Community composition of arbuscular mycorrhizal fungi in Ontario tallgrass prairies of differing disturbance histories.

Arbuscular mycorrhizal fungi (AMF), in the phylum Glomeromycota, form symbiotic relationships with most vascular plants, including grasses. Tallgrass prairies (TGPs) are an endangered habitat in Ontario; some undisturbed fragments remain and there have been efforts to restore disused agricultural land to prairie. The objective of this study was to investigate differences in the community composition of arbuscular mycorrhizal fungi between disturbed and undisturbed TGP at five locations across southwestern Ontario. The V4 variable region of the small ribosomal subunit was amplified from DNAs extracted from soil samples, and sequence analysis yielded operational taxonomic units (OTUs) representing twelve genera of Glomeromycota. There was a significant difference in the community composition of the AMF communities in undisturbed TGP remnants and restored TGP that had been previously disturbed, with an overall greater community diversity and evenness in the undisturbed than previously disturbed sites. Ambispora fennica, three OTUs of Diversispora and four OTUs of Glomus were found to be potential indicator taxa of undisturbed TGPs and, overall, Glomus was significantly more abundant in undisturbed than disturbed sites. In contrast, two other OTUs of Diversispora, two of Entrophospora and one of Septoglomus were found to be potential indicator taxa of disturbed TGPs. These findings have implications for success of TGP restoration and should be considered in future efforts.