Fungi in the future: interannual variation and effects of atmospheric change on arbuscular mycorrhizal fungal communities

<jats:title>Summary</jats:title><jats:p> <jats:list list-type="bullet"> <jats:list-item><jats:p>Understanding the natural dynamics of arbuscular mycorrhizal (<jats:styled-content style="fixed-case">AM</jats:styled-content>) fungi and their response to global environmental change is essential for the prediction of future plant growth and ecosystem functions. We investigated the long‐term temporal dynamics and effect of elevated atmospheric carbon dioxide (<jats:styled-content style="fixed-case">CO</jats:styled-content><jats:sub>2</jats:sub>) and ozone (O<jats:sub>3</jats:sub>) concentrations on <jats:styled-content style="fixed-case">AM</jats:styled-content> fungal communities.</jats:p></jats:list-item> <jats:list-item><jats:p>Molecular methods were used to characterize the <jats:styled-content style="fixed-case">AM</jats:styled-content> fungal communities of soybean (<jats:italic>Glycine max</jats:italic>) grown under elevated and ambient atmospheric concentrations of both <jats:styled-content style="fixed-case">CO</jats:styled-content><jats:sub>2</jats:sub> and O<jats:sub>3</jats:sub> within a free air concentration enrichment experiment in three growing seasons over 5 yr.</jats:p></jats:list-item> <jats:list-item><jats:p>Elevated <jats:styled-content style="fixed-case">CO</jats:styled-content><jats:sub>2</jats:sub> altered the community composition of <jats:styled-content style="fixed-case">AM</jats:styled-content> fungi, increasing the ratio of Glomeraceae to Gigasporaceae. By contrast, no effect of elevated O<jats:sub>3</jats:sub> on <jats:styled-content style="fixed-case">AM</jats:styled-content> fungal communities was detected. However, the greatest compositional differences detected were between years, suggesting that, at least in the short term, large‐scale interannual temporal dynamics are stronger mediators than atmospheric <jats:styled-content style="fixed-case">CO</jats:styled-content><jats:sub>2</jats:sub> concentrations of <jats:styled-content style="fixed-case">AM</jats:styled-content> fungal communities.</jats:p></jats:list-item> <jats:list-item><jats:p>We conclude that, although atmospheric change may significantly alter <jats:styled-content style="fixed-case">AM</jats:styled-content> fungal communities, this effect may be masked by the influences of natural changes and successional patterns through time. We suggest that changes in carbon availability are important determinants of the community dynamics of <jats:styled-content style="fixed-case">AM</jats:styled-content> fungi.</jats:p></jats:list-item> </jats:list> </jats:p>