Salt is a main factor shaping community composition of arbuscular mycorrhizal fungi along a vegetation successional series in the Yellow River Delta

In coastal wetlands, salinity significantly influences the vegetation successional series. Arbuscular mycorrhizal fungal (AMF) are ubiquitous soil microorganisms which play important roles in plant establishment, diversifying plant communities and accelerating successional progress by improving the soil health. However, the structure and function of AMF communities in coastal wetlands are poorly understood. Here we investigated the AMF communities along a vegetation successional series (from intertidal to supratidal flats) and the sediment physicochemical factors affecting the variations. AMF community composition and diversity were analyzed by 18S rRNA genes using high-throughput sequencing technology. The results revealed that the maximum number of AMF sequences belonged to Glomus 74,660, 62.75%. The relative abundance of the top three genera differed significantly along the vegetation successional series. Redundancy analysis (RDA) results demonstrated that salinity was a major environmental factor structuring the AMF community in the sediment along the vegetation successional series. No significant differences of AMF diversity were observed between different sediment layers. Additionally, total nitrogen (TN) and total carbon (TC), important soil nutrients in young emergent wetland ecosystems, also contributed to AMF community structure. The results of this study provide a better understanding of the AMF community and the major factors impacting it along a coastal wetland successional series composed of different vegetation types