Significance of dark CO2 fixation in arctic soils

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F18%3A43897454" target="_blank" >RIV/60076658:12310/18:43897454 - isvavai.cz</a>

Result on the web

<a href="https://reader.elsevier.com/reader/sd/pii/S0038071717307010?token=97D5E440A8ECC43EAA67A30DD8DAEEC05CCED4807E2037319AD5E1970FDF4415779A0EB53EBDA30050A95EBDB43E578C" target="_blank" >https://reader.elsevier.com/reader/sd/pii/S0038071717307010?token=97D5E440A8ECC43EAA67A30DD8DAEEC05CCED4807E2037319AD5E1970FDF4415779A0EB53EBDA30050A95EBDB43E578C</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.soilbio.2017.12.021" target="_blank" >10.1016/j.soilbio.2017.12.021</a>

Result language

angličtina

Original language name

Significance of dark CO2 fixation in arctic soils

Original language description

The occurrence of dark fixation of CO2 by heterotrophic microorganisms in soil is generally accepted, but its importance for microbial metabolism and soil organic carbon (C) sequestration is unknown, especially under C limiting conditions. To fill this knowledge gap, we measured dark (CO2)-C-13 incorporation into soil organic matter and conducted a C-13-labelling experiment to follow the C-13 incorporation into phospholipid fatty acids as microbial biomass markers across soil profiles of four tundra ecosystems in the northern circumpolar region, where net primary productivity and thus soil C inputs are low. We further determined the abundance of various carboxylase genes and identified their microbial origin with metagenomics. The microbial capacity for heterotrophic CO2 fixation was determined by measuring the abundance of carboxylase genes and the incorporation of C-13 into soil C following the augmentation of bioavailable C sources. We demonstrate that dark CO2 fixation occurred ubiquitously in arctic tundra soils, with increasing importance in deeper soil horizons, presumably due to increasing C limitation with soil depth. Dark CO2 fixation accounted on average for 0.4, 1.0, 1.1, and 16% of net respiration in the organic, cryoturbated organic, mineral and permafrost horizons, respectively. Genes encoding anaplerotic enzymes of heterotrophic microorganisms comprised the majority of identified carboxylase genes. The genetic potential for dark CO2 fixation was spread over a broad taxonomic range. The results suggest important regulatory function of CO2 fixation in C limited conditions. The measurements were corroborated by modeling the long-term impact of dark CO2 fixation on soil organic matter. Our results suggest that increasing relative CO2 fixation rates in deeper soil horizons play an important role for soil internal C cycling and can, at least in part, explain the isotopic enrichment with soil depth.

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

10618 - Ecology

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>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

Soil Biology &amp; Biochemistry

ISSN

0038-0717

e-ISSN

—

Volume of the periodical

119

Issue of the periodical within the volume

APR 2018

Country of publishing house

GB - UNITED KINGDOM

Number of pages

11

Pages from-to

11-21

UT code for WoS article

000428496700002

EID of the result in the Scopus database

2-s2.0-85040237897