CO2 flux in alpine wetland ecosystem on the Qinghai-Tibetan Plateau, China

Using the CO2 flux data measured by the eddy covariance method in the northeast of Qinghai-Tibetan Plateau in 2005, we analyzed the carbon flux dynamics in relation to meteorological and biotic factors. The results showed that the alpine wetland ecosystem was the carbon source, and it emitted 316.02 gCO2 · m−2 to atmosphere in 2005 with 230.16 gCO2 · m−2 absorbed in the growing season from May to September and 546.18 gCO2 · m−2 released in the non-growing season from January to April and from October to December. The maximum of the averaged daily CO2 uptake rates and release rates was (0.45 ± 0.0012) mgCO2 · m−2 · s−1 (Mean ± SE) in July and (0.22 ± 0.0090) mgCO2 · m−2 · s−1 in August, respectively. The averaged diurnal variation showed a single-peaked pattern in the growing season, but exhibited very small fluctuation in the non-growing season. Net ecosystem exchange (NEE) and gross primary production (GPP) were all correlated with some meteorological factors, and they showed a negatively linear correlation with aboveground biomass, while a positive correlation existed between the ecosystem respiration (Res) and those factors.