Quantifying the impacts of environmental stress factors on biogenic volatile organic compound emissions in China

Biogenic volatile organic compounds (BVOCs) are key precursors to ozone (O3) and secondary organic aerosol (SOA) formation, influencing both air quality and climate changes. BVOC emissions are highly responsive to environmental stressors such as drought, temperature, and ozone. While significant progress has been made in modeling BVOC emissions, existing studies in China lack a detailed exploration of how different abiotic stressors-particularly in combination-affect emissions and their subsequent impacts on O3 and SOA formation. In this study, we employed the MEGAN 3.2 model to quantify the effects of different stressors (drought, temperature, ozone, COQ, wind, and LAI) on BVOC emissions across China during 2019. Seven scenario simulations were conducted, each isolating individual stressors as well as a combined scenario. Our results show that drought and ozone significantly alter emissions, reducing isoprene and monoterpene output while increasing SOA formation under certain conditions. The largest impacts were observed in Central and Eastern China, where combined stressors led to reductions in BVOC emissions by up to 25 % during summer months. This study provides new insights into how different abiotic stressors interact to influence BVOC emissions and air quality in China. The findings highlight the need for integrated stressor assessments in emission models to better predict O3 and SOA concentrations under future climate scenarios. These results contribute to advancing air quality management strategies, particularly in regions facing increasing environmental stress due to climate change.