Abstract
Findings of immense microbial diversity are at odds with observed functional redundancy, as competitive exclusion should hinder coexistence. Tradeoffs between dispersal and competitive ability could resolve this contradiction, but the extent to which they influence microbial community assembly is unclear. Because fungi influence the biogeochemical cycles upon which life on earth depends, understanding the mechanisms that maintain the richness of their communities is critically important. Here, we focus on ectomycorrhizal fungi, which are microbial plant mutualists that significantly affect global carbon dynamics and the ecology of host plants. Synthesizing theory with a decade of empirical research at our study site, we show that competition–colonization tradeoffs structure diversity in situ and that models calibrated only with empirically derived competition–colonization tradeoffs can accurately predict species–area relationships in this group of key eukaryotic microbes. These findings provide evidence that competition–colonization tradeoffs can sustain the landscape-scale diversity of microbes that compete for a single limiting resource.
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Acknowledgements
This research was supported by NSF grant DBI-1249341 to KGP, NSF grants DBI-1046115 and DEB-0742868 to TDB, and DOE grant DE-SC0016097 to KGP. The work of GRS is supported by an NSF Graduate Research Fellowship. We thank EG Mordecai for feedback on an earlier draft of this manuscript, and J Tan and L Kaplan for mathematical assistance.
Author contributions
KGP and TDB designed and carried out the field experiment; GRS, BSS, and KGP analyzed and interpreted the data; GRS, BSS, TDB, and KGP wrote the paper.
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Smith, G.R., Steidinger, B.S., Bruns, T.D. et al. Competition–colonization tradeoffs structure fungal diversity. ISME J 12, 1758–1767 (2018). https://doi.org/10.1038/s41396-018-0086-0
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DOI: https://doi.org/10.1038/s41396-018-0086-0
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