Implications for Urban Greening and Preliminary Functional Classification: A Review of BVOC Emissions and Tree Carbon Sequestration in China

Urban trees have a vital role in climate mitigation by enhancing air quality, providing thermal comfort, promoting biodiversity, and improving human well-being, thereby aiding in the achievement of Sustainable Development Goals 3, 11, 13, and 15. Nevertheless, in particular environmental circumstances, their release of biogenic volatile organic compounds (BVOCs) may facilitate the generation of ozone (O3) and secondary organic aerosols (SOA), resulting in a context-sensitive compromise. This analysis consolidates data regarding carbon sequestration and BVOC emissions to guide the choice of sustainable urban tree species in China. A literature review encompassing works from 2002 to 31 August 2026 resulted in 132 entries: 127 peer-reviewed papers, four dissertations, and one preprint. Experimental measurements were emphasized, as they constitute the foundation for remote sensing inversions and model simulations; these techniques offer supplementary validation. The gathered information encompassed carbon sequestration, photosynthetic carbon absorption, BVOC emission rates and their composition, measurement foundations, and spatiotemporal dimensions. The data predominantly depicted urban and forest settings in China, constraining comparisons among analogous indicators and measurement parameters. The research revealed variability in carbon sequestration evaluations and suggested that overall BVOC emission rate by itself cannot define atmospheric hazards. Consequently, we suggest a provisional, trade-off-oriented, synergistic, and provisionally low BVOC-emission category categorization that incorporates carbon-related data, compound-specific BVOC traits, and environmental context. This investigative synthesis bolsters evidence-driven urban greening by connecting climate mitigation, air quality, ecosystem services, and human welfare; yet, it does not represent a verified mechanistic framework or conclusive planting guidelines. The reactions noted under particular Chinese meteorological circumstances, pollution metrics, management strategies, and developmental phases necessitate independent verification prior to their use in other areas or commercial forestry. Broader execution requires regional evaluations of ozone and secondary organic aerosol production potential, local nitrogen oxides, meteorological conditions, human-induced emissions, species characteristics, and sustained monitoring.