Flowering street trees provide ecological services and health benefits to humans. In this study, three commonly used flowering street trees, Paulownia tomentosa (Thunb.) Steud., Melia azedarach L., and Magnolia grandiflora L., were selected for analysis of floral volatiles during different flowering stages along roadsides in Shanghai, China. Headspace sampling solid-phase microextraction (HS–SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used to identify volatiles from different floral samples. Simultaneously, selected-ion flow-tube mass spectrometry (SIFT–MS) was employed to detect biogenic volatile organic compounds (BVOCs) in roadside air samples. The results indicated that (1) P. tomentosa volatiles consisted predominantly of alcohols and phenolic ethers, M. azedarach volatiles consisted primarily of alcohols and aldehydes, and M. grandiflora volatiles consisted mainly of terpenes. (2) Air samples from P. tomentosa and M. azedarach were dominated by alcohols, whereas air samples from M. grandiflora were dominated by terpenes and aldehydes. The ozone formation potential (OFP) of some VOCs fluctuated throughout the flowering period. (3) Antibacterial and antioxidant volatiles released from the flowers of all species, such as eugenol, have demonstrated health-promoting effects in essential oils. The results of this study provide a foundation for optimizing the selection and planting of flowering street trees in urban roadside areas that will enhance ecological services and public health benefits.
Wang et al. (Sun,) studied this question.