Distribution and drivers of ectomycorrhizal fungal communities across the North American Arctic

• Published in: Ecosphere
• Main Authors: Timling, Ina, Dahlberg, Anders, Walker, Donald A., Gardes, Monique, Charcosset, Jean-Yves, Welker, Jeffrey M., Taylor, D. Lee
• Other Authors: University of Alaska Fairbanks (UAF), Uppsala University, Evolution et Diversité Biologique (EDB), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: Species richness; Arctic; Bioclimatic subzone; Community structure; Dryas integrifolia; Environmental drivers; Ectomycorrhizal fungi; Host specificity; Latitudinal gradient; Salix arctica; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; [SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology
• Online Access: https://hal.archives-ouvertes.fr/hal-00960017; https://hal.archives-ouvertes.fr/hal-00960017/document; https://hal.archives-ouvertes.fr/hal-00960017/file/timpling_11124.pdf; https://doi.org/10.1890/ES12-00217.1

International audience Ectomycorrhizal fungi (EMF) form symbioses with a few plant species that comprise a large fraction of the arctic vegetation. Despite their importance, the identity, abundance and distribution of EMF in the Arctic, as well as the key drivers controlling their community composition are poorly understood. In this study, we investigated the diversity and structure of EMF communities across a bioclimatic gradient spanning much of the North American Arctic.We collected roots from two principal arctic ectomycorrhizal host plants, Salix arctica and Dryas integrifolia, typically growing intermingled, at 23 locations stratified across the five bioclimatic subzones of the Arctic. DNA was extracted from ectomycorrhizal root tips and the ITS region was sequenced and phylogenetically analyzed. A total of 242 fungal Operational Taxonomic Units (OTUs) were documented, with 203 OTUs belonging to the Basidiomycota and 39 to the Ascomycota, exceeding the number of previously morphologically described EMF in the Arctic. EMF communities were dominated by a few common and species-rich families such as Thelephoraceae, Inocybaceae, Sebacinaceae, Cortinariaceae, and Pyronemataceae. Both host plants showed similar species richness, with 176 OTUs on Salix arctica and 154 OTUs on Dryas integrifolia. Host plant identity did not affect EMF community composition. The ten most abundant OTUs had a wide geographic distribution throughout the Arctic, and were also found in boreal, temperate and Mediterranean regions, where they were associated with a variety of hosts. Species richness did not decline with increasing latitude. However, EMF community structure changed gradually across the bioclimatic gradient with the greatest similarity between neighboring bioclimatic subzones and locations. EMF community structure was correlated with environmental factors at a regional scale, corresponding to a complex of glaciation history, geology, soil properties, plant productivity and climate. This is the first large-scale study of ...