Root fungal communities associated with better performance of an invasive spring ephemeral

While invasive plants can form dense infestations capable of suppressing native plants in some habitats, in others, they may be much less dominant. Lesser celandine (Ranunculus ficaria) is an invasive spring ephemeral in the northeastern United States and the Pacific Northwest. One possibility for the differences in performance of R. ficaria in invaded areas is the presence of fungal–root associations. We hypothesized that plant performance (biomass and reproductive output) would be driven by community composition of root-associated fungi. Eight invaded sites with a history of variable plant performance were chosen in Cleveland, Ohio. At each site, eight samples (n = 64) were collected along a transect. Terminal restriction fragment length polymorphism and cloning were used in conjunction to determine differences in the root-associated mycobiota colonizing R. ficaria. Microscopy was used to confirm the presence of structures indicative of root-associated fungi. R. ficaria roots were potential hosts to a diverse group of fungi. R. ficaria colonized by root-associated fungal communities consisting of dark septate endophytes and fungi typically associated with ericoid mycorrhizae had a significantly higher average biomass and bulbil counts than plants colonized by parasitic root mycobiota. However, fungal colonization was not shown to be associated with differences in the number of R. ficaria tubers present. This indicates that fungal community composition and colonization may influence the biomass and bulbil production of R. ficaria, which can be linked to the success of this invasive.