Carbon Dioxide Fertilization Effects Offset the Vegetation GPP Losses of Woodland Ecosystems Due to Surface Ozone Damage in China

Air pollution and climate change pose an increasingly serious threat to the sustainable development of terrestrial forest ecosystems. Extensive research in China has focused on single environmental factors, such as ozone, carbon dioxide, and climate change, but the multifactor interactions remain poorly understood. Here, we coupled the interactions of climate change, elevated CO₂ concentration, and increasing O₃ into the BEPS_O₃ model. The gross primary production (GPP) simulated by the BEPS_O₃ is verified at site scale by using the eddy covariance (EC) derived gross primary production data in China. We then investigated the impact of ozone and CO₂ fertilization on woodland ecosystem gross primary production in the context of climate change during 2001–2020 over China. The results of multi-scenario simulations indicate that the gross primary production of woodland ecosystems will increase by 1–5% due to elevated CO₂. However, increased ozone pollution will result in a gross primary production loss of approximately 8–9%. In the historical climate, under the combined effects of CO₂ and O₃, the effect of ozone on gross primary production will be mitigated by CO₂ to 4–7%. In most areas, the effect of ozone on woodland ecosystems is higher than that of CO₂ on vegetation photosynthesis, but CO₂ gradually counteracts the effect of ozone on the ecosystem. Our simulation study provides a reference for assessing the interactive responses to climate change, and advances our understanding of the interactions of global change agents over time. In addition, the comparison of individual and combined models will provide an important basis for national emission reduction strategies as well as O₃ regulation and climate adaptation in different regions. This also provides a data reference for China’s sustainable development policies.