Effect of plant communities on bacterial, fungal and arbuscular mycorrhizal communities in a Central European grassland

Abstract Background Grasslands provide fundamental ecosystem services that are supported by their plant diversity. However, the importance of plant taxonomic diversity for the diversity of other taxa in grasslands remains an open question. Here, we studied the associations between plant communities, soil chemistry and soil microbiome in wooded meadow of Čertoryje (White Carpathians, Czech Republic), a European hotspot of plant species diversity. Results High plant diversity was associated with treeless grassland patches with high primary productivity and high contents of soil nitrogen and organic carbon. In contrast, low plant diversity occurred in grasslands near solitary trees and forest edges. Fungal communities differed between low-diversity and high-diversity grasslands more strongly than bacterial communities, while the difference in arbuscular mycorrhizal fungi (AMF) depended on their location in soil vs plant roots. High-diversity plant communities had a higher diversity of fungi including soil AMF than grasslands with low plant diversity, different community composition and higher bacterial and soil AMF biomass. Root AMF composition differed only slightly between grasslands with low and high plant diversity. Trees dominated the belowground plant community in low-diversity grasslands, which influenced microbial diversity and composition. Conclusions The determinants of microbiome abundance and composition in grasslands are complex. Soil chemistry mainly influenced bacterial communities, while vegetation mainly affected fungal (including AMF) communities. Further studies on the functional roles of microbial communities are needed to understand plant-soil-microbe interactions and their involvement in grassland ecosystem services.