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| Titel |
CH4 production in the deep soil as a source of stem CH4 emission
in \textit{Fagus sylvatica}? |
| VerfasserIn |
Martin Maier, Katerina Machacova, Otmar Urban, Friederike Lang |
| 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 |
250154367
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| Publikation (Nr.) |
 EGU/EGU2017-19451.pdf |
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| Zusammenfassung |
| Predicting greenhouse gas (GHG) fluxes on a global scale requires understanding fluxes on
the local scale. Understanding GHG processes in soil-plant-atmosphere systems is
essential to understand and mitigate GHG fluxes on the local scale. Forests are
known to act as carbon sink. Yet, trees at waterlogged sites are known to emit large
amounts of CH4, what can offset the positive GHG balance due the CO2 that is
sequestered as wood. Generally, upland trees like European beech (Fagus sylvatica
L.) are assumed not to emit CH4, and the upland forest soils are regarded as CH4
sinks.
Soil-atmosphere fluxes and stem-atmosphere fluxes of CH4 were studied together with
soil gas profiles at two upland beech forest sites in Germany and Czech Republic. Soil
was a net CH4 sink at both sites. While most trees showed no or low emissions,
one beech tree had exorbitant CH4 emissions that were higher than the CH4 sink
capacity of the soil. A soil survey showed strong redoximorphic color patterns
in the soil adjacent to this tree. Although the soil around the tree was taking up
CH4, the soil gas profiles around this tree showed CH4 production at a soil depth
>0.3 m.
We interpret the coincidence of the production of CH4 in the deep soil below the beech
with the large stem emissions as strong hint that there is a transport link between the soil and
stem. We think that the root system represents a preferential transport system for CH4 despite
the fact that beech roots usually do not have a special gas transport tissue. The observed CH4
stem emissions represent an important CH4 flux in this ecosystem, and, thus, should be
considered in future research.
Acknowledgement
This research was supported by the Czech Academy of Sciences and the German
Academic Exchange Service within the project "Methane (CH4) and nitrous oxide (N2O)
emissions from Fagus sylvatica trees" (DAAD-15-03), the Czech Science Foundation
(17-18112Y), National Programme for Sustainability I (LO1415) and project DFG (MA
5826/2-1). We would like to thank Marek Jakubik, Sinikka Paulus, Ellen Halaburt and Sally
Haddad for technical support. |
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