Upland soils are important sinks for atmospheric methane ( CH 4 ), a process essentially driven by methanotrophic bacteria. Soil CH 4 uptake often depends on land use, with afforestation generally increasing the soil CH 4 sink. However, the mechanisms driving these changes are not well understood to date. We measured soil CH 4 and N 2 O fluxes along an afforestation chronosequence with Norway spruce (Picea abies L.) establishe...