Ecological corridors homogenize plant root endospheric mycobiota

Summary Ecological corridors have been shown to promote species coexistence in fragmented habitats where dispersal limits species fluxes. The corridor concept was developed and investigated mainly by focusing on macroorganisms while microorganisms, the invisible majority of biodiversity, have been disregarded. Combining an experimental corridor-mesocosm design with high-throughput amplicon sequencing, we analyzed the effect of corridors on the dynamics of endospheric fungal assemblages associated with plant roots at metric scale over two years (i.e. at five time points). We show that the plant symbiotic compartment was sensitive to corridor effects when the corridors were set up at a small spatial scale. The endospheric mycobiota of connected plants displayed higher species richness, lower beta-diversity, and a more deterministic assembly than the mycobiota of isolated plants. These effects became more pronounced with the development of host plants. Biotic corridors composed of host plants may thus play a key role in the spatial dynamics of microbial community and may influence microbial diversity and related ecological functions.