[Simulated Ozone Damage on Gross Primary Productivity (GPP) in a Winter Wheat Field]

An eddy-covariance system combined with a semi-mechanistic model was used to analyze variations in gross primary productivity (GPP) and to simulate the impact of ozone (O₃) on GPP under different levels O₃ concentrations over a winter wheat field in Nanjing. The results showed that GPP was higher during the middle of the growth period and low during the early and late growth periods, reaching a maximum of 40 μmol·(m²·s)^-1. Using high and low ozone sensitivity settings,O₃-damage in 150, 100, 50 nL·L^-1 and control treatment (CK) reduced GPP by -72%, -36%, -6%, and -10%, and by -13%, -6%, -1%, and -2%, respectively. These results provide a scientific basis for formulating defense strategies for O₃ damage to crops.