Species-explicit inventory of forest biogenic volatile organic emissions across China with MEGAN v3.2

Abstract. Biogenic volatile organic compounds (BVOCs) are important precursors of secondary organic aerosols and tropospheric ozone, yet their emissions are commonly modelled at the plant functional type (PFT) level, which obscures substantial interspecies variability. This limitation is particularly acute for China, where high forest diversity and ambitious afforestation initiatives are expected to reshape national BVOC budgets. Here, we present a species-explicit BVOC emissions inventory for China covering 234 tree species (https://doi.org/10.5281/zenodo.20396128, Liu et al., 2026). The inventory was developed within the Model of Emissions of Gases and Aerosols from Nature (MEGAN) v3.2 modeling framework, with refined inputs comprising species-specific emission factors and high-resolution forest composition data for China. Total forest BVOC emissions were estimated at 10.26 Tg in 2019, with summer emissions accounting for about 50 % of the annual total and a clear decreasing gradient from southern to northern China. Emissions were highly concentrated among a limited number of species: the five largest contributors, Pinus massoniana, Quercus liaotungensis, Phyllostachys edulis, Cunninghamia lanceolata, and Quercus variabilis accounted for 41.7 % of total emissions while occupying only 25.4 % of forest area. At the compound-class level, Quercus liaotungensis dominated isoprene emissions, whereas Pinus massoniana was the leading contributor to monoterpene emissions. Applying this species-explicit framework to two future afforestation scenarios with identical planted areas but contrasting species composition, we found that BVOC emissions may increase by 4.65 Tg yr⁻¹ with the biomass-maximization tree species and by 5.10 Tg yr⁻¹ under the most environmental-suitability species. The dominant compound class and species contributors differed markedly between scenarios, indicating that afforestation-driven BVOC responses depend strongly on species selection. These results demonstrate the importance of incorporating species-specific emission traits BVOC models and suggest that future afforestation strategies could substantially reshape both the magnitude and chemical composition of biogenic emissions, with implications for atmospheric chemistry and air quality.