Impact of the heatwave in 2003 on the summer CH₄ budget of a spruce forest with large variation in soil drainage: A four‐year comparison (2001–2004)

Well‐aerated soils are sinks for atmospheric methane (CH 4 ) whereas hydromorphic soils act as sources. Both CH 4 oxidation and production are highly sensitive to variation in soil moisture. Significant changes of net CH 4 fluxes from soils can therefore be expected to accompany redistribution of precipitation in the course of climate change where more extreme events are predicted for the future. The extreme summer drought in 2003 offered the opportunity to study the impact of such events on methane fluxes under field conditions. The objective was to evaluate the impact of the summer drought in 2003 on net methane budget of a spruce‐forest ecosystem. We studied net CH 4 flux (bi‐)weekly during the summers of 2000–2004 using a closed‐chamber technique on six different soil types ranging from well‐aerated Cambisols, to poorly drained Gleysols and a wet Histosol in a cool‐humid spruce forest.