title: Distinct microbial communities associated with buried soils in the Siberian tundra.
abstract: Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze-thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes.
authors: 1] Department of Biology, Centre for Geobiology, University of Bergen, Bergen, Norway [2] Austrian Polar Research Institute, Vienna, Austria.
authors: Antje
authors: 0000000178407861
authors: A
authors: Gittel
authors: Department of Ecosystems Biology, University of South Bohemia, České Budějovice, Czech Republic.
authors: Jiří
authors: J
authors: Bárta
authors: Department of Ecosystems Biology, University of South Bohemia, České Budějovice, Czech Republic.
authors: Iva
authors: I
authors: Kohoutová
authors: Institut für Bodenkunde, Leibniz Universität Hannover, Hannover, Germany.
authors: Robert
authors: R
authors: Mikutta
authors: 1] Institute of Genomics and Systems Biology, Argonne National Laboratory, Argonne, IL, USA [2] Computation Institute, University of Chicago, Chicago, IL, USA.
authors: Sarah
authors: S
authors: Owens
authors: 1] Institute of Genomics and Systems Biology, Argonne National Laboratory, Argonne, IL, USA [2] Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA.
authors: Jack
authors: J
authors: Gilbert
authors: 1] Austrian Polar Research Institute, Vienna, Austria [2] Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
authors: Jörg
authors: J
authors: Schnecker
authors: 1] Austrian Polar Research Institute, Vienna, Austria [2] Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
authors: Birgit
authors: B
authors: Wild
authors: Department of Earth Science, Centre for Geobiology, University of Bergen, Bergen, Norway.
authors: Bjarte
authors: B
authors: Hannisdal
authors: Division of Ecosystem Modelling, Institute of Coastal Research, Helmholtz Zentrum Geesthacht, Geesthacht, Germany.
authors: Joeran
authors: J
authors: Maerz
authors: Central Siberian Botanical Garden, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia.
authors: Nikolay
authors: N
authors: Lashchinskiy
authors: Department of Ecosystems Biology, University of South Bohemia, České Budějovice, Czech Republic.
authors: Petr
authors: P
authors: Capek
authors: Department of Ecosystems Biology, University of South Bohemia, České Budějovice, Czech Republic.
authors: Hana
authors: H
authors: Santrůčková
authors: Institut für Bodenkunde, Leibniz Universität Hannover, Hannover, Germany.
authors: Norman
authors: N
authors: Gentsch
authors: 1] Institut für Bodenkunde, Leibniz Universität Hannover, Hannover, Germany [2] VN Sukachev Institute of Forest, Siberian Branch of Russian Academy of Sciences, Akademgorodok, Russia.
authors: Olga
authors: O
authors: Shibistova
authors: Institut für Bodenkunde, Leibniz Universität Hannover, Hannover, Germany.
authors: Georg
authors: G
authors: Guggenberger
authors: 1] Austrian Polar Research Institute, Vienna, Austria [2] Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.
authors: Andreas
authors: A
authors: Richter
authors: Department of Biology, Centre for Geobiology, University of Bergen, Bergen, Norway.
authors: Vigdis L
authors: VL
authors: Torsvik
authors: 1] Department of Biology, Centre for Geobiology, University of Bergen, Bergen, Norway [2] Austrian Polar Research Institute, Vienna, Austria [3] Division of Archaea Biology and Ecogenomics, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.
authors: Christa
authors: C
authors: Schleper
authors: 1] Austrian Polar Research Institute, Vienna, Austria [2] Division of Archaea Biology and Ecogenomics, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.
authors: Tim
authors: T
authors: Urich
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics / Q000502:physiology*; D001419:Bacteria / Q000145:classification / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D044822:Biodiversity; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D017753:Ecosystem; D004798:Enzymes / Q000378:metabolism; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000502:physiology*; D020459:Genes, rRNA / Q000235:genetics; D012800:Siberia; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D021903:DNA, Ribosomal Spacer; D004798:Enzymes; D012987:Soil