Pooling of CO2within a small valley in a tropical seasonal rain forest

AbstractCO2concentrations and related environmental factors were measured in an Asian tropical rainforest located in a small valley in Xishuangbanna, SW China, with the aim of investigating the CO2pooling effect and its mechanism of formation. Pooling of CO2was observed during the evening (1600–2200 hours local time); the accumulated CO2subsequently flowed away after dusk. We consider that along-slope drainage flow, soil CO2efflux, and temperature inversion contribute to the development of CO2pooling. A new model is proposed to track the mechanism of the formation and dissipation of CO2pooling (e.g., drainage flow, compensatory mechanisms). Given its influence on the storage term, we suggest that CO2pooling and subsequent disappearance should be taken into account when calculating eddy covariance and other micrometeorological measurements of carbon flux for valley sites.