EFFECTS OF AFFORESTATION ON THE CO_2 BALANCE OF AN AGRICULTURAL PEAT SOIL

摘要

The year-round net ecosystem CO_2 exchange (NEE) was measured with the eddy covariance method above an afforested peat field (35-years old Scots pine forest) in western Finland. The seasonal variation in the flux rates was marked, the forest acting as a CO_2 sink during the 5-month period from the beginning of May until the end of September, and releasing carbon dioxide during the dormant period from October to April. When calculated over the yearly course, the carbon dioxide balance of the afforested peat field was 50 g m~(-2) a~(-1), indicating a small carbon loss from the ecosystem to the atmosphere. Hence, it seems obvious that the relatively high carbon losses from the cultivated peat soils may be reduced by means of afforestation.