This dataset was formed from the data collected in the field during 2008 in a pine forest in Tuscany, Italy, aiming at measuring the variability of the CO2 fluxes along one year. The CO2 efflux from soil was determined by an EGM-1 PP Systems portable gas analyser (Hitchin, UK) coupled with an SRC-1 closed air-circulation chamber 1.17 dm³ in volume. Within a 1/3 ha wide area we selected 50 spots to monitor throughout the year, by a randomization procedure.