气候变化领域集成服务门户(CCPortal): Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5-C20) emissions of downy birches

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DOI	10.5194/acp-21-8045-2021
	Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5-C20) emissions of downy birches
	Hellén H.; Praplan A.P.; Tykkä T.; Helin A.; Schallhart S.; Schiestl-Aalto P.P.; Bäck J.; Hakola H.
发表日期	2021
ISSN	1680-7316
起始页码	8045
结束页码	8066
卷号	21 期号:10
英文摘要	Biogenic volatile organic compounds (BVOCs) emitted by the forests are known to have strong impacts in the atmosphere. However, lots of missing reactivity is found, especially in the forest air. Therefore better characterization of sources and identification/quantification of unknown reactive compounds is needed. While isoprene and monoterpene (MT) emissions of boreal needle trees have been studied quite intensively, there is much less knowledge on the emissions of boreal deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds (OVOCs). Here we quantified the downy birch (Betula pubescens) leaf emissions of terpenes, oxygenated terpenes and green leaf volatiles (GLVs) at the SMEAR II boreal forest site using in situ gas chromatographs with mass spectrometers. Sesquiterpenes (SQTs) and oxygenated sesquiterpenes (OSQTs) were the main emitted compounds. Mean emission rates of SQTs and OSQTs were significantly higher in the early growing season (510 and 650 ng g1 dw h1, respectively) compared to in the main (40 and 130 ng g1 dw h1, respectively) and late (14 and 46 ng g1 dw h1, respectively) periods, indicating that early leaf growth is a strong source of these compounds. The emissions had a very clear diurnal variation with afternoon maxima being on average 4 to 8 times higher than seasonal means for SQTs and OSQTs, respectively. - Caryophyllene and -farnesene were the main SQTs emitted. The main emitted OSQTs were tentatively identified as 14-hydroxy-caryophyllene acetate (M D 262 g mol1) and 6-hydroxy-caryophyllene (M D 220 g mol1). Over the whole growing season, the total MT emissions were only 24% and 17% of the total SQT and OSQT emissions, respectively. A stressed tree growing in a pot was also studied, and high emissions of -farnesene and an unidentified SQT were detected together with high emissions of GLVs. Due to the relatively low volatility and the high reactivity of SQTs and OSQTs, downy birch emissions are expected to have strong impacts on atmospheric chemistry, especially on secondary organic aerosol (SOA) production. © 2021 BMJ Publishing Group. All rights reserved.
语种	英语
scopus关键词	Betula; Betula pubescens
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246861
作者单位	Atmospheric Composition Research Unit, Finnish Meteorological Institute, P.O. Box 503, Helsinki, 00101, Finland; Institute for Atmospheric and Earth System Research/Forest Sciences, Helsinki, Finland; Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland; Department of Forest Ecology and Management, Slu, Umeä, 901 83, Sweden
推荐引用方式 GB/T 7714	Hellén H.,Praplan A.P.,Tykkä T.,et al. Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5-C20) emissions of downy birches[J],2021,21(10).
APA	Hellén H..,Praplan A.P..,Tykkä T..,Helin A..,Schallhart S..,...&Hakola H..(2021).Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5-C20) emissions of downy birches.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(10).
MLA	Hellén H.,et al."Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5-C20) emissions of downy birches".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.10(2021).