Ozone pollution and carbon assimilation in vegetation: mechanisms, interactions, and global implications
摘要
Ozone (O3) and carbon dioxide (CO2) critically influence climate change through complex interactions with terrestrial vegetation. Ground-level O3 forms via NOx and VOCs photochemistry, while CO2 primarily comes from fossil fuel combustion. Their atmospheric concentrations interact through physicochemical processes: elevated CO2 levels may accelerate photochemical reaction rates of O3 precursors due to climate warming, while O3, as a potent oxidant, alters atmospheric oxidation capacity and consequently affects the lifetime of other greenhouse gases. Plant stomata serve as the primary interface for gas exchange between terrestrial ecosystems and the atmosphere, playing a critical role in regulating O3 uptake and CO2 assimilation. Plants simultaneously uptake CO2 for photosynthesis and absorb O3 through stomata. Interestingly, rising CO2 concentrations induce partial stomatal closure, thereby reducing O3 uptake. Conversely, elevated O3 concentrations entering stomata trigger oxidative stress responses in plants, leading to decreased stomatal conductance. While this defensive mechanism limits further O3 absorption, it simultaneously restricts CO2 uptake efficiency, ultimately impairing photosynthetic performance and carbon sequestration capacity. This review investigates the ecological effects of O3 and CO2 interactions, focusing on vegetation-mediated gas exchange and its feedback on atmospheric composition. This review examines flux monitoring technologies and modeling approaches, highlighting how O3 pollution influences CO2 assimilation and how plant responses contribute to atmospheric O3 regulation. Key factors such as species traits, growth conditions, and environmental variables are analyzed to evaluate how they modulate these interactions. By synthesizing current understanding of vegetation-regulated O3 and CO2 interactions, this study provides important insights for pollution control and sustainable ecosystem management.