CO2 Emissions from Semi-Arid Reservoirs and Natural Aquatic Ecosystems

Carbon dioxide (CO2) gross fluxes were measured at the air-water interface of 57 aquatic ecosystems in the western semi-arid region of the USA in April 2003. Fluxes were obtained with a floating chamber connected to an automated NDIR instrument. The results showed a strong similarity between lakes and reservoirs, as is also the case in boreal regions. The values ranged from −1500 to 10800 mg CO2·m−2·d−1 for both natural systems and reservoirs. These values are similar to those observed in boreal regions. Although several limnological parameters can influence the fluxes of CO2, only the pH was significantly related with the CO2 gross fluxes, which decrease with increasing pH.