Biogenic volatile organic compounds (BVOCs) are critical trace reactive organic gases in the Earth system, playing vital roles in global carbon cycling, atmospheric chemistry, and climate regulation. BVOCs react rapidly with atmospheric oxidants (e.g., OH, O3, and NO3), driving the formation of secondary organic aerosols (SOA), which modulate radiative forcing and influence regional and global climates. Furthermore, BVOCs interact with tropospheric and stratospheric ozone and alter hydroxyl radical (OH) concentrations, indirectly affecting the lifecycles of greenhouse gases. Global BVOC emissions are estimated to exceed 1000 TgC annually, with forests being the primary source and isoprene and monoterpenes dominating the emissions. Recent advancements in BVOC emission monitoring technologies have significantly improved the resolution and accuracy of emission measurements. Traditional offline sampling and gas chromatography-mass spectrometry (GC-MS) have been complemented by high-temporal-resolution online techniques such as proton-transfer-reaction mass spectrometry (PTR-MS) and time-of-flight mass spectrometry (PTR-ToF-MS). Additionally, multi-scale monitoring tools, including drones, satellite remote sensing, and ground-based flux towers, provide unprecedented capabilities for studying the spatial and temporal dynamics of BVOC emissions. By integrating dynamic chamber methods, eddy covariance techniques, and modeling approaches, researchers are progressively refining BVOC emission inventories, paving the way for deeper insights into the complex feedback mechanisms between BVOCs and climate change.
Environmental factors regulating BVOC emissions have been extensively studied. Light and temperature are key drivers, with light intensity directly influencing photosynthesis and isoprene emissions, while rising temperatures accelerate BVOC biosynthesis and volatilization. Elevated CO2 concentrations may modulate BVOC emissions through photosynthetic regulation and reduced stomatal conductance, although long-term effects vary by plant species and adaptive strategies. Increased ozone (O3) concentrations exert dual effects on BVOCs, inducing stress-related defensive emissions while potentially damaging foliage and suppressing emissions. Aerosol concentrations exhibit critical positive feedback mechanisms with BVOCs—high BVOC emissions promote SOA formation, and SOA, in turn, modifies photosynthesis and BVOC emissions via light scattering effects. Changes in the nitrogen cycle also impact BVOC emissions, with elevated nitrogen inputs altering nutrient allocation and metabolic pathways, thereby enhancing or suppressing BVOC synthesis depending on the compound type.
Under future global change scenarios, climate warming, frequent extreme weather events, and rising CO2 concentrations may significantly alter BVOC emission patterns and their coupling with atmospheric chemistry and climate systems. Advancing observation and modeling approaches to study multi-factor interactions and long-term trends in BVOC emissions is essential for elucidating the cross-sphere coupling mechanisms of BVOCs. Such research will provide critical insights into the interactions between climate change and atmospheric chemistry.
