Unveiling Sesquiterpene Emissions in Dominant Trees of a Brazilian Atlantic Forest Remnant

Despite the ecological richness and biodiversity of the Atlantic Forest, research on biogenic volatile organic compound (BVOC) emissions from its tree species remains limited. This study characterizes sesquiterpene (SQT) emissions from ten dominant tree species in an Atlantic Forest remnant near São Paulo, Brazil. Emissions and chemical profiles varied significantly, with total SQT emissions ranging from undetectable levels in Luehea divaricata to 295.14 ng gdw⁻¹ h⁻¹ in Alchornea sidifolia. Hierarchical clustering revealed four distinct groups: (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 emission and diversity (Nectandra barbellata, Pittosporum undulatum, and L. divaricata). A total of 26 distinct SQTs were identified, including nine oxygenated sesquiterpenes (OSQTs). Most species predominantly emitted α-copaene, β-caryophyllene, or α-cubebene, compounds that may play important defensive and ecological roles, such as antimicrobial activity and herbivore deterrence. Species with high β-caryophyllene emissions, particularly Allophylus edulis (48.15 ng gdw⁻¹ h⁻¹) and Lithraea molleoides (32.54 ng gdw⁻¹ h⁻¹), or those with high OSQT diversity, such as A. sidifolia (six OSQTs) and M. nyctitans (seven OSQTs), show potential for bioprospecting applications. In contrast, species with low total SQT emissions, such as N. barbellata (6.75 ng gdw⁻¹ h⁻¹), P. undulatum (6.18 ng gdw⁻¹ h⁻¹), and L. divaricata (no detectable emissions), may be better suited for urban greening efforts from a SQT-emission perspective.