AUTHOR=Zeng Jianqiang , Song Wei , Zhang Yanli , Mu Zhaobin , Pang Weihua , Zhang Huina , Wang Xinming 

TITLE=Emissions of isoprenoids from dominant tree species in subtropical China

JOURNAL=Frontiers in Forests and Global Change

VOLUME=Volume 5 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/forests-and-global-change/articles/10.3389/ffgc.2022.1089676

DOI=10.3389/ffgc.2022.1089676

ISSN=2624-893X

ABSTRACT=Emission factors (Es) are among major sources of uncertainties in regional or global emission estimates of biogenic volatile organic compounds (BVOCs). Tropical vegetation contributes approximately 70% of the global BVOC emissions, yet in-situ measurements of BVOC emissions from tropical tree species, especially naturally grown mature trees, are quite limited. In this study, BVOC emissions from twenty mature trees (15 evergreen broad-leaved and 5 evergreen needle-leaved) were measured using dynamic chambers, and the emitted BVOCs were collected using sorbent tubes and speciated with a thermal desorption-gas chromatography/mass spectrometry system (TD-GC/MS). Twenty BVOC compounds including isoprene, 14 monoterpene (MT) species and 9 sesquiterpene (SQT) species were quantified for calculating their Es. The results showed that Eucalyptus urophylla had the largest Es of isoprene (26.47±3.70 μg g-1 h-1) among all the measured trees, followed by Ficus hispida (20.74±1.78 μg g-1 h-1), Syzygium hainanense (20.49±1.36 μg g-1 h-1), Casuarina equisetifolia (18.70±2.91 μg g-1 h-1) and Mangifera indica (11.71±7.04 μg g-1 h-1). α-Pinene, β-pinene and limonene were the most abundant MTs, of which the largest Es were measured for Magnolia denudata (8.33±2.05 μg g-1 h-1), Castanopsis hystrix (5.29±3.24 μg g-1 h-1) and Magnolia denudata (3.11±1.07 μg g-1 h-1), respectively. The Es of SQT for the measured trees were lower than 0.50 μg g-1 h-1 except for Magnolia denudata (1.10±0.41 μg g-1 h-1). β-Caryophyllene was the most common SQT with Magnolia denudata having the highest β-Caryophyllene Es of 0.09±0.03 μg g-1h-1. The localized Es measured for dominant tree species could be used to update BVOC emission factors for typical vegetation types and help improve BVOC emission estimates in typical/subtropical regions and narrow their uncertainties.