Abstract: Two open-top chambers (OTCs) with height 0.4 m (OTC-1) and 0.8 m (OTC-2) were used to simulate the global warming and to study the effects of elevated temperature on the CO₂ flux during growth season in an alpine meadow ecosystem in Qinghai-Tibetan Plateau. The OTC-1 and OTC-2 had an increased mean annual temperature 1.25℃ and 3.68℃, respectively, compared with the control. In the control, OTC-1 and OTC-2, the CO₂ fluxes all showed an evident seasonal variation, and peaked at vigorous growth stage (from July to August), being 2.31, 2.35, and 6.38 μmol·m^-2·s^-1, respectively. At different growth stages, the CO₂ fluxes all showed an increasing trend with the increment of temperature, indicating that global warming could cause the increase of CO₂ flux in alpine meadow. The CO₂ fluxes in the control, OTC-1 and OTC-2 all had significant correlations with air temperature and the soil temperature and moisture at the depth of 5 cm. The correlations between the CO₂ emission fluxes and the air temperature and soil temperature were exponential, and those between the CO₂ emission fluxes and soil moisture were quadric multinomial.

Key words: Bashang region, Ecological footprint, Ecological carrying capacity