Exchange of volatile organic compounds between the atmosphere and the soil

Volatile organic compounds (VOCs) play a crucial role in understanding soil ecology and the atmospheric environment. However, the biochemical cycles of VOCs in soil systems and their relationship to atmospheric VOC exchange remain unclear. The soil system serves as a primary site for the generation, emission, and uptake of VOCs, yet these processes lack sufficient understanding.

This review aims to provide a comprehensive overview of the exchange of VOCs between the soil and the atmosphere. We explore the mechanisms governing the generation, emission, and uptake of VOCs in soils, quantitatively summarizing available data on emission and uptake. Additionally, we highlight common and specific VOCs emitted by various soil sources (litter, roots, bare soil, and soil microbes) and examine their interactions.

The composition and emission rates of VOCs display significant variability across different soils, attributed in part to variations in the contributions of different VOC sources within the soils. Litter and roots predominantly release terpenes, benzenoids, and alcohols, while bare soil and microbes emit higher proportions of alkanes, esters, and alcohols. Despite often being overlooked, soils serve as essential sinks for VOCs, and global environmental changes may reshape patterns of soil VOC sources and sinks.