Temperature response of permafrost soil carbon is attenuated by mineral protection
Jazyk angličtina Země Anglie, Velká Británie Médium print-electronic
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
29774972
DOI
10.1111/gcb.14316
Knihovny.cz E-zdroje
- Klíčová slova
- carbon mineralization, incubation, mineral-organic association, permafrost soils, radiocarbon, temperature sensitivity,
- MeSH
- klimatické změny MeSH
- minerály analýza MeSH
- permafrost * MeSH
- půda chemie MeSH
- teplota * MeSH
- uhlík analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Arktida MeSH
- Sibiř MeSH
- Názvy látek
- minerály MeSH
- půda MeSH
- uhlík MeSH
Climate change in Arctic ecosystems fosters permafrost thaw and makes massive amounts of ancient soil organic carbon (OC) available to microbial breakdown. However, fractions of the organic matter (OM) may be protected from rapid decomposition by their association with minerals. Little is known about the effects of mineral-organic associations (MOA) on the microbial accessibility of OM in permafrost soils and it is not clear which factors control its temperature sensitivity. In order to investigate if and how permafrost soil OC turnover is affected by mineral controls, the heavy fraction (HF) representing mostly MOA was obtained by density fractionation from 27 permafrost soil profiles of the Siberian Arctic. In parallel laboratory incubations, the unfractionated soils (bulk) and their HF were comparatively incubated for 175 days at 5 and 15°C. The HF was equivalent to 70 ± 9% of the bulk CO2 respiration as compared to a share of 63 ± 1% of bulk OC that was stored in the HF. Significant reduction of OC mineralization was found in all treatments with increasing OC content of the HF (HF-OC), clay-size minerals and Fe or Al oxyhydroxides. Temperature sensitivity (Q10) decreased with increasing soil depth from 2.4 to 1.4 in the bulk soil and from 2.9 to 1.5 in the HF. A concurrent increase in the metal-to-HF-OC ratios with soil depth suggests a stronger bonding of OM to minerals in the subsoil. There, the younger 14 C signature in CO2 than that of the OC indicates a preferential decomposition of the more recent OM and the existence of a MOA fraction with limited access of OM to decomposers. These results indicate strong mineral controls on the decomposability of OM after permafrost thaw and on its temperature sensitivity. Thus, we here provide evidence that OM temperature sensitivity can be attenuated by MOA in permafrost soils.
5 N Sukachev Institute of Forest Siberian Branch of Russian Academy of Sciences Krasnoyarsk Russia
Austrian Polar Research Institute Vienna Austria
Bolin Centre for Climate Research Stockholm University Stockholm Sweden
Central Siberian Botanical Garden Siberian Branch of Russian Academy of Sciences Novosibirsk Russia
Department of Biology Centre for Geobiology University of Bergen Bergen Norway
Department of Bioscience Centre for Geomicrobiology Aarhus Denmark
Department of Ecogenomics and Systems Biology University of Vienna Vienna Austria
Department of Ecosystems Biology University of South Bohemia České Budéjovice Czech Republic
Department of Environmental Science and Analytical Chemistry Stockholm University Stockholm Sweden
Department of Microbiology and Ecosystem Science University of Vienna Vienna Austria
Department of Natural Resources and the Environment University of New Hampshire Durham New Hampshire
Federal Institute for Geosciences and Natural Resources Hannover Germany
Institute of Biostatistics Leibniz Universität Hannover Hannover Germany
Institute of Microbiology Ernst Moritz Arndt University Greifswald Germany
Institute of Soil Science Leibniz Universität Hannover Hannover Germany
Max Planck Institute for Biogeochemistry Jena Germany
Soil Ecology University of Bayreuth Bayreuth Germany
Soil Science and Soil Protection Martin Luther Universität Halle Wittenberg Halle Germany
Thünen Institute of Climate Smart Agriculture Braunschweig Germany
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