Arbuscular mycorrhizal fungi as mediators of ecosystem responses to nitrogen deposition: A trait-based predictive framework

作者：Treseder Kathleen K; Allen Edith B; Egerton Warburton Louise M; Hart Miranda M; Klironomos John N; Maherali Hafiz; Tedersoo Leho

来源：Journal of Ecology, 2018, 106(2): 480-489.

DOI：10.1111/1365-2745.12919

<jats:title>Abstract</jats:title><jats:p>
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<jats:list-item><jats:p>Anthropogenic nitrogen (N) deposition is exposing plants and their arbuscular mycorrhizal fungi (<jats:styled-content style="fixed-case">AMF</jats:styled-content>s) to elevated N availability, often leading to shifts in communities of <jats:styled-content style="fixed-case">AMF</jats:styled-content>. However, physiological trade‐offs among <jats:styled-content style="fixed-case">AMF</jats:styled-content> taxa in their response to N enrichment vs the ability to acquire other soil nutrients could have negative effects on plant and ecosystem productivity. It follows that information on the functional traits of <jats:styled-content style="fixed-case">AMF</jats:styled-content> taxa can be used to generate predictions of their potential role in mediating ecosystem responses to N enrichment.</jats:p></jats:list-item>

<jats:list-item><jats:p>Arbuscular mycorrhizal fungi taxa that produce extensive networks of external hyphae should forage for N and phosphorus (P) more effectively, but these services incur greater carbon (C) costs to the plant. If N enrichment ameliorates plant nutrient limitation, then plants may reduce C available for <jats:styled-content style="fixed-case">AMF</jats:styled-content>, which in turn could eliminate <jats:styled-content style="fixed-case">AMF</jats:styled-content> taxa with large extensive external hyphae from the soil community. As a result, the remaining <jats:styled-content style="fixed-case">AMF</jats:styled-content> taxa may confer less P benefit to their host plants.</jats:p></jats:list-item>

<jats:list-item><jats:p>Using a synthesis of data from the literature, we found that the ability of a taxon to persist in the face of increasing soil N availability was particularly high in isolates from the genus <jats:italic>Glomus</jats:italic>, but especially low among the Gigasporaceae. Across <jats:styled-content style="fixed-case">AMF</jats:styled-content> genera, our data support the prediction that <jats:styled-content style="fixed-case">AMF</jats:styled-content> with a tolerance for high soil N may confer a lower P benefit to their host plant. Relationships between high N tolerance and production of external hyphae were mixed.</jats:p></jats:list-item>

<jats:list-item><jats:p><jats:italic>Synthesis</jats:italic>. If the relationship between N tolerance and plant P benefit is widespread, then shifts in arbuscular mycorrhizal fungi communities associated with N deposition could have negative consequences for the ability of plants to acquire P and possibly other nutrients via a mycorrhizal pathway. Based on this relationship, we predict that arbuscular mycorrhizal fungi responses could constrain net primary productivity in P‐limited ecosystems exposed to N enrichment. This prediction could be tested in future empirical and modelling studies.</jats:p></jats:list-item>
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• 出版日期2018-3