Assessing ozone pollution and climate change impacts on winter wheat: flux modeling vs. dose-response modeling.

Surface ozone is a phytotoxic pollutant that damages photosynthetic systems, reduces gas exchange, retards vegetation growth, and decreases yield. In this study, we developed a new ozone flux module within an agroecosystem model framework to enhance our ability to understand, measure, and predict the impact of surface ozone on agricultural productivity. The new module was calibrated and evaluated against historical observational data from multiple sites. It was then applied to predict winter wheat yield and gross primary productivity (GPP) in response to future ozone changes under different climate scenarios. The new ozone flux model was more sensitive to ozone concentration changes than the ozone dose-response model, demonstrating greater GPP and yield losses at the same ozone pollution level. We also investigated several key environmental factors (temperature, precipitation, carbon dioxide) and their synergistic effects with and without ozone to explore the complexity of ozone pollution impacts under climate change. The simulation results indicate a worsening food crisis, driven by interannual trends in crop losses from ozone pollution under high- and moderate-emission scenarios. A more accurate understanding and qualification of ozone's effects on crop growth and yield is essential for safeguarding food security.