Ericoid mycorrhizal colonization and associated fungal communities along a wetland gradient in the Acadian forest of Eastern Canada

Wetlands provide numerous ecosystem services, and ericaceous plants are important components of these habitats. However, the ecology of fungi associated with ericaceous roots in these habitats is poorly known. To investigate fungi associated with ericaceous roots in wetlands, ericoid mycorrhizal colonization was quantified, and fungal communities were characterized on the roots of Gaultheria hispidula and Kalmia angustifolia along two upland – forested wetland transects in spring and fall. Ericoid mycorrhizal colonization was significantly higher in the wetlands for both plant species. Both upland and wetland habitats supported distinct assemblages of ericaceous root associated fungi including habitat specific members of the genus Serendipita. Habitat was a stronger driver of ericoid mycorrhizal colonization and ericaceous root associated community composition than host or sampling season, with differences related to soil water content, soil nutrient content, or both. Our results indicate that ericaceous plant roots in forested wetlands are heavily colonized by habitat specific symbionts.