Aerobic soils are an important sink for atmospheric methane, which is the second important greenhouse gas. There is virtually no information on the sink function of boreal ecosystems for methane. In addition, information on quantification and identification of the micro-organisms involved in this proces is rare. During the INTAS project (International association for the promotion of co-operation with scientists from the new independent states of the former Soviet Union) biogeochemical and microbiological research will be carried out, leading to a better understanding of the role of boreal ecosystems in the global methane budget.