Unveiling sesquiterpene emissions in dominant trees of a Brazilian Atlantic Forest remnant

Despite the significance of the Atlantic Forest, little is known about the biogenic volatile organic compound (BVOC) emissions from its tree species. This study aimed to characterize sesquiterpene (SQT) emissions from ten dominant species in a forest remnant near São Paulo, Brazil, using a dynamic enclosure system and gas chromatography–mass spectrometry (GC-MS). A total of 24 SQTs were annotated, including seven oxygenated sesquiterpenes (OSQTs). Emissions ranged from undetectable in Luehea divaricata to 277.54 ng gDM−1 h−1 in Alchornea sidifolia. Hierarchical clustering grouped species into four clusters based on emission intensity and chemical diversity: (1) high emission with low chemical diversity (A. sidifolia), (2) moderate-to-high emission with high diversity (Machaerium brasiliense and Allophylus edulis), (3) moderate emission with low (Guarea macrophylla) to moderate diversity (Machaerium nyctitans, Lithraea molleoides, and Casearia sylvestris), and (4) low emissions and low (Pittosporum undulatum) to moderate diversity (Nectandra barbellata), or undetectable emissions (Luehea divaricata). Most species predominantly emitted α-copaene, β-caryophyllene, or α-cubebene, each linked to defensive/ecological functions like herbivore deterrence and antimicrobial activity. Species with high β-caryophyllene emissions (A. edulis, L. molleoides) or OSQT diversity (A. sidifolia, M. brasiliense, M. nyctitans) emerged as promising candidates for bioprospecting. Conversely, from a SQT-emission perspective, low-emitting species (N. barbellata, P. undulatum, and L. divaricata) represent suitable potential candidates for urban greening due to their limited contribution to secondary pollutant formation. These findings provide a foundation for future BVOC research in the Atlantic Forest and support the strategic selection and application of species based on their SQT emission profiles.