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| Titel |
Greenhouse gas emissions of drained fen peatlands in Belarus are controlled by water table, land use, and annual weather conditions |
| VerfasserIn |
Andrei Burlo, Merten Minke, Hanna Chuvashova, Jürgen Augustin, Mathias Hoffmann, Ivan Narkevitch |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086941
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| Publikation (Nr.) |
 EGU/EGU2014-887.pdf |
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| Zusammenfassung |
| Drainage of peatlands causes strong emission of the greenhouse gases (GHG) CO2 and N2O,
sometimes combined with a weak CH4 uptake. In Belarus drained peatlands occupy about
1505000 ha or more than 7.2 % of the country area. Joosten (2009) estimates CO2 emission
from degraded peatlands in Belarus as 41.3 Mt yr-1 what equals to 47 % of total
anthropogenic greenhouse gases (GHGs) emission of country in 2011. However, it could not
be checked if these numbers are correct since there are no GHG measurements on these sites
up to now.
Therefore we studied the GHG emissions with the closed chamber approach in four
peatlands situated in central and southern Belarus over a period from August 2010 to August
2012. The measurements comprised eight site types representing different water level
conditions, and ranging from grassland and arable land over abandoned fields and peat cuts to
near-natural sedge fens. Fluxes of CH4 and N2O were determined using the close-chamber
approach every second week in snow free periods and every fourth week during winter time.
The annual emissions were calculated based on linear interpolation. Carbon dioxide
exchange was measured with transparent and opaque chambers every 3-4 weeks
and the annual net ecosystem exchange (NEE) was modeled according to Drösler
(2005).
Most of the drained sites were sources of CO2 in both years. NEE increased with lower
mean annual water table level. The highest NEE value (1263.5 g CO2-C m-1yr-1) was
observed at the driest site of the study; an abandoned fen formerly used for agriculture. In
contrast, a former peat extraction site with moist peat and small Pinus sylvestris tress were
sinks of CO2 with uptake to 389.6 g CO2-C m-1yr-1. The highest N2O emissions were
recorded at a drained agricultural fen with mean annual rates of up to 2347 mg N2O-N m-2
yr-1. Significant fluxes of CH4 (15 gCH4Cm-2 h-1) were observed only at
the near-natural site in the first year of investigation when precipitation and the
mean water level were high. At the drained sites fluxes of CH4 were mainly close
to null and sometimes a weak uptake of CH4 (-0.06 mg CH4-C m-2 h-1) was
observed. In general the results show an increase of global warming potential of site
with decreasing mean annual water level from 5.5 t CO2 equivalents ha-1yr-1 at
near-natural site with annual mean water level -8 cm to 51 t CO2 equivalents ha-1yr-1 at
abandoned fen formerly used for agriculture with mean annual water level near -90
cm.
This study was conducted in the framework of the BMU financed project “Restoring
Peatlands and applying Concepts for Sustainable Management in Belarus – Climate Change
Mitigation with Economic and Biodiversity Benefits”.
Joosten H. The Global Peatland CO2 Picture: peatland status and drainage related
emissions in all countries of the world – 2009. |
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