Biomass and compositional responses of ectomycorrhizal fungal hyphae to elevated CO2 and nitrogen fertilization

Authors

  • Jeri Lynn Parrent,

    1. Biology Department, Duke University, Box 90338, Durham, NC 27708-0338, USA;
    2. (Present address) Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, PO Box 7026, Ulls väg 26a, SE 750 07 Uppsala, Sweden
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  • Rytas Vilgalys

    1. Biology Department, Duke University, Box 90338, Durham, NC 27708-0338, USA;
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Author for correspondence: Jeri Lynn Parrent Tel: +46 (0) 18 67 27 29 Fax: +46 (0) 18 67 35 99 Email: Jeri.Parrent@mykopat.slu.se

Summary

  • • The extramatrical mycelia (EMM) of ectomycorrhizal fungi make up a large proportion of the microbial diversity and biomass in temperate forest soils. Thus, their response to elevated CO2 can have large effects on plant nutrient acquisition and carbon movement through forests.
  • • Here, the effects of CO2 and nitrogen (N) fertilization on EMM biomass and community structure in Pinus taeda forest plots were examined using sand-filled mesh bags buried in the field, the contents of which were analyzed by phospholipid fatty acid (PLFA) and DNA sequencing.
  • • A total of 2138 sequences comprising 295 taxa were recovered; most (83.5%) were from ectomycorrhizal fungal taxa. No biomass increase was detected in elevated CO2 plots relative to control plots, but individual taxa responded to both CO2 and N fertilization, four of the six most abundant taxa were less frequent in N-fertilized plots. Thelephoroid and athelioid taxa were both frequent and abundant as EMM, and thelephoroid richness was extremely high. Russula and Cortinariaceae taxa were less abundant and boletoid taxa were more abundant as EMM relative to ectomycorrhizas.
  • • The EMM community, sampled across seasons and years, was dynamic with a high degree of interspecific variation in response to CO2 enrichment and N fertilization.

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