Improved BVOC estimation accuracy by integrating high-resolution land cover and species-specific emission factor in a...

Biogenic volatile organic compounds (BVOCs), key precursors of near-surface ozone (O₃), remain highly uncertain because coarse-resolution land cover data and plant functional type (PFT)-based emission factors (EFs) cannot capture fragmented vegetation and interspecific variability. Here, we developed a 10 m species-specific BVOC emission framework for Xiamen, China, by integrating satellite data with ground-based plant surveys. A localized BVOC EF database covering 115 tree species was established using field measurements of 14 dominant species and literature data. High-resolution mapping better resolved fragmented urban vegetation, increasing urban contributions from 1.71% at 500 m to 5.58% at 10 m. The species-specific framework estimated higher annual BVOC emissions (35.03 Gg) than the 500 m (23.96 Gg) and 10 m (31.29 Gg) PFT-based approaches, while correcting the underestimation of monoterpene emissions in pine-dominated forests caused by uniform PFT-based EFs. Monte Carlo simulations showed markedly reduced uncertainty, with the coefficient of variation decreasing to 1.69. O₃ formation potential were concentrated in mountainous forests, where Pinus massoniana accounted for 28.26%-34.59% of total emissions. This study highlights the importance of integrating high-resolution and species-level data to improve BVOC estimates and support targeted O₃ mitigation strategies.