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Liu X, Qiao S, Ma Y. Highly sensitive methane detection based on light-induced thermoelastic spectroscopy with a 2.33 µm diode laser and adaptive Savitzky-Golay filtering. OPTICS EXPRESS 2022; 30:1304-1313. [PMID: 35209293 DOI: 10.1364/oe.446294] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
In this manuscript, a highly sensitive methane (CH4) sensor based on light-induced thermoelastic spectroscopy (LITES) using a 2.33 µm diode laser with high power is demonstrated for the first time. A quartz tuning fork (QTF) with an intrinsic resonance frequency of 32.768 kHz was used to detect the light-induced thermoelastic signal. A Herriot multi-pass cell with an effective optical path of 10 m was adopted to increase the laser absorption. The laser wavelength modulation depth and concentration response of this CH4-LITES sensor were investigated. The sensor showed excellent long term stability when Allan deviation analysis was performed. An adaptive Savitzky-Golay (S-G) filtering algorithm with χ2 statistical criterion was firstly introduced to the LITES technique. The SNR of this CH4-LITES sensor was improved by a factor of 2.35 and the minimum detection limit (MDL) with an integration time of 0.1 s was optimized to 0.5 ppm. This reported CH4-LITES sensor with sub ppm-level detection ability is of great value in applications such as environmental monitoring and industrial safety.
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Covey KR, Megonigal JP. Methane production and emissions in trees and forests. THE NEW PHYTOLOGIST 2019; 222:35-51. [PMID: 30521089 DOI: 10.1111/nph.15624] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 10/21/2018] [Indexed: 06/09/2023]
Abstract
Contents Summary 35 I. Introduction 36 II. Tree CH4 fluxes 36 III. Tree emissions of soil-produced CH4 40 IV. Tree-produced CH4 42 V. Trees in forest CH4 budgets 44 VI. Conclusions 46 Acknowledgements 48 Author contributions 48 References 48 SUMMARY: Forest ecosystem methane (CH4 ) research has focused on soils, but trees are also important sources and sinks in forest CH4 budgets. Living and dead trees transport and emit CH4 produced in soils; living trees and dead wood emit CH4 produced inside trees by microorganisms; and trees produce CH4 through an abiotic photochemical process. Here, we review the state of the science on the production, consumption, transport, and emission of CH4 by living and dead trees, and the spatial and temporal dynamics of these processes across hydrologic gradients inclusive of wetland and upland ecosystems. Emerging research demonstrates that tree CH4 emissions can significantly increase the source strength of wetland forests, and modestly decrease the sink strength of upland forests. Scaling from stem or leaf measurements to trees or forests is limited by knowledge of the mechanisms by which trees transport soil-produced CH4 , microbial processes produce and oxidize CH4 inside trees, a lack of mechanistic models, the diffuse nature of forest CH4 fluxes, complex overlap between sources and sinks, and extreme variation across individuals. Understanding the complex processes that regulate CH4 source-sink dynamics in trees and forests requires cross-disciplinary research and new conceptual models that transcend the traditional binary classification of wetland vs upland forest.
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Affiliation(s)
- Kristofer R Covey
- Environmental Studies and Sciences Program, Skidmore College, 815 N Broadway, Saratoga Springs, NY, 12866, USA
- School of Forestry and Environmental Studies, Yale University, 195 Prospect St., New Haven, CT, 06511, USA
| | - J Patrick Megonigal
- Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD, 21037, USA
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Bruhn D, Møller IM, Mikkelsen TN, Ambus P. Terrestrial plant methane production and emission. PHYSIOLOGIA PLANTARUM 2012; 144:201-209. [PMID: 22136562 DOI: 10.1111/j.1399-3054.2011.01551.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH(4) ) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH(4) production, i.e. cutting injuries, increasing temperature, ultraviolet radiation and reactive oxygen species. Further, we analyze rates of measured emission of aerobically produced CH(4) in pectin and in plant tissues from different studies and argue that pectin is very far from the sole contributing precursor. In consequence, scaling up of aerobic CH(4) emission needs to take into consideration other potential sources than pectin. Due to the large uncertainties related to effects of stimulating factors, genotypic responses and type of precursors, we conclude that current attempts for upscaling aerobic CH(4) into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH(4) precursors in plant material.
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Affiliation(s)
- Dan Bruhn
- Risø National Laboratory for Sustainable Energy, Technical university of Denmark, Biosystems Division, BIO-309, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
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Bloom AA, Palmer PI, Fraser A, Reay DS, Frankenberg C. Large-scale controls of methanogenesis inferred from methane and gravity spaceborne data. Science 2010; 327:322-5. [PMID: 20075250 DOI: 10.1126/science.1175176] [Citation(s) in RCA: 269] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Wetlands are the largest individual source of methane (CH4), but the magnitude and distribution of this source are poorly understood on continental scales. We isolated the wetland and rice paddy contributions to spaceborne CH4 measurements over 2003-2005 using satellite observations of gravity anomalies, a proxy for water-table depth Gamma, and surface temperature analyses TS. We find that tropical and higher-latitude CH4 variations are largely described by Gamma and TS variations, respectively. Our work suggests that tropical wetlands contribute 52 to 58% of global emissions, with the remainder coming from the extra-tropics, 2% of which is from Arctic latitudes. We estimate a 7% rise in wetland CH4 emissions over 2003-2007, due to warming of mid-latitude and Arctic wetland regions, which we find is consistent with recent changes in atmospheric CH4.
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Affiliation(s)
- A Anthony Bloom
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
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Bruhn D, Mikkelsen TN, Obro J, Willats WGT, Ambus P. Effects of temperature, ultraviolet radiation and pectin methyl esterase on aerobic methane release from plant material. PLANT BIOLOGY (STUTTGART, GERMANY) 2009; 11 Suppl 1:43-48. [PMID: 19778367 DOI: 10.1111/j.1438-8677.2009.00202.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This study examines the effects of different irradiance types on aerobic methane (CH(4)) efflux rates from terrestrial plant material. Furthermore, the role of the enzyme pectin methyl esterase (PME) on CH(4) efflux potential was also examined. Different types of plant tissue and purified pectin were incubated in glass vials with different combinations of irradiation and/or temperature. Purified dry pectin was incubated in solution, and with or without PME. Before and after incubation, the concentration of CH(4) was measured with a gas chromatograph. Rates of CH(4) emission were found to depend exponentially on temperature and linearly on UV-B irradiance. UV-B had a greater stimulating effect than UV-A, while visible light had no effect on emission rates. PME was found to substantially reduce the potential for aerobic CH(4) emissions upon demethylation of pectin.
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Affiliation(s)
- D Bruhn
- Ecosystems Programme, Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde, Denmark.
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Andrady A, Aucamp PJ, Bais A, Ballaré CL, Björn LO, Bornman JF, Caldwell M, Cullen AP, Erickson DJ, de Gruijl FR, Häder DP, Ilyas M, Kulandaivelu G, Kumar HD, Longstreth J, McKenzie RL, Norval M, Paul N, Redhwi HH, Smith RC, Solomon KR, Sulzberger B, Takizawa Y, Tang X, Teramura AH, Torikai A, van der Leun JC, Wilson SR, Worrest RC, Zepp RG. Environmental effects of ozone depletion and its interactions with climate change: progress report, 2008. Photochem Photobiol Sci 2009; 8:13-22. [PMID: 19256109 DOI: 10.1039/b820432m] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
After the enthusiastic celebration of the 20th Anniversary of the Montreal Protocol on Substances that Deplete the Ozone Layer in 2007, the work for the protection of the ozone layer continues. The Environmental Effects Assessment Panel is one of the three expert panels within the Montreal Protocol. This EEAP deals with the increase of the UV irradiance on the Earth's surface and its effects on human health, animals, plants, biogeochemistry, air quality and materials. For the past few years, interactions of ozone depletion with climate change have also been considered. It has become clear that the environmental problems will be long-lasting. In spite of the fact that the worldwide production of ozone depleting chemicals has already been reduced by 95%, the environmental disturbances are expected to persist for about the next half a century, even if the protective work is actively continued, and completed. The latest full report was published in Photochem. Photobiol. Sci., 2007, 6, 201-332, and the last progress report in Photochem. Photobiol. Sci., 2008, 7, 15-27. The next full report on environmental effects is scheduled for the year 2010. The present progress report 2008 is one of the short interim reports, appearing annually.
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Keppler F, Hamilton JTG, McRoberts WC, Vigano I, Braß M, Röckmann T. Methoxyl groups of plant pectin as a precursor of atmospheric methane: evidence from deuterium labelling studies. THE NEW PHYTOLOGIST 2008; 178:808-814. [PMID: 18346110 DOI: 10.1111/j.1469-8137.2008.02411.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
* The observation that plants produce methane (CH4) under aerobic conditions has caused considerable controversy among the scientific community and the general public. It led to much discussion and debate not only about its contribution to the global CH4 budget but also about the authenticity of the observation itself. Previous results suggested that methoxyl groups of the abundant plant structural component pectin might play a key role in the in situ formation process of CH4. Here, this effect is investigated using an isotope labelling study. * Polysaccharides, pectin and polygalacturonic acid, with varying degrees of trideuterium-labelled methyl groups in the methoxyl moieties, were investigated for CH4 formation under UV irradiation and heating. * A strong deuterium signal in the emitted CH4 was observed from these labelled polysaccharides. * Results clearly demonstrate that ester methyl groups of pectin can serve as a precursor of CH4, supporting the idea of a novel chemical route of CH4 formation in plants under oxic environmental conditions.
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Affiliation(s)
- Frank Keppler
- Max-Planck-Institute for Chemistry, Joh.-Joachim-Becher-Weg 2, 55128 Mainz, Germany
| | - John T G Hamilton
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK
| | - W Colin McRoberts
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, UK
| | - Ivan Vigano
- Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands
| | - Marc Braß
- Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands
| | - Thomas Röckmann
- Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584CC Utrecht, the Netherlands
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