scholarly journals Sesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C<sub>5</sub>–C<sub>20</sub>) emissions of downy birches

2021 ◽  
Vol 21 (10) ◽  
pp. 8045-8066
Author(s):  
Heidi Hellén ◽  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Aku Helin ◽  
Simon Schallhart ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Leaf Growth ◽  
Growing Season ◽  
Green Leaf Volatiles ◽  
Forest Site ◽  
Leaf Volatiles ◽  
Volatile Organic ◽  
Downy Birch

Abstract. 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 gdw-1 h−1, respectively) compared to in the main (40 and 130 ng gdw-1 h−1, respectively) and late (14 and 46 ng gdw-1 h−1, 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. β-Caryophyllene and β-farnesene were the main SQTs emitted. The main emitted OSQTs were tentatively identified as 14-hydroxy-β-caryophyllene acetate (M=262 g mol−1) and 6-hydroxy-β-caryophyllene (M=220 g mol−1). 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 α-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.

scholarly journals Sesquiterpenes and oxygenated sesquiterpenes dominate the emissions of downy birches

2020 ◽  
Author(s):  
Heidi Hellén ◽  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Aku Helin ◽  
Simon Schallhart ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Growing Season ◽  
Green Leaf Volatiles ◽  
Forest Site ◽  
Bud Break ◽  
Mass Spectrometers ◽  
Leaf Volatiles ◽  
Strong Source ◽  
Downy Birch

Abstract. Even though isoprene and monoterpene (MT) emissions of boreal needle trees have been studied quite intensively, there is less knowledge on the emissions of broadleaved deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds (OVOCs). Here we studied the downy birch (Betula pubescens) leaf emissions of terpenes, OVOCs and green leaf volatiles (GLVs) at the SMEAR II boreal forest site using in situ gas chromatographs with mass spectrometers in 2017 and 2019. The highest emissions were detected during the early growing season, indicating that bud break and early leaf growth are a strong source of these compounds. Sesquiterpenes (SQTs) and oxygenated sesquiterpenes (OSQTs) were the main emitted compounds almost throughout the summer. Mean emissions (averaged over bud break/early/main and late growing season) of SQTs and OSQTs were 5–690 and 46–650 ng gdw−1 h−1, respectively. Isoprene emissions were very low or below detection limits (seasonal means

Variability of overhead volatile organic compounds in clonal tea (Camellia sinensis) and their influence on red crevice mite (Brevipalpus phoenicis Geijskes) infestations

2016 ◽  
Author(s):  
Jenipher A. Odak ◽  
P. Okinda Owuora ◽  
Lawrence O.A. Mang’uro ◽  
Evelyn Cheramgoi ◽  
And Francis N. Wachira
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Aromatic Compounds ◽  
Green Leaf Volatiles ◽  
Leaf Volatiles ◽  
Hexenyl Acetate ◽  
Volatile Organic ◽  
Brevipalpus Phoenicis ◽  
Tea Production ◽  
Breeding Selection

Tea production in Kenya is under threat due to red crevice mites (Brevipalpus phoenicis) infestations during droughts. Cultural pests control practices, e.g. use of resistant/tolerant cultivars are used in their control since pesticide use is prohibited. Plants release volatile organic compounds (OVOCs) that may influence susceptibility/resistance to pest infestations. OVOCs profiles released by 11 tea cultivars were evaluated to assess relationship between OVOCs and cultivar tolerance/susceptibility to B. phoenicis. Five clones were susceptible, with high B. phoenicis infestations while four clones were resistant, exhibiting low infestation levels. The infestations were linearly correlated to (E)-2-hexenal, (Z)-3-hexenal (p≤0.001), (Z)-3-hexenol, (Z)-3-hexenyl acetate, linalool, germacrene D, sum of green leaf volatiles (GLVs) (p≤0.01), 1-pentene-3-ol, hexanal, indole and (E)-β-ocimene (p≤0.05) levels. Most of aromatic compounds, some terpenoids compounds and sum of aromatic compounds were inversely (p≤0.05) correlated with B. phoenicis infestations. Susceptible varieties to B. phoenicis emitted high amounts of GLVs, especially (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate. Results demonstrate that OVOCs profile may provide selection criteria for cultivars resistant to B. phoenicis infestations. Resistant cultivars are recommended for commercial exploitation in red crevice mites prone areas while breeding/selection programmes should incorporate OVOCs profiles to develop tea cultivars that resist red crevice mites attack.

scholarly journals Mānuka Clones Differ in Their Volatile Profiles: Potential Implications for Plant Defence, Pollinator Attraction and Bee Products

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 169
Author(s):  
Evans Effah ◽  
Kyaw Min Tun ◽  
Natalia Rangiwananga ◽  
Andrea Clavijo McCormick
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Antioxidant Properties ◽  
Plant Defence ◽  
Green Leaf Volatiles ◽  
Gas Chromatography Mass Spectrometry ◽  
Native Plant ◽  
Pollinator Attraction ◽  
Leaf Volatiles ◽  
Volatile Organic

The New Zealand native plant mānuka (Leptospermum scoparium) is representative of the country’s North and South Islands flora. This species is essential to the growing community of honey producers due to its honey’s antimicrobial and antioxidant properties, attributed to the presence of methylglyoxal (MGO), derived from dihydroxyacetone (DHA) in the nectar. Several clones and cultivars have been selected to optimize DHA production. Still, nothing is known about the volatile emissions of these artificially selected plants. Volatile organic compounds (VOCs) can influence their interactions with the environment, such as pollinator foraging decisions, which may subsequently affect the plants’ products. This study explored the aboveground volatile organic compounds (VOCs) emitted by eight different mānuka genotypes (six clones and two wild cultivars) under field conditions during the spring season. Volatiles were collected using the “push–pull” headspace sampling technique and analyzed using gas chromatography-mass spectrometry (GC-MS). Our results show that mānuka plants emit large amounts of terpenoids, with sesquiterpenes and monoterpenoids being the most abundant groups of compounds. The results also show variation in the total green leaf volatiles, total sesquiterpenes, and specific compounds between genotypes and suggest that artificially selected plants have a significant variation in their chemical profiles. The potential impacts of these results on the plant’s defence, pollinator attraction and bee products are discussed.

scholarly journals Long-term measurements of volatile organic compounds highlight the importance of sesquiterpenes for the atmospheric chemistry of a boreal forest

2018 ◽  
Vol 18 (19) ◽  
pp. 13839-13863 ◽  
Author(s):  
Heidi Hellén ◽  
Arnaud P. Praplan ◽  
Toni Tykkä ◽  
Ilona Ylivinkka ◽  
Ville Vakkari ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Boreal Forest ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Vertical Mixing ◽  
Diurnal Variations ◽  
Oxidation Products ◽  
Forest Site ◽  
Seasonal And Diurnal Variations ◽  
Volatile Organic

Abstract. The concentrations of terpenoids (isoprene; monoterpenes, MTs; and sesquiterpenes, SQTs) and oxygenated volatile organic compounds (OVOCs; i.e. aldehydes, alcohols, acetates and volatile organic acids, VOAs) were investigated during 2 years at a boreal forest site in Hyytiälä, Finland, using in situ gas chromatograph mass spectrometers (GC-MSs). Seasonal and diurnal variations of terpenoid and OVOC concentrations as well as their relationship with meteorological factors were studied. Of the VOCs examined, C2–C7 unbranched VOAs showed the highest concentrations, mainly due to their low reactivity. Of the terpenoids, MTs showed the highest concentrations at the site, but seven different highly reactive SQTs were also detected. The monthly and daily mean concentrations of most terpenoids, aldehydes and VOAs were highly dependent on the temperature. The highest exponential correlation with temperature was found for a SQT (β-caryophyllene) in summer. The diurnal variations in the concentrations could be explained by sources, sinks and vertical mixing. The diurnal variations in MT concentrations were strongly affected by vertical mixing. Based on the temperature correlations and mixing layer height (MLH), simple proxies were developed for estimating the MT and SQT concentrations. To estimate the importance of different compound groups and compounds in local atmospheric chemistry, reactivity with main oxidants (hydroxyl radical, OH; nitrate radical, NO3; and ozone, O3) and production rates of oxidation products (OxPRs) were calculated. The MTs dominated OH and NO3 radical chemistry, but the SQTs greatly impacted O3 chemistry, even though the concentrations of SQT were 30 times lower than the MT concentrations. SQTs were also the most important for the production of oxidation products. Since the SQTs show high secondary organic aerosol (SOA) yields, the results clearly indicate the importance of SQTs for local SOA production.

A Future Multi-Platform Atmospheric Chemistry Measurement Campaign to Study Oxidation in Mixed Anthropogenic-Biogenic Air Masses

2021 ◽  
Author(s):  
Christopher Cantrell ◽  
Vincent Michoud ◽  
Paola Formenti ◽  
Jean-Francois Doussin ◽  
Stephanie Alhajj Moussa ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Los Angeles ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Vapor Pressures ◽  
Air Masses ◽  
Measurement Campaign ◽  
Secondary Species ◽  
Volatile Organic ◽  
Urban Plumes

&lt;p&gt;It is well known that the high population density of urban regions leads to significant degradation of the quality of the air because of the emissions of pollutants that are by-products of energy production, transportation, and industry. The composition and chemistry of urban air has been studied for many decades and these studies have led to detailed understanding of the factors controlling, for example, the formation of ozone, peroxyacetyl nitrate and other secondary species. In the last 20 to 30 years, significant progress has been made in reducing emissions of volatile organic compounds (VOCs) and oxides of nitrogen (NO&lt;sub&gt;x&lt;/sub&gt;) in urban atmospheres. Substantial reductions in the abundance of secondary compounds, though, have been more elusive.&lt;/p&gt;&lt;p&gt;Research has continued to reveal more and more details of the complex processes involved in the atmospheric degradation of wide varieties of volatile organic compounds (VOCs) of anthropogenic and biospheric (BVOCs) origins. BVOCs include isoprene, monoterpenes and sesquiterpenes, and oxygenated VOCs (OVOCs, such as small alcohols). Emissions of BVOCs depend on several factors such as plant or tree species, temperature, and photosynthetically active radiation. They consist almost exclusively of unsaturated compounds with chemistry somewhat different from those of typical urban organic compound emissions. Oxidation of VOCs can lead to molecules of low volatility that are prone to uptake into the aerosol phase.&lt;/p&gt;&lt;p&gt;Recent studies conducted in megacities such as Paris, Mexico City, Los Angeles and those in China have led to significant advances in our understanding of the chemical evolution of urban plumes. However, important scientific questions remain on how mixing of anthropogenic and biogenic air masses modifies the composition of urban plumes and hence their impacts. Indeed, the proximity of cites to areas of strong biogenic emissions is not unusual. Many major cities at mid-latitudes are surrounded by forested areas.&lt;/p&gt;&lt;p&gt;ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) is an integrative, innovative, multi-scale project awarded under the &amp;#8220;Make Our Planet Great Again&amp;#8221; (MOPGA) framework that seeks to definitively improve understanding of the impacts of mixing urban and biogenic air masses on the oxidation of atmospheric VOCs. The ACROSS working hypothesis is that this leads to changes in the production of oxygenated VOCs whose properties (e.g. vapor pressures) alter their importance in incorporation into SOA and their roles in production of ozone and other secondary species. Changes are also expected in the efficiency of radical recycling affecting the atmospheric oxidative capacity. Particularly important is NO&lt;sub&gt;x&lt;/sub&gt; transport to suburban biogenic environments and the resulting modification of key chemical processes.&lt;/p&gt;&lt;p&gt;A key highlight of ACROSS is an intensive, multi-platform measurement campaign in the summer of 2022. It will use instruments staged on an airborne platform, a tower in the Rambouillet Forest near Paris, and other ground sites. The data collected from this campaign will be analyzed and studied to extract information about tropospheric oxidation chemistry generally, but also changes observed in the situation of mixed urban and biogenic air masses.&lt;/p&gt;&lt;p&gt;This presentation will summarize plans for the ACROSS campaign.&lt;/p&gt;

Variation of atmospheric volatile organic compounds over the Southern Indian Ocean (30 - 49°S)

2009 ◽  
Vol 6 (1) ◽  
pp. 70 ◽  
Author(s):  
Aurélie Colomb ◽  
Valérie Gros ◽  
Séverine Alvain ◽  
Roland Sarda-Esteve ◽  
Bernard Bonsang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Indian Ocean ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Marine Boundary Layer ◽  
Global Scale ◽  
Climate Impacts ◽  
Southern Indian Ocean ◽  
Oceanic Fronts ◽  
Volatile Organic

Environmental context. Oceans represent 70% of the blue planet, and surprisingly, ocean emission in term of volatile organic compounds is poorly understood. The potential climate impacts on a global scale of various trace organic gases have been established, and the terrestrial inputs are well studied, but little is known about which of these can be emitted from oceanic sources. In the present study, atmospheric samples were taken over the Southern Indian Ocean, while crossing some oceanic fronts and different phytoplankton species. Such a study should aid in understanding oceanic emission, especially from phytoplankton, and will help modellers to determine concentrations of organic traces in the remote marine troposphere. Abstract. Considering its size and potential importance, the ocean is poorly characterised in terms of volatile organic compounds (VOC) that play important roles in global atmospheric chemistry. In order to better understand their potential sources and sinks over the Southern Indian Austral Ocean, shipborne measurements of selected species were made during the MANCHOT campaign during December 2004, on board the research vessel Marion Dufresne. Along the transect La Réunion to Kerguelen Island, air measurements of selected VOC (including dimethylsulfide (DMS) isoprene, carbonyls and organohalogens), carbon monoxide and ozone were performed, crossing subtropical, temperate and sub-Antarctic waters as well as pronounced subtropical and sub-Antarctic oceanic fronts. The remote marine boundary layer was characterised at latitudes 45–50°S. Oceanic fronts were associated with enhanced chlorophyll and biological activity in the seawater and elevated DMS and organohalogens in the atmosphere. These were compared with a satellite-derived phytoplankton distribution (PHYSAT). Diurnal variation for isoprene, terpenes, acetone and acetaldehyde was observed, analogously to recent results observed in mesocosm experiments.

scholarly journals Physicochemical uptake and release of volatile organic compounds by soil in coated-wall flow tube experiments with ambient air

2019 ◽  
Vol 19 (4) ◽  
pp. 2209-2232 ◽  
Author(s):  
Guo Li ◽  
Yafang Cheng ◽  
Uwe Kuhn ◽  
Rongjuan Xu ◽  
Yudong Yang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Soil Surface ◽  
Ambient Air ◽  
Flow Tube ◽  
Heterogeneous Oxidation ◽  
Volatile Organic ◽  
Wall Flow

Abstract. Volatile organic compounds (VOCs) play a key role in atmospheric chemistry. Emission and deposition on soil have been suggested as important sources and sinks of atmospheric trace gases. The exchange characteristics and heterogeneous chemistry of VOCs on soil, however, are not well understood. We used a newly designed differential coated-wall flow tube system to investigate the long-term variability of bidirectional air–soil exchange of 13 VOCs under ambient air conditions of an urban background site in Beijing. Sterilized soil was investigated to address physicochemical processes and heterogeneous/multiphase reactions independently from biological activity. Most VOCs revealed net deposition with average uptake coefficients (γ) in the range of 10−7–10−6 (referring to the geometric soil surface area), corresponding to deposition velocities (Vd) of 0.0013–0.01 cm s−1 and soil surface resistances (Rc) of 98–745 s cm−1, respectively. Formic acid, however, was emitted at a long-term average rate of ∼6×10-3 nmol m−2 s−1, suggesting that it was formed and released upon heterogeneous oxidation of other VOCs. The soil–atmosphere exchange of one individual VOC species can be affected by both its surface degradation/depletion caused by surface reactions and by competitive uptake or heterogeneous formation/accommodation of other VOC species. Overall, the results show that physicochemical processing and heterogeneous oxidation on soil and soil-derived dust can act as a sink or as a source of atmospheric VOCs, depending on molecular properties and environmental conditions.

scholarly journals Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms and organic aerosol

2016 ◽  
Author(s):  
N. L. Ng ◽  
S. S. Brown ◽  
A. T. Archibald ◽  
E. Atlas ◽  
R. C. Cohen ◽  
...  
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Climate Models ◽  
Large Body ◽  
Organic Aerosol ◽  
Organic Nitrate ◽  
Biogenic Volatile Organic Compounds ◽  
Volatile Organic

Abstract. Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than three decades, during which time a large body of research has emerged from laboratory, field and modeling studies. NO3-BVOC reactions influence air quality, climate and visibility through regional and global budgets for reactive nitrogen (particularly organic nitrates), ozone and organic aerosol. Despite its long history of research and the significance of this topic in atmospheric chemistry, a number of important uncertainties remain. These include an incomplete understanding of the rates, mechanisms and organic aerosol yields for NO3-BVOC reactions, lack of constraints on the role of heterogeneous oxidative processes associated with the NO3 radical, the difficulty of characterizing the spatial distributions of BVOC and NO3 within the poorly mixed nocturnal atmosphere and the challenge of constructing appropriate boundary layer schemes and non-photochemical mechanisms for use in state-of-the-art chemical transport and chemistry-climate models. This review is the result of a workshop of the same title held at the Georgia Institute of Technology in June 2015. The first section summarizes the current literature on NO3-BVOC chemistry, with a particular focus on recent advances in instrumentation and models, and in organic nitrate and secondary organic aerosol (SOA) formation chemistry. Building on this current understanding, the second half of the review outlines impacts of NO3-BVOC chemistry on air quality and climate, and suggests critical research needs to better constrain this interaction to improve the predictive capabilities of atmospheric models.

scholarly journals Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

2010 ◽  
Vol 10 (17) ◽  
pp. 8391-8412 ◽  
Author(s):  
B. Langford ◽  
P. K. Misztal ◽  
E. Nemitz ◽  
B. Davison ◽  
C. Helfter ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Tropical Forests ◽  
Atmospheric Chemistry ◽  
Carbon Flux ◽  
Tropical Rainforest ◽  
East Asian ◽  
Emission Rates ◽  
Reactive Carbon ◽  
Volatile Organic

Abstract. As part of the OP3 field study of rainforest atmospheric chemistry, above-canopy fluxes of isoprene, monoterpenes and oxygenated volatile organic compounds were made by virtual disjunct eddy covariance from a South-East Asian tropical rainforest in Malaysia. Approximately 500 hours of flux data were collected over 48 days in April–May and June–July 2008. Isoprene was the dominant non-methane hydrocarbon emitted from the forest, accounting for 80% (as carbon) of the measured emission of reactive carbon fluxes. Total monoterpene emissions accounted for 18% of the measured reactive carbon flux. There was no evidence for nocturnal monoterpene emissions and during the day their flux rate was dependent on both light and temperature. The oxygenated compounds, including methanol, acetone and acetaldehyde, contributed less than 2% of the total measured reactive carbon flux. The sum of the VOC fluxes measured represents a 0.4% loss of daytime assimilated carbon by the canopy, but atmospheric chemistry box modelling suggests that most (90%) of this reactive carbon is returned back to the canopy by wet and dry deposition following chemical transformation. The emission rates of isoprene and monoterpenes, normalised to 30 °C and 1000 μmol m−2 s−1 PAR, were 1.6 mg m−2 h−1 and 0.46mg m−2 h−1 respectively, which was 4 and 1.8 times lower respectively than the default value for tropical forests in the widely-used MEGAN model of biogenic VOC emissions. This highlights the need for more direct canopy-scale flux measurements of VOCs from the world's tropical forests.

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