Soil Biogenic Volatile Organic Compounds: Sources, Sinks, Emission Controls, and Ecological Functions

Biogenic volatile organic compounds released from soil (SBVOCs) are an important component of the material exchange and information transmission between terrestrial ecosystems and the atmosphere. Soil ecosystems act as both critical sources and frequently overlooked sinks of BVOCs. SBVOC emissions are mainly regulated by the temperature, moisture, and pH of the soil. Climate warming may enhance volatilization and microbial production in the short term. However, its long-term effects depend on drought, vegetation composition, substrate availability, permafrost thaw, and microbial acclimation. SBVOCs also influence microbial activity, nutrient cycling, plant–microbe interactions, plant defence, and below ground trophic interactions, although the strength of evidence differs among these functions. Ecologically, SBVOCs promote carbon cycling, modulate plant-microbe interactions, and influence atmospheric chemistry. This review further synthesizes SBVOC emission and uptake patterns across different climatic zones. Several challenges remain, particularly the scarcity of long-term quantitative measurements and difficulties in distinguishing multiple emission sources. Our understanding of rhizosphere interactions and climate-change feedback is also limited. It is essential to enhance long-term observational studies and optimize models to deepen our understanding of the role of SBVOCs in the global carbon cycle and air quality.