Effects of simulated nitrogen deposition on BVOCs emission dynamics and O3 and SOA production potentials in seedlings of three Ficus species

Nitrogen deposition affects the emission of biogenic volatile organic compounds (BVOCs) and thus their formation of ozone (O₃) and secondary organic aerosols (SOA). The present study employed four nitrogen concentrations (6, 10, 15, and 30 kg ha⁻¹ yr⁻¹) and two nitrogen application methods (foliar surface and root application) to investigate the short-term effects of nitrogen deposition on BVOC emissions in seedlings of Ficus virens, Ficus concinna and Ficus elastica through controlled indoor pot experiments. The results demonstrated a positive correlation between the nitrogen concentration and the emission rate of BVOCs, with leaf nitrogen application exhibiting a significantly greater impact than root nitrogen application. The net photosynthetic rate and stomatal conductance emerged as pivotal factors influencing the emission of BVOCs. The maximum incremental reactivity (MIR) and fractional aerosol coefficient (FAC) methods were employed to assess the contribution of BVOCs to O₃ formation and SOA production. Our findings indicate that isoprene emitted by seedlings from the three plant species emerged as the predominant driver for O₃ formation, while monoterpenes and sesquiterpenes played a pivotal role in SOA production.