Swiss FACE Experiment
The experiment was carried out to understand the response of grassland ecosystems to elevated atmospheric CO2 partial pressures.
The Swiss FACE experiment demonstrated that CO2-induced changes in the botanical composition, in the dry matter allocation and composition, and in the symbiotic N2 fixation lead to multiple changes in a grassland ecosystem.
Those changes increased nitrogen and carbon input and sequestration into the ecosystem; such an input could act through a feed-back mechanism towards equilibrating the C/N ratio of the whole ecosystem.
However, the driving mechanisms are only poorly understood. Long-term experiments with different management treatments must be conducted to allow a realistic assessment of the long-term response of grassland to elevated pCO2.