Characteristics and Chemical Reactivity of Biogenic Volatile Organic Compounds from Dominant Forest Species in the Jing-Jin-Ji Area, China
Background: Biogenic volatile organic compounds (BVOCs) play an essential role in tropospheric atmospheric chemical reactions. There are few studies on BVOCs emission of dominant tree species in the Jing-Jin-Ji area. Based on the field survey, forest resources data and the measured standard emission factors, this paper used Guenther model in 1993 (G93) to estimate the emissions of BVOCs from dominant forest species (Platycladus orientalis , Quercus variabilis, Betula platyphylla, Populus
... lla, Populus tomentosa, Pinus tabuliformis, Robinia pseudoacacia, Ulmus pumila, Salix babylonica, Larix gmelinii) in the Jing-Jin-Ji area in 2017, analyzed their spatiotemporal emission characteristics and evaluated their amospheric chemical reactivity. Results: Results showed that the total annual BVOCs emissions were estimated to be 70.8 Gg C·a-1, consisting of 40.5% (28.7 Gg C·a-1) isoprene, 36.0% (25.5 Gg C·a-1) monoterpenes, and 23.4% (16.6 Gg C·a-1) other VOCs. The emissions of Platycladus orientalis, Quercus variabilis, Populus tomentosa and Pinus tabulaeformis contributed 56.1%, 41.2%, 36.0% and 31.1%, respectively. In summer and winter, BVOCs emissions from the Jing-Jin-Ji area accounted for 61.9% and 1.8% of the annual total. Emissions from Chengde contributed to 28.8%, followed by Beijing, accounting for 24.9%, which was mainly distributed in the Taihang Mountains and the Yanshan Mountains. Robinia pseudoacacia, Populus tomentosa, Quercus variabilis, and Pinus tabulaeformis contributed higher BVOCs reaction activity. Conclusions: Emissions peaked in summer (June, July, and August) and bottomed out in winter (December, January, and February). Chengde contributed the most, followed by Beijing. Platycladus orientalis, Quercus variabilis, Populus tomentosa, Pinus tabulaeformis and Robinia pseudoacacia are the primary BVOCs emission and atmospheric reactivity contributors, the planting rates of these species with significant emissions or atmospheric reactivity of BVOCs should be considered for reduction.