Long-term mowing reinforces connections between soil microbial and plant communities in a temperate steppe

Purpose Mowing is an important management practice in the Inner Mongolia grassland and can significantly regulate plant and soil microbial communities. However, impact of long-term mowing on soil microbiota has been rarely evaluated in grassland ecosystems, and the effects of plant community on belowground microbiota under mowing were mainly focused on plant α-diversity, while the role of plant β-diversity is largely unknown. Methods We examined the soil bacterial, fungal and protistan communities under the influence of a 17-year mowing treatment in a natural grassland of Inner Mongolia, and studied the relationship between the soil microbial communities and plant/soil parameters, and the correlations between β-diversity of the soil microbial and plant communities. We also constructed co-occurrence networks to investigate the legacy of mowing on the interactions between plant community and the three microbial groups (bacteria, fungi, protists). Results We found that long-term mowing had significant effects on the community structures of plants and the three microbial groups. The microbial community structures mainly correlated to the plant parameters including aboveground biomass, plant litter, root carbon-to-nitrogen ratio, and plant Shannon index rather than to soil properties. Moreover, β-diversity of the soil microbial communities was significantly regulated by plant community β-diversity. Furthermore, mowing enhanced plant-microbe interactions in the networks under long-term mowing. Conclusions Long-term mowing significantly alters plant and soil microbial community compositions and can reinforce their connections. The induced shifts of plant community attributes by long-term mowing rather than soil properties may be more effective factors in shaping soil microbial communities in grasslands.