[Text] / B. . Wild [et al.] // Soil Biol. Biochem. - 2014. -
Vol. 75. - P143-151,
DOI 10.1016/j.soilbio.2014.04.014. - Cited References: 47. - This study was funded by the Austrian Science Fund (FWF) as part of the International Program CryoCARB (Long-term Carbon Storage in Cryoturbated Arctic Soils; FWF - I370-B17).
. - ISSN 0038-0717
РУБ Soil Science
Аннотация: Rising temperatures in the Arctic can affect soil organic matter (SOM) decomposition directly and indirectly, by increasing plant primary production and thus the allocation of plant-derived organic compounds into the soil. Such compounds, for example root exudates or decaying fine roots, are easily available for microorganisms, and can alter the decomposition of older SUM ("priming effect"). We here report on a SUM priming experiment in the active layer of a permafrost soil from the central Siberian Arctic, comparing responses of organic topsoil, mineral subsoil, and cryoturbated subsoil material (i.e., poorly decomposed topsoil material subducted into the subsoil by freeze-thaw processes) to additions of C-13-labeled glucose, cellulose, a mixture of amino acids, and protein (added at levels corresponding to approximately 1% of soil organic carbon). SUM decomposition in the topsoil was barely affected by higher availability of organic compounds, whereas SUM decomposition in both subsoil horizons responded strongly. In the mineral subsoil, SUM decomposition increased by a factor of two to three after any substrate addition (glucose, cellulose, amino acids, protein), suggesting that the microbial decomposer community was limited in energy to break down more complex components of SOM. In the cryoturbated horizon, SUM decomposition increased by a factor of two after addition of amino acids or protein, but was not significantly affected by glucose or cellulose, indicating nitrogen rather than energy limitation. Since the stimulation of SUM decomposition in cryoturbated material was not connected to microbial growth or to a change in microbial community composition, the additional nitrogen was likely invested in the production of extracellular enzymes required for SUM decomposition. Our findings provide a first mechanistic understanding of priming in permafrost soils and suggest that an increase in the availability of organic carbon or nitrogen, e.g., by increased plant productivity, can change the decomposition of SUM stored in deeper layers of permafrost soils, with possible repercussions on the global climate. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).
WOS Держатели документа: [Wild, Birgit
Schnecker, Joerg
Watzka, Margarete
Richter, Andreas] Univ Vienna, Dept Microbiol & Ecosyst Sci, Div Terr Ecosyst Res, Vienna, Austria
[Wild, Birgit
Schnecker, Joerg
Alves, Ricardo J. Eloy
Gittel, Antje
Urich, Tim
Richter, Andreas] Austrian Polar Res Inst, Vienna, Austria
[Alves, Ricardo J. Eloy
Urich, Tim] Univ Vienna, Dept Ecogen & Syst Biol, Div Archaea Biol & Ecogen, Vienna, Austria
[Barsukov, Pavel
Shibistova, Olga] Russian Acad Sci, Siberian Branch, Inst Soil Sci & Agrochem, Novosibirsk, Russia
[Barta, Jiri
Capek, Petr
Santruckova, Hana] Univ South Bohemia, Dept Ecosyst Biol, Ceske Budejovice, Czech Republic
[Gentsch, Norman
Guggenberger, Georg
Mikutta, Robert
Shibistova, Olga] Leibniz Univ Hannover, Inst Soil Sci, D-30167 Hannover, Germany
[Gittel, Antje] Univ Bergen, Ctr Geobiol, Dept Biol, Bergen, Norway
[Lashchinskiy, Nikolay] Russian Acad Sci, Siberian Branch, Cent Siberian Bot Garden, Novosibirsk, Russia
[Shibistova, Olga
Zrazhevskaya, Galina] Russian Acad Sci, Siberian Branch, VN Sukachev Inst Forest, Krasnoyarsk, Russia
ИЛ СО РАН
Доп.точки доступа: Wild, B...; Schnecker, J...; Alves, RJE; Barsukov, P...; Barta, J...; Capek, P...; Gentsch, N...; Gittel, A...; Guggenberger, G...; Lashchinskiy, N...; Mikutta, R...; Rusalimova, O...; Santruckova, H...; Shibistova, O...; Urich, T...; Watzka, M...; Zrazhevskaya, G...; Richter, A...; Austrian Science Fund (FWF) as part of the International Program CryoCARB [FWF - I370-B17]
