Details
| Original language | English |
|---|---|
| Pages (from-to) | 2040-2056 |
| Number of pages | 17 |
| Journal | Global change biology |
| Volume | 14 |
| Issue number | 9 |
| Publication status | Published - 6 Aug 2008 |
| Externally published | Yes |
Abstract
Terrestrial ecosystems in northern high latitudes exchange large amounts of methane (CH4) with the atmosphere. Climate warming could have a great impact on CH4 exchange, in particular in regions where degradation of permafrost is induced. In order to improve the understanding of the present and future methane dynamics in permafrost regions, we studied CH4 fluxes of typical landscape structures in a small catchment in the forest tundra ecotone in northern Siberia. Gas fluxes were measured using a closed-chamber technique from August to November 2003 and from August 2006 to July 2007 on tree-covered mineral soils with and without permafrost, on a frozen bog plateau, and on a thermokarst pond. For areal integration of the CH4 fluxes, we combined field observations and classification of functional landscape structures based on a high-resolution Quickbird satellite image. All mineral soils were net sinks of atmospheric CH4. The magnitude of annual CH4 uptake was higher for soils without permafrost (1.19 kg CH4ha-1 yr-1) than for soils with permafrost (0.37 kg CH4 ha-1yr-1). In well-drained soils, significant CH4 uptake occurred even after the onset of ground frost. Bog plateaux, which stored large amounts of frozen organic carbon, were also a net sink of atmospheric CH4 (0.38 kg CH4 ha-1yr-1). Thermokarst ponds, which developed from permafrost collapse in bog plateaux, were hot spots of CH4 emission (approximately 200 kg CH4 ha-1yr-1). Despite the low area coverage of thermokarst ponds (only 2.1% of the total catchment area), emissions from these sites resulted in a mean catchment CH4 emission of 3.8 kg CH4ha-1yr-1. Export of dissolved CH4 with stream water was insignificant. The results suggest that mineral soils and bog plateaux in this region will respond differently to increasing temperatures and associated permafrost degradation. Net uptake of atmospheric CH4 in mineral soils is expected to gradually increase with increasing active layer depth and soil drainage. Changes in bog plateaux will probably be much more rapid and drastic. Permafrost collapse in frozen bog plateaux would result in high CH4 emissions that act as positive feedback to climate warming.
Keywords
- Active layer, Bog, Catchment, Dissolved methane, Forest tundra, Methane emission, Methaneup take, Permafrost, Thawponds, Thermokarst
ASJC Scopus subject areas
- Environmental Science(all)
- Global and Planetary Change
- Environmental Science(all)
- Environmental Chemistry
- Environmental Science(all)
- Ecology
- Environmental Science(all)
- General Environmental Science
Sustainable Development Goals
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In: Global change biology, Vol. 14, No. 9, 06.08.2008, p. 2040-2056.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Landscape controls of CH4 fluxes in a catchment of the forest tundra ecotone in northern Siberia
AU - Flessa, Heiner
AU - Rodionov, Andrej
AU - Guggenberger, Georg
AU - Fuchs, Hans
AU - Magdon, Paul
AU - Shibistova, Olga
AU - Zrazhevskaya, Galina
AU - Mikheyeva, Natalia
AU - Kasansky, Olega
AU - Blodau, Christian
PY - 2008/8/6
Y1 - 2008/8/6
N2 - Terrestrial ecosystems in northern high latitudes exchange large amounts of methane (CH4) with the atmosphere. Climate warming could have a great impact on CH4 exchange, in particular in regions where degradation of permafrost is induced. In order to improve the understanding of the present and future methane dynamics in permafrost regions, we studied CH4 fluxes of typical landscape structures in a small catchment in the forest tundra ecotone in northern Siberia. Gas fluxes were measured using a closed-chamber technique from August to November 2003 and from August 2006 to July 2007 on tree-covered mineral soils with and without permafrost, on a frozen bog plateau, and on a thermokarst pond. For areal integration of the CH4 fluxes, we combined field observations and classification of functional landscape structures based on a high-resolution Quickbird satellite image. All mineral soils were net sinks of atmospheric CH4. The magnitude of annual CH4 uptake was higher for soils without permafrost (1.19 kg CH4ha-1 yr-1) than for soils with permafrost (0.37 kg CH4 ha-1yr-1). In well-drained soils, significant CH4 uptake occurred even after the onset of ground frost. Bog plateaux, which stored large amounts of frozen organic carbon, were also a net sink of atmospheric CH4 (0.38 kg CH4 ha-1yr-1). Thermokarst ponds, which developed from permafrost collapse in bog plateaux, were hot spots of CH4 emission (approximately 200 kg CH4 ha-1yr-1). Despite the low area coverage of thermokarst ponds (only 2.1% of the total catchment area), emissions from these sites resulted in a mean catchment CH4 emission of 3.8 kg CH4ha-1yr-1. Export of dissolved CH4 with stream water was insignificant. The results suggest that mineral soils and bog plateaux in this region will respond differently to increasing temperatures and associated permafrost degradation. Net uptake of atmospheric CH4 in mineral soils is expected to gradually increase with increasing active layer depth and soil drainage. Changes in bog plateaux will probably be much more rapid and drastic. Permafrost collapse in frozen bog plateaux would result in high CH4 emissions that act as positive feedback to climate warming.
AB - Terrestrial ecosystems in northern high latitudes exchange large amounts of methane (CH4) with the atmosphere. Climate warming could have a great impact on CH4 exchange, in particular in regions where degradation of permafrost is induced. In order to improve the understanding of the present and future methane dynamics in permafrost regions, we studied CH4 fluxes of typical landscape structures in a small catchment in the forest tundra ecotone in northern Siberia. Gas fluxes were measured using a closed-chamber technique from August to November 2003 and from August 2006 to July 2007 on tree-covered mineral soils with and without permafrost, on a frozen bog plateau, and on a thermokarst pond. For areal integration of the CH4 fluxes, we combined field observations and classification of functional landscape structures based on a high-resolution Quickbird satellite image. All mineral soils were net sinks of atmospheric CH4. The magnitude of annual CH4 uptake was higher for soils without permafrost (1.19 kg CH4ha-1 yr-1) than for soils with permafrost (0.37 kg CH4 ha-1yr-1). In well-drained soils, significant CH4 uptake occurred even after the onset of ground frost. Bog plateaux, which stored large amounts of frozen organic carbon, were also a net sink of atmospheric CH4 (0.38 kg CH4 ha-1yr-1). Thermokarst ponds, which developed from permafrost collapse in bog plateaux, were hot spots of CH4 emission (approximately 200 kg CH4 ha-1yr-1). Despite the low area coverage of thermokarst ponds (only 2.1% of the total catchment area), emissions from these sites resulted in a mean catchment CH4 emission of 3.8 kg CH4ha-1yr-1. Export of dissolved CH4 with stream water was insignificant. The results suggest that mineral soils and bog plateaux in this region will respond differently to increasing temperatures and associated permafrost degradation. Net uptake of atmospheric CH4 in mineral soils is expected to gradually increase with increasing active layer depth and soil drainage. Changes in bog plateaux will probably be much more rapid and drastic. Permafrost collapse in frozen bog plateaux would result in high CH4 emissions that act as positive feedback to climate warming.
KW - Active layer
KW - Bog
KW - Catchment
KW - Dissolved methane
KW - Forest tundra
KW - Methane emission
KW - Methaneup take
KW - Permafrost
KW - Thawponds
KW - Thermokarst
UR - http://www.scopus.com/inward/record.url?scp=48849095373&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2486.2008.01633.x
DO - 10.1111/j.1365-2486.2008.01633.x
M3 - Article
AN - SCOPUS:48849095373
VL - 14
SP - 2040
EP - 2056
JO - Global change biology
JF - Global change biology
SN - 1354-1013
IS - 9
ER -