - chemistry / Soil fertility / Soil incubation / Soil Microbiology / Soil microorganisms / Soil productivity / Steppes / Studies / Temperate meadow steppe / Vegetation / Virology