Comparison of biogenic volatile organic compounds emissions from representative urban tree species in South Korea and evaluation of standard emission rate models

Abstract

Although trees generally help alleviate global warming, they generate biogenic volatile organic compounds (BVOCs) that may contribute to air pollution and exacerbate climate change. To estimate BVOCs emission rates, several models have been widely used to calculate the standard emission rate (ERs) that takes temperature and light intensity into account. In this study, the effects of temperature and light intensity on the isoprene and monoterpene emissions from various tree species were investigated. Four broad-leaved trees (Platanus occidentalis, Quercus mongolica, Zelkova serrata, and Acer palmatum) and three coniferous trees (Pinus densiflora, Metasequoia glyptostroboides, and Pinus koraiensis) were investigated in August 2022 for the comparison by the species. Emissions from Pinus densiflora were also measured in May for comparison with different climate conditions. Platanus occidentalis revealed the highest emission of isoprene, followed by Quercus mongolica, Zelkova serrata, and Acer palmatum. It was found that the isoprene emissions from Zelkova serrata and Quercus mongolica had a stronger correlation with light intensity than those from Platanus occidentalis. In contrast, the isoprene emissions from Platanus occidentalis exhibited the strongest correlation with temperature compared to other trees concerned. The monoterpene emission from Metasequoia glyptostroboides showed the highest correlation with light intensity (r2 = 0.662). Among the monoterpenes, α-pinene was the most affected by light intensity. Pinus densiflora was affected more by light intensity in May. The ERs estimation using the G93 model confirmed this pattern. Therefore, this study suggests that both light and temperature be taken into account in order to obtain more reliable ERs data of monoterpenes.