In:
Biogeosciences, Copernicus GmbH, Vol. 18, No. 19 ( 2021-10-11), p. 5491-5511
Abstract:
Abstract. Northern latitude peatlands act as important carbon sources and sinks, but
little is known about the greenhouse gas (GHG) budgets of peatlands that
were submerged beneath the North Sea during the last glacial–interglacial
transition. We found that whilst peat formation was diachronous, commencing between
13 680 and 8360 calibrated years before the present, stratigraphic layering
and local vegetation succession were consistent across a large study area.
Large carbon stores were measured. In situ methane (CH4) concentrations
of sediment pore waters were widespread but low at most sites, with the
exception of two locations. Incubation experiments in the laboratory revealed molecular signatures of
methanogenic archaea, with strong increases in rates of activity upon
methylated substrate amendment. Remarkably, methanotrophic activity and the
respective diagnostic molecular signatures could not be detected.
Heterotrophic Bathyarchaeota dominated the archaeal communities, and bacterial
populations were dominated by candidate phylum JS1 bacteria. In the absence of active methanogenic microorganisms, we conclude that these
sediment harbour low concentrations of widespread millennia-old CH4.
The presence of large widespread stores of carbon and in situ methanogenic
microorganisms, in the absence of methanotrophic microorganisms, holds the
potential for microbial CH4 production if catalysed by a change in
environmental conditions.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-18-5491-2021
DOI:
10.5194/bg-18-5491-2021-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2158181-2
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