Mycorrhizal fungal communities in coastal sand dunes and heaths investigated by pyrosequencing analyses

Maritime sand dunes and coastal ericaceous heaths are unstable and dynamic habitats for mycorrhizal fungi. Creeping willow (Salix repens) is an important host plant in these habitats in parts of Europe. In this study, we wanted to assess which mycorrhizal fungi are associated with S. repens in four different coastal vegetation types in Southern Norway, three types from sand dunes and one from heaths. Moreover, we investigated which ecological factors are important for the fungal community structure in these vegetation types. Mycorrhizal fungi on S. repens root samples were identified by 454 pyrosequencing of tag-encoded internal transcribed spacer 1 (ITS1) amplicons. Significantly higher fungal richness was observed in hummock dunes and dune slacks compared to eroded dune vegetation. The compositional variation was mainly accounted for by location (plot) and vegetation type and was significantly correlated to content of carbon, nitrogen and phosphorus in soil. The investigated maritime sand dunes and coastal ericaceous heaths hosted mycorrhizal taxa mainly associated with Helotiales, Sebacinales, Thelephorales and Agaricales.