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| Titel |
Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands – responses to climatic and environmental changes |
| VerfasserIn |
M. S. Carter, K. S. Larsen, B. Emmett, M. Estiarte, C. Field, I. D. Leith, M. Lund, A. Meijide, R. T. E. Mills, Ü. Niinemets, J. Peñuelas, M. Portillo-Estrada, I. K. Schmidt, M. B. Selsted, L. J. Sheppard, A. Sowerby, A. Tietema, C. Beier |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 10 ; Nr. 9, no. 10 (2012-10-04), S.3739-3755 |
| Datensatznummer |
250007317
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| Publikation (Nr.) |
 copernicus.org/bg-9-3739-2012.pdf |
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| Zusammenfassung |
In this study, we compare annual fluxes of methane (CH4), nitrous oxide
(N2O) and soil respiratory carbon dioxide (CO2) measured at nine
European peatlands (n = 4) and shrublands (n = 5). The sites range from
northern Sweden to Spain, covering a span in mean annual air temperature from
0 to 16 °C, and in annual precipitation from 300 to
1300 mm yr−1. The effects of climate change, including temperature
increase and prolonged drought, were tested at five shrubland sites. At one
peatland site, the long-term (> 30 yr) effect of drainage was assessed,
while increased nitrogen deposition was investigated at three peatland sites.
The shrublands were generally sinks for atmospheric CH4, whereas the
peatlands were CH4 sources, with fluxes ranging from −519 to
+6890 mg CH4-C m−2 yr−1 across the studied ecosystems. At
the peatland sites, annual CH4 emission increased with mean annual air
temperature, while a negative relationship was found between net CH4
uptake and the soil carbon stock at the shrubland sites. Annual N2O
fluxes were generally small ranging from −14 to
42 mg N2O-N m−2 yr−1. Highest N2O emission occurred
at the sites that had highest nitrate (NO3−) concentration in the
soil water. Furthermore, experimentally increased NO3− deposition led
to increased N2O efflux, whereas prolonged drought and long-term
drainage reduced the N2O efflux. Soil CO2 emissions in control
plots ranged from 310 to 732 g CO2-C m−2 yr−1. Drought and
long-term drainage generally reduced the soil CO2 efflux, except at a
hydric shrubland where drought tended to increase soil respiration.
In terms of fractional importance of each greenhouse gas to the total
numerical global warming response, the change in CO2 efflux dominated
the response in all treatments (ranging 71–96%), except for
NO3− addition where 89% was due to change in CH4 emissions.
Thus, in European peatlands and shrublands the effect on global warming
induced by the investigated anthropogenic disturbances will be dominated by
variations in soil CO2 fluxes. |
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