Can Fertilization OF CO2 Heal the Ozone-Injured Agroecosystems?

The rising concentrations of carbon dioxide (CO2) and ozone (O3) in the atmosphere hold significant implications for various ecosystem services, particularly agroecosystem productivity. This review examines the intricate interplay between the divergent effects of CO2 fertilization and oxidative O3 damage on agroecosystems, with a focus on the pivotal role they play in shaping global food security. A comprehensive analysis of aggregated data from previous studies, employing regression analysis, suggests that CO2 may hold the upper hand and exhibit the potential to mitigate the damage induced by O3. The physiological responses of plants to these atmospheric gases are crucial determinants of their impacts in the coming years. Stomatal conductance (gs) regulates the entry of CO2 and O3 into plant systems, while carboxylation efficiency (Vmax) influences photosynthetic yield (Ps). However, the complex spatial and temporal variations, and the uncertain future projections of O3 concentrations, make it challenging to precisely predict the outcomes of O3–CO2 interactions in agroecosystems. Moreover, the differential responses of various crop functional types add to the complexity, making it even more demanding to assess agroecosystem productivity under future scenarios of atmospheric O3 and CO2 concentrations. To address these uncertainties, urgent efforts are required to quantify the interactive effects of O3 and CO2 across all RCP scenarios. This will provide a clearer understanding of crop responses and agroecosystem productivity in the coming years, ensuring sustainable food security, amidst changing environmental conditions. This review highlights the pressing need for further research to elucidate these critical interactions and their implications for global agriculture.