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| Titel |
Seasonal variations in CH4 emissions and stable isotope signatures from
an ombrotrophic peat bog |
| VerfasserIn |
Mounir Takriti, Sue Ward, Peter Wynn, Rob Rose, Beverly Dodd, Alexander Chadwick, Simon Oakley, Niall McNamara |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250151103
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| Publikation (Nr.) |
 EGU/EGU2017-15649.pdf |
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| Zusammenfassung |
| Natural wetlands are the largest source of CH4 emissions globally. However, despite a wealth
of literature and field measurements, there is still considerable uncertainty about total
emissions, largely due to the high seasonal and inter-annual variability in fluxes. The use of
Stable isotopes provides a powerful technique for investigating CH4 biogeochemistry. In
order to better constrain wetland greenhouse gas emissions we need to improve our
understanding of how emissions and their isotopic signatures respond to seasonal changes in
environmental controls. In peatlands, part of the CH4 produced under anaerobic conditions
may be oxidised by methanotrophic bacteria in the top aerobic layer of the peat. Both
microbial CH4 production and oxidation will be driven by environmental conditions, but may
show independent responses, while their relative magnitude will affect total emissions and
their isotopic signature. In order to improve our understanding of these important
processes in wetland CH4 emissions we set up a 12-month study at an ombrotrophic
peat bog in northern England. Weekly chamber flux measurements were combined
with monthly stable isotope (13C/12C, 2H/1H) measurements, climate, and soil
parameters to investigate how seasonal changes in environmental conditions affect
CH4 fluxes and their isotopic signatures as an indicator of the balance between
CH4 production and oxidation. We show a seasonal pattern in total emissions with
higher fluxes in summer and autumn, and expect to find a concomitant seasonal
pattern in isotope signatures due to changes in the relative activity of methanotrophs. |
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