Temperature response of permafrost soil carbon is attenuated by mineral protection

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F18%3A43897766" target="_blank" >RIV/60076658:12310/18:43897766 - isvavai.cz</a>

Result on the web

<a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.14316" target="_blank" >https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.14316</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/gcb.14316" target="_blank" >10.1111/gcb.14316</a>

Result language

angličtina

Original language name

Temperature response of permafrost soil carbon is attenuated by mineral protection

Original language description

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 degrees 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 C-14 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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10511 - Environmental sciences (social aspects to be 5.7)

Project

<a href="/en/project/GA16-18453S" target="_blank" >GA16-18453S: MiCryoFun - Microorganisms in Arctic cryoturbated soils - drivers of organic matter transformations in a changing climate</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Global Change Biology

ISSN

1354-1013

e-ISSN

—

Volume of the periodical

24

Issue of the periodical within the volume

8

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

3401-3415

UT code for WoS article

000437284700013

EID of the result in the Scopus database

2-s2.0-85047829376