Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands – responses to climatic and environmental changes

Carter, M. S.; Larsen, K. S.; Emmett, B.; Estiarte, M.; Field, C.; Leith, I. D.; Lund, M.; Meijide, A.; Mills, R. T. E.; Niinemets, Ü.; Peñuelas, J.; Portillo-Estrada, M.; Schmidt, I. K.; Selsted, M. B.; Sheppard, L. J.; Sowerby, A.; Tietema, A.; Beier, C.

In this study, we compare annual fluxes of methane (CH 4), nitrous oxide (N 2O) and soil respiratory carbon dioxide (CO 2) 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 CH 4, whereas the peatlands were CH 4 sources, with fluxes ranging from −519 to +6890 mg CH 4-C m −2 yr −1 across the studied ecosystems. At the peatland sites, annual CH 4 emission increased with mean annual air temperature, while a negative relationship was found between net CH 4 uptake and the soil carbon stock at the shrubland sites. Annual N 2O fluxes were generally small ranging from −14 to 42 mg N 2O-N m −2 yr −1. Highest N 2O emission occurred at the sites that had highest nitrate (NO 3) concentration in the soil water. Furthermore, experimentally increased NO 3 deposition led to increased N 2O efflux, whereas prolonged drought and long-term drainage reduced the N 2O efflux. Soil CO 2 emissions in control plots ranged from 310 to 732 g CO 2-C m −2 yr −1. Drought and long-term drainage generally reduced the soil CO 2 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 CO 2 efflux dominated the response in all treatments (ranging 71–96%), except for NO 3 addition where 89% was due to change in CH 4 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 CO 2 fluxes.

Zitieren

Zitierform:

Carter, M. S. / Larsen, K. S. / Emmett, B. / et al: Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands – responses to climatic and environmental changes. 2012. Copernicus Publications.

Zugriffsstatistik

Gesamt:
Volltextzugriffe:
Metadatenansicht:
12 Monate:
Volltextzugriffe:
Metadatenansicht:

Grafik öffnen

Rechte

Rechteinhaber: M. S. Carter et al.

Nutzung und Vervielfältigung:

Export