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| Titel |
Upland forest soils have a significant contribution to a catchment-scale CH4 balance in a wet year |
| VerfasserIn |
Annalea Lohila, Tuula Aalto, Mika Aurela, Juha Hatakka, Juha-Pekka Tuovinen, Juho Kilkki, Timo Penttilä, Jussi Vuorenmaa, Pekka Hänninen, Raimo Sutinen, Yrjö Viisanen, Tuomas Laurila |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250131459
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| Publikation (Nr.) |
 EGU/EGU2016-11870.pdf |
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| Zusammenfassung |
| Upland forest soils affect the atmospheric methane (CH4) balance, not only through the
soil sink, but also due to episodic high emissions in wet conditions. We measured
methane fluxes in a northern boreal catchment and found that during a wet autumn the
forest soil turned from a CH4 sink into a large source for several months, while
the CH4 emissions from a nearby wetland did not increase. When upscaled to the
whole catchment area with ca. 4/5 of the total area consisting of upland forests
and the rest being wetlands, forests contributed 60% of the annual CH4 emission
from the wetlands. In a normal year, the forest soil consumes 10% of the wetland
emission. In a monthly scale, the autumn emissions from the upland forests were
twice as high as those from wetlands within the same catchment. The period of
unusually high upland soil emission was also captured by the nearby atmospheric
concentration measurement station. Moreover, the monthly atmospheric CH4 anomalies
in autumn were positively correlated with the water level of the lake collecting
waters from the catchment. Since the land cover within our study catchment is
representative of larger regions, our findings imply that upland forests in the boreal zone
constitute an important part in the global CH4 cycle not previously accounted for. |
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