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Titel |
Greenhouse gas exchange and global warming potential of a peat bog restoration sequence in NW Germany |
VerfasserIn |
Sascha Beetz, Horst Liebersbach, Heinrich Höper, Matthias Drösler, Stephan Glatzel |
Konferenz |
EGU General Assembly 2011
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 13 (2011) |
Datensatznummer |
250045927
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Zusammenfassung |
About 13,000 km2 (3.6%) of the land area in Germany is covered by peat. Due to multiple
land use patterns and a wide variety of peatland types, the assessment of emission factors for
many peat land use combinations has been difficult and reliable data on the exchange of
carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), between soil and atmosphere
of these areas is particularly scarce. The project investigates the greenhouse gas
exchange of a peat bog restoration sequence over a period of 2 years (July 2007 – June
2009).
The sites were set up at a raised bog, situated in the “Ahlen-Falkenberger Moor”, 50 km
NW of Hamburg (precipitation 926mm/a, annual average temperature 8.5Ë C 1961-1990).
We set up three replicate plots on each agricultural use:
Intensive Grassland (GI, mineral fertilizer, cattle manure and 4-5 cuts/a)
Extensive Grassland (GE, no fertilizer or manure, 1 pruning/a)
Near–Natural peat bog
Based on biweekly CH4 N2O flux and CO2 NEE determinations every 3 – 4 weeks using
closed chamber techniques, we obtained seasonal and annual estimates of GHG
exchange.
Our analysis resulted in an emission rate of 664 ± 169 g CO2-C/(m2*a) in the first (dry)
and 828 ± 140g CO2-C/(m2*a) in the second (wet) year emitted from the intensive used
grassland site. The extensive used site showed a slight CO2-C uptake in the first year (-137 ±
143 g CO2-C/(m2*a)), and a small emission rate of 90 ± 146 g CO2-C/(m2*a) in the second
year. In contrast to these sites, the near-natural area showed a CO2-C-uptake in both years
of -10 ± 66 g CO2-C/(m2*a) and -125 ± 51 g CO2-C/(m2*a). Considering the
N2O and CH4 exchange, this leads to a total GWP of 771 g C – equivalents/a for
GI, -16 g C – equivalent/a for GE and -64 g C – equivalent/a for the Near Natural
site.
The results show that, despite considerable interannual variability, restoration measures
quickly contribute to mitigating large GHG emission rates and approach the carbon
sequestration potential of near natural sites. |
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