scholarly journals Design and characterization of a semi-open dynamic chamber for measuring biogenic volatile organic compound (BVOC) emissions from plants

2022 ◽  
Vol 15 (1) ◽  
pp. 79-93
Author(s):  
Jianqiang Zeng ◽  
Yanli Zhang ◽  
Huina Zhang ◽  
Wei Song ◽  
Zhenfeng Wu ◽  
...  
Keyword(s):  
Organic Compound ◽  
Residence Time ◽  
Volatile Organic Compound ◽  
Mangifera Indica ◽  
Emission Factors ◽  
Residence Times ◽  
Flow Rates ◽  
Dynamic Chamber ◽  
Volatile Organic ◽  
Biogenic Volatile Organic Compound

Abstract. With the accumulation of data about biogenic volatile organic compound (BVOC) emissions from plants based on branch-scale enclosure measurements worldwide, it is vital to assure that measurements are conducted using well-characterized dynamic chambers with good transfer efficiencies and less disturbance on natural growing microenvironments. In this study, a self-made cylindrical semi-open dynamic chamber with a Teflon-coated inner surface was characterized both in the lab with standard BVOC mixtures and in the field with typical broadleaf and coniferous trees. The lab simulation with a constant flow of standard mixtures and online monitoring of BVOCs by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) revealed lower real-time mixing ratios and shorter equilibrium times than theoretically predicted due to wall loss in the chamber and that larger flow rates (shorter residence times) can reduce the adsorptive loss and improve the transfer efficiencies. However, even when flow rates were raised to secure residence times of less than 1 min, transfer efficiencies were still below 70 % for heavier BVOCs like α-pinene and β-caryophyllene. Relative humidity (RH) impacted the adsorptive loss of BVOCs less significantly when compared to flow rates, with compound-specific patterns related to the influence of RH on their adsorption behaviour. When the chamber was applied in the field to a branch of a Mangifera indica tree, the ambient–enclosure temperature differences decreased from 4.5±0.3 to 1.0±0.2 ∘C and the RH differences decreased from 9.8 ± 0.5 % to 1.2±0.1 % as flow rates increased from 3 L min−1 (residence time ∼4.5 min) to 15 L min−1 (residence time ∼0.9 min). At a medium flow rate of 9 L min−1 (residence time ∼1.5 min), field tests with the dynamic chamber for Mangifera indica and Pinus massoniana branches revealed enclosure temperature increase within +2 ∘C and CO2 depletion within −50 ppm when compared to their ambient counterparts. The results suggested that substantially higher air circulating rates would benefit by reducing equilibrium time, adsorptive loss, and the ambient–enclosure temperature and RH differences. However, even under higher air circulating rates and with inert Teflon-coated inner surfaces, the transfer efficiencies for monoterpene and sesquiterpene species are not so satisfactory, implying that emission factors for these species might be underestimated if they are obtained by dynamic chambers without certified transfer efficiencies and that further efforts are needed for field measurements to improve accuracies and narrow the uncertainties of the emission factors.

scholarly journals Design and characterization of a semi-open dynamic chamber for measuring biogenic volatile organic compounds (BVOCs) emissions from plants

2021 ◽  
Author(s):  
Jianqiang Zeng ◽  
Yanli Zhang ◽  
Huina Zhang ◽  
Wei Song ◽  
Zhenfeng Wu ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Residence Time ◽  
Mangifera Indica ◽  
Emission Factors ◽  
Residence Times ◽  
Biogenic Volatile Organic Compounds ◽  
Flow Rates ◽  
Dynamic Chamber ◽  
Volatile Organic

Abstract. With the accumulation of data about biogenic volatile organic compounds (BVOCs) emissions from plants based on branch-scale enclosure measurements worldwide, it is vital to assure that measurements are conducted using well-characterized dynamic chambers with good transfer efficiencies and less disturbance on natural growing microenvironments. In this study, a self-made cylindrical semi-open dynamic chamber with Teflon-coated inner surface was characterized both in the lab with standard BVOC mixtures and in the field with typical broad-leaf and coniferous trees. The lab simulation with a constant flow of standard mixtures and online monitoring of BVOCs by proton transfer-time of flight-mass spectrometry (PTR-ToF-MS) revealed that lower real-time mixing ratios and shorter equilibrium times than theoretically predicted due to wall loss in the chamber, and larger flow rates (shorter residence times) can reduce the absorptive loss and improve the transfer efficiencies. However, even flow rates were raised to secure residence times less than 1 min, transfer efficiencies were still below 70 % for heavier BVOCs like α-pinene and β-caryophyllene. Relative humidity (RH) impacted the adsorptive loss of BVOCs less significantly when compared to flow rates, with compound specific patterns related to the influence of RH on their adsorption behavior. When the chamber was applied in the field to a branch of a mangifera indica tree, the enclosure-ambient temperature differences decreased from 4.5 ± 0.3 to 1.0 ± 0.2 °C and the RH differences decreased from 9.8 ± 0.5 % to 1.2 ± 0.1 % as flow rates increased from 3 L min−1 (residence time ~4.5 min) to 15 L min−1 (residence time ~0.9 min). At a medium flow rate of 9 L min−1 (residence time ~1.5 min), field tests with the dynamic chamber for Mangifera indica and Pinus massoniana branches revealed enclosure temperature increase within +2 °C and CO2 depletion within −50 ppm when compared to their ambient counterparts. The results suggested that substantially higher air circulating rates would benefit reducing equilibrium time, adsorptive loss and the ambient-enclosure temperature/RH differences. However, even under higher air circulating rates and with inert Teflon-coated inner surfaces, the transfer efficiencies for monoterpene and sesquiterpene species are not so satisfactory, implying that emission factors for these species might be underestimated if they are obtained by dynamic chambers without certified transfer efficiencies, and that further efforts are needed for field measurements to improve accuracies and narrow the uncertainties of the emission factors.

scholarly journals A tethered-balloon PTRMS sampling approach for surveying of landscape-scale biogenic VOC fluxes

2014 ◽  
Vol 7 (7) ◽  
pp. 2263-2271 ◽  
Author(s):  
J. P. Greenberg ◽  
J. Peñuelas ◽  
A. Guenther ◽  
R. Seco ◽  
A. Turnipseed ◽  
...  
Keyword(s):  
Organic Compound ◽  
Volatile Organic Compound ◽  
Emission Factors ◽  
Landscape Scale ◽  
Tethered Balloon ◽  
Sampling System ◽  
Short Period ◽  
Wide Range ◽  
Volatile Organic ◽  
Biogenic Volatile Organic Compound

Abstract. Landscape-scale fluxes of biogenic gases were surveyed by deploying a 100 m Teflon tube attached to a tethered balloon as a sampling inlet for a fast-response proton-transfer-reaction mass spectrometer (PTRMS). Along with meteorological instruments deployed on the tethered balloon and a 3 m tripod and outputs from a regional weather model, these observations were used to estimate landscape-scale biogenic volatile organic compound fluxes with two micrometeorological techniques: mixed layer variance and surface layer gradients. This highly mobile sampling system was deployed at four field sites near Barcelona to estimate landscape-scale biogenic volatile organic compound (BVOC) emission factors in a relatively short period (3 weeks). The two micrometeorological techniques were compared with emissions predicted with a biogenic emission model using site-specific emission factors and land-cover characteristics for all four sites. The methods agreed within the uncertainty of the techniques in most cases, even though the locations had considerable heterogeneity in species distribution and complex terrain. Considering the wide range in reported BVOC emission factors for individual vegetation species (more than an order of magnitude), this temporally short and inexpensive flux estimation technique may be useful for constraining BVOC emission factors used as model inputs.

Non-Methane Biogenic Volatile Organic Compound Emissions from a Subarctic Peatland Under Enhanced UV-B Radiation

Ecosystems ◽  
2010 ◽  
Vol 13 (6) ◽  
pp. 860-873 ◽  
Author(s):  
Patrick Faubert ◽  
Päivi Tiiva ◽  
Åsmund Rinnan ◽  
Janne Räsänen ◽  
Jarmo K. Holopainen ◽  
...  
Keyword(s):  
Organic Compound ◽  
Volatile Organic Compound ◽  
Volatile Organic ◽  
Volatile Organic Compound Emissions ◽  
Biogenic Volatile Organic Compound

scholarly journals Leaf-Scale Study of Biogenic Volatile Organic Compound Emissions from Willow (Salix spp.) Short Rotation Coppices Covering Two Growing Seasons

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1427
Author(s):  
Tomas Karlsson ◽  
Leif Klemedtsson ◽  
Riikka Rinnan ◽  
Thomas Holst
Keyword(s):  
Organic Compound ◽  
Volatile Organic Compound ◽  
Large Scale ◽  
Response Curves ◽  
Growing Seasons ◽  
Short Rotation ◽  
Canopy Position ◽  
Volatile Organic ◽  
Biogenic Volatile Organic Compound ◽  
Salix Spp

In Europe, willow (Salix spp.) trees have been used commercially since the 1980s at a large scale to produce renewable energy. While reducing fossil fuel needs, growing short rotation coppices (SRCs), such as poplar or willow, may have a high impact on local air quality as these species are known to produce high amounts of isoprene, which can lead to the production of tropospheric ozone (O3). Here, we present a long-term leaf-scale study of biogenic volatile organic compound (BVOC) emissions from a Swedish managed willow site with the aim of providing information on the seasonal variability in BVOC emissions during two growing seasons, 2015–2016. Total BVOC emissions during these two seasons were dominated by isoprene (>96% by mass) and the monoterpene (MT) ocimene. The average standardized (STD, temperature of 30 °C and photosynthetically active radiation of 1000 µmol m−2 s−1) emission rate for isoprene was 45.2 (±42.9, standard deviation (SD)) μg gdw−1 h−1. Isoprene varied through the season, mainly depending on the prevailing temperature and light, where the measured emissions peaked in July 2015 and August 2016. The average STD emission for MTs was 0.301 (±0.201) μg gdw−1 h−1 and the MT emissions decreased from spring to autumn. The average STD emission for sesquiterpenes (SQTs) was 0.103 (±0.249) μg gdw−1 h−1, where caryophyllene was the most abundant SQT. The measured emissions of SQTs peaked in August both in 2015 and 2016. Non-terpenoid compounds were grouped as other VOCs (0.751 ± 0.159 μg gdw−1 h−1), containing alkanes, aldehydes, ketones, and other compounds. Emissions from all the BVOC groups decreased towards the end of the growing season. The more sun-adapted leaves in the upper part of the plantation canopy emitted higher rates of isoprene, MTs, and SQTs compared with more shade-adapted leaves in the lower canopy. On the other hand, emissions of other VOCs were lower from the upper part of the canopy compared with the lower part. Light response curves showed that ocimene and α-farnesene increased with light but only for the sun-adapted leaves, since the shade-adapted leaves did not emit ocimene and α-farnesene. An infestation with Melampsora spp. likely induced high emissions of, e.g., hexanal and nonanal in August 2015. The results from this study imply that upscaling BVOC emissions with model approaches should account for seasonality and also include the canopy position of leaves as a parameter to allow for better estimates for the regional and global budgets of ecosystem emissions.

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