Ectomycorrhizal fungal communities of oak savanna are distinct from forest communities

Abstract

Oak savanna is one of the most endangered ecosystems of North America, with less than 0.02% of its original area remaining. Here we test whether oak savanna supports a unique community of ectomycorrhizal fungi, a higher diversity of ectomycorrhizal fungi or a greater proportional abundance of ascomycete fungi compared with adjacent areas where the absence of fire has resulted in oak savanna conversion to oak forest. The overall fungal community was highly diverse and dominated by Cenococcum geophilum and other ascomycetes, Cortinarius, Russula, Lactarius and Thelephoraceae. Oak savanna mycorrhizal communities were distinct from oak forest communities both aboveground (sporocarp surveys) and belowground (RFLP identification of ectomycorrhizal root tips); however total diversity was not higher in oak savanna than oak forests and there was no evidence of a greater abundance of ascomycetes. Despite not having a higher local diversity than oak forests, the presence of a unique fungal community indicates that oak savanna plays an important role in maintaining regional ectomycorrhizal diversity.

• Ascomycota
• conservation
• diversity
• fire
• habitat loss
• mycorrhizal ecology

Kirk Haskins initiated this experiment, including initial sporocarp surveys and location of sample plots. We thank Susan Barrott, Cindy Buschena, Holly Swanson and Camille Jensen for help with both field and laboratory work. Financial support was provided by the US National Science Foundation Long Term Ecological Research program (NSF/DEB 0080382), a grant from the Graduate School, University of Minnesota, and the Minnesota Agricultural Experiment Station. IAD also was supported by the Foundation for Research, Science and Technology (FRST) of New Zealand during the analysis and writing stage of this research.