Effects of climate change on carbon sequestration in a Danish beech forest during 12 years

The CO2 exchange over a beech forest near Soro, Denmark, was measured continuously during 12 years (19962008). Simultaneously a large number of parameters influencing CO2 uptake were measured which makes it possible to relate the CO2 exchange to recent changes in e.g. temperature, CO2 concentration, and nitrogen load. The CO2 exchange was measured by the eddy covariance method which gives a direct measure of the net ecosystem exchange (NEE) at a half hourly basis. Ecosystem respiration (RE) was estimated from nighttime values and gross ecosystem exchange (GEE) was calculated as the sum of RE and NEE.