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Pàgina inicial > Articles > Articles publicats > Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands - responses to climatic and environmental changes |
Data: | 2012 |
Resum: | 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 N₂0 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. |
Ajuts: | Ministerio de Ciencia e Innovación CSD2008-00040 Ministerio de Ciencia e Innovación CGL2010-17172/BOS Ministerio de Ciencia e Innovación CGL2006-04025/BOS Agència de Gestió d'Ajuts Universitaris i de Recerca 2009/SGR-1511 |
Drets: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. |
Llengua: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Publicat a: | Biogeosciences, Vol. 9 (2012) , p. 3739-3755, ISSN 1726-4189 |
17 p, 1.7 MB |