Articles | Volume 13, issue 6
https://doi.org/10.5194/bg-13-1919-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-13-1919-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
30 Mar 2016
Research article |
| 30 Mar 2016
Low methane (CH4) emissions downstream of a monomictic subtropical hydroelectric reservoir (Nam Theun 2, Lao PDR)
Chandrashekhar Deshmukh
Université de Toulouse, UPS GET, 14 Avenue E. Belin, 31400
Toulouse, France
Laboratoire d'Aérologie, Université de
Toulouse, CNRS UMR5560, 14 Av. Edouard Belin, 31400, Toulouse, France
Centre for Regulatory and Policy Research, TERI University, New
Delhi, India
now at: Nam Theun 2 Power Company Limited
(NTPC), Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane, Lao PDR
Université de Toulouse, UPS GET, 14 Avenue E. Belin, 31400
Toulouse, France
Institut de Recherche pour le Développement (IRD),
UR234, GET; 14 Avenue E. Belin, 31400, Toulouse, France
Departamento de Geoquimica, Universidade Federal Fluminense,
Niteroi-RJ, Brazil
David Labat
Université de Toulouse, UPS GET, 14 Avenue E. Belin, 31400
Toulouse, France
Sylvie Pighini
Nam Theun 2 Power Company Limited (NTPC),
Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane,
Lao PDR
now at: Innsbruck University, Institute of Ecology, 15
Sternwartestrasse, 6020 Innsbruck, Austria and Foundation
Edmund Mach, FOXLAB-FEM, Via E. Mach 1, 38010 San Michele all'Adige, Italy
Axay Vongkhamsao
Nam Theun 2 Power Company Limited (NTPC),
Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane,
Lao PDR
Pierre Guédant
Nam Theun 2 Power Company Limited (NTPC),
Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane,
Lao PDR
Wanidaporn Rode
Nam Theun 2 Power Company Limited (NTPC),
Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane,
Lao PDR
Arnaud Godon
Nam Theun 2 Power Company Limited (NTPC),
Environment & Social Division, Water Quality and
Biodiversity Dept., Gnommalath Office, PO Box 5862, Vientiane,
Lao PDR
now at: Arnaud Godon Company, 44 Route de Genas, Nomade Lyon, 69003
Lyon, France
Vincent Chanudet
Electricité de France, Hydro Engineering Centre,
Sustainable Development Dpt, Savoie Technolac, 73373 Le
Bourget du Lac, France
Stéphane Descloux
Electricité de France, Hydro Engineering Centre,
Sustainable Development Dpt, Savoie Technolac, 73373 Le
Bourget du Lac, France
Dominique Serça
Laboratoire d'Aérologie, Université de
Toulouse, CNRS UMR5560, 14 Av. Edouard Belin, 31400, Toulouse, France
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Biogeosciences, 13, 3647–3663, https://doi.org/10.5194/bg-13-3647-2016, https://doi.org/10.5194/bg-13-3647-2016, 2016
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Methane (CH4) emissions from hydroelectric reservoirs could represent a significant fraction of global CH4 emissions from inland waters. The monitoring of methane emissions every 2 weeks at nine stations in a subtropical hydroelectric reservoir revealed that emissions could occasionally be 1 to 2 orders of magnitude higher than expected for these man-made ecosystems. Upstream of the water intake, emissions are enhanced by the water column mixing that upwells CH4-rich water to the surface.
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Olivia Desgué-Itier, Laura Melo Vieira Soares, Orlane Anneville, Damien Bouffard, Vincent Chanudet, Pierre Alain Danis, Isabelle Domaizon, Jean Guillard, Théo Mazure, Najwa Sharaf, Frédéric Soulignac, Viet Tran-Khac, Brigitte Vinçon-Leite, and Jean-Philippe Jenny
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Claire Delon, Corinne Galy-Lacaux, Dominique Serça, Erwan Personne, Eric Mougin, Marcellin Adon, Valérie Le Dantec, Benjamin Loubet, Rasmus Fensholt, and Torbern Tagesson
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Chandrashekhar Deshmukh, Frédéric Guérin, Axay Vongkhamsao, Sylvie Pighini, Phetdala Oudone, Saysoulinthone Sopraseuth, Arnaud Godon, Wanidaporn Rode, Pierre Guédant, Priscia Oliva, Stéphane Audry, Cyril Zouiten, Corinne Galy-Lacaux, Henri Robain, Olivier Ribolzi, Arun Kansal, Vincent Chanudet, Stéphane Descloux, and Dominique Serça
Biogeosciences, 15, 1775–1794, https://doi.org/10.5194/bg-15-1775-2018, https://doi.org/10.5194/bg-15-1775-2018, 2018
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Based on an intense monitoring of CO2 concentrations and organic and inorganic carbon in the reservoir, in the rivers upstream and downstream, and of CO2 emissions from the drawdown area, we confirmed the importance of the flooded stock of organic matter as a source of C fueling emissions and we show that the drawdown area contributes, depending on the year, from 50 to 75 % of total annual gross emissions in the flat and shallow Nam Theun 2 Reservoir.
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Atmos. Meas. Tech., 11, 1599–1614, https://doi.org/10.5194/amt-11-1599-2018, https://doi.org/10.5194/amt-11-1599-2018, 2018
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Biogeosciences, 13, 3647–3663, https://doi.org/10.5194/bg-13-3647-2016, https://doi.org/10.5194/bg-13-3647-2016, 2016
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Methane (CH4) emissions from hydroelectric reservoirs could represent a significant fraction of global CH4 emissions from inland waters. The monitoring of methane emissions every 2 weeks at nine stations in a subtropical hydroelectric reservoir revealed that emissions could occasionally be 1 to 2 orders of magnitude higher than expected for these man-made ecosystems. Upstream of the water intake, emissions are enhanced by the water column mixing that upwells CH4-rich water to the surface.
C. Delon, E. Mougin, D. Serça, M. Grippa, P. Hiernaux, M. Diawara, C. Galy-Lacaux, and L. Kergoat
Biogeosciences, 12, 3253–3272, https://doi.org/10.5194/bg-12-3253-2015, https://doi.org/10.5194/bg-12-3253-2015, 2015
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C. Deshmukh, D. Serça, C. Delon, R. Tardif, M. Demarty, C. Jarnot, Y. Meyerfeld, V. Chanudet, P. Guédant, W. Rode, S. Descloux, and F. Guérin
Biogeosciences, 11, 4251–4269, https://doi.org/10.5194/bg-11-4251-2014, https://doi.org/10.5194/bg-11-4251-2014, 2014
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Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-11785-2014, https://doi.org/10.5194/bgd-11-11785-2014, 2014
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Atmos. Chem. Phys., 13, 10243–10269, https://doi.org/10.5194/acp-13-10243-2013, https://doi.org/10.5194/acp-13-10243-2013, 2013
R. Baghi, P. Durand, C. Jambert, C. Jarnot, C. Delon, D. Serça, N. Striebig, M. Ferlicoq, and P. Keravec
Atmos. Meas. Tech., 5, 3119–3132, https://doi.org/10.5194/amt-5-3119-2012, https://doi.org/10.5194/amt-5-3119-2012, 2012
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The exchange of CO2 between the sea and the atmosphere was studied in the Archipelago Sea, Baltic Sea, in 2017–2021, using an eddy covariance technique. The sea acted as a net source of CO2 with an average yearly emission of 27.1 gC m-2 yr-1, indicating that the marine ecosystem respired carbon that originated elsewhere. The yearly CO2 emission varied between 18.2–39.2 gC m-2 yr-1, mostly due to the yearly variation of ecosystem carbon uptake.
Ralf C. H. Aben, Daniël van de Craats, Jim Boonman, Stijn H. Peeters, Bart Vriend, Coline C. F. Boonman, Ype van der Velde, Gilles Erkens, and Merit van den Berg
Biogeosciences, 21, 4099–4118, https://doi.org/10.5194/bg-21-4099-2024, https://doi.org/10.5194/bg-21-4099-2024, 2024
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Drained peatlands cause high CO2 emissions. We assessed the effectiveness of subsurface water infiltration systems (WISs) in reducing CO2 emissions related to increases in water table depth (WTD) on 12 sites for up to 4 years. Results show WISs markedly reduced emissions by 2.1 t CO2-C ha-1 yr-1. The relationship between the amount of carbon above the WTD and CO2 emission was stronger than the relationship between WTD and emission. Long-term monitoring is crucial for accurate emission estimates.
Eva-Marie Metz, Sanam Noreen Vardag, Sourish Basu, Martin Jung, and André Butz
EGUsphere, https://doi.org/10.5194/egusphere-2024-1955, https://doi.org/10.5194/egusphere-2024-1955, 2024
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We estimate CO2 fluxes in semi-arid southern Africa from 2009 to 2018 based on satellite CO2 measurements and atmospheric inverse modelling. By selecting process-based vegetation models, which agree with the satellite CO2 fluxes, we find that soil respiration mainly drives the seasonality, whereas photosynthesis substantially influences the interannual variability. Our study emphasizes the need of better representing the response of semi-arid ecosystems to soil rewetting in vegetation models.
Ingeborg Bussmann, Eric P. Achterberg, Holger Brix, Nicolas Brüggemann, Götz Flöser, Claudia Schütze, and Philipp Fischer
Biogeosciences, 21, 3819–3838, https://doi.org/10.5194/bg-21-3819-2024, https://doi.org/10.5194/bg-21-3819-2024, 2024
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Methane (CH4) is an important greenhouse gas and contributes to climate warming. However, the input of CH4 from coastal areas to the atmosphere is not well defined. Dissolved and atmospheric CH4 was determined at high spatial resolution in or above the North Sea. The atmospheric CH4 concentration was mainly influenced by wind direction. With our detailed study on the spatial distribution of CH4 fluxes we were able to provide a detailed and more realistic estimation of coastal CH4 fluxes.
Olli-Pekka Tikkasalo, Olli Peltola, Pavel Alekseychik, Juha Heikkinen, Samuli Launiainen, Aleksi Lehtonen, Qian Li, Eduardo Martinez-García, Mikko Peltoniemi, Petri Salovaara, Ville Tuominen, and Raisa Mäkipää
EGUsphere, https://doi.org/10.5194/egusphere-2024-1994, https://doi.org/10.5194/egusphere-2024-1994, 2024
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The emissions of greenhouse gases (GHG) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were measured from a clearcut peatland forest site. The measurements covered the whole year of 2022 which was the second growing season after the clearcut. The site was a strong GHG source and the highest emissions came from CO2 followed by N2O and CH4. A statistical model that included information on different surfaces in the site was developed to unravel surface-type specific GHG fluxes.
Ruth Reef, Edoardo Daly, Tivanka Anandappa, Eboni-Jane Vienna-Hallam, Harriet Robertson, Matthew Peck, and Adrien Guyot
EGUsphere, https://doi.org/10.5194/egusphere-2024-2182, https://doi.org/10.5194/egusphere-2024-2182, 2024
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Studies show that saltmarshes excel at capturing carbon from the atmosphere. In this study, we measured CO2 flux in an Australian temperate saltmarsh on French Island. The temperate saltmarsh exhibited strong seasonality. During the warmer growing season, the saltmarsh absorbed on average 10.5 grams of CO2 from the atmosphere per m2 daily. Even in winter, when plants were dormant, it continued to be a CO2 sink, albeit smaller. Cool temperatures and high cloud cover inhibit carbon sequestration.
Niu Zhu, Jinniu Wang, Dongliang Luo, Xufeng Wang, Cheng Shen, and Ning Wu
Biogeosciences, 21, 3509–3522, https://doi.org/10.5194/bg-21-3509-2024, https://doi.org/10.5194/bg-21-3509-2024, 2024
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Our study delves into the vital role of subalpine forests in the Qinghai–Tibet Plateau as carbon sinks in the context of climate change. Utilizing advanced eddy covariance systems, we uncover their significant carbon sequestration potential, observing distinct seasonal patterns influenced by temperature, humidity, and radiation. Notably, these forests exhibit robust carbon absorption, with potential implications for global carbon balance.
Colette L. Kelly, Nicole M. Travis, Pascale Anabelle Baya, Claudia Frey, Xin Sun, Bess B. Ward, and Karen L. Casciotti
Biogeosciences, 21, 3215–3238, https://doi.org/10.5194/bg-21-3215-2024, https://doi.org/10.5194/bg-21-3215-2024, 2024
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Nitrous oxide, a potent greenhouse gas, accumulates in regions of the ocean that are low in dissolved oxygen. We used a novel combination of chemical tracers to determine how nitrous oxide is produced in one of these regions, the eastern tropical North Pacific Ocean. Our experiments showed that the two most important sources of nitrous oxide under low-oxygen conditions are denitrification, an anaerobic process, and a novel “hybrid” process performed by ammonia-oxidizing archaea.
Hella van Asperen, Thorsten Warneke, Alessandro Carioca de Araújo, Bruce Forsberg, Sávio José Filgueiras Ferreira, Thomas Röckmann, Carina van der Veen, Sipko Bulthuis, Leonardo Ramos de Oliveira, Thiago de Lima Xavier, Jailson da Mata, Marta de Oliveira Sá, Paulo Ricardo Teixeira, Julie Andrews de França e Silva, Susan Trumbore, and Justus Notholt
Biogeosciences, 21, 3183–3199, https://doi.org/10.5194/bg-21-3183-2024, https://doi.org/10.5194/bg-21-3183-2024, 2024
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Carbon monoxide (CO) is regarded as an important indirect greenhouse gas. Soils can emit and take up CO, but, until now, uncertainty remains as to which process dominates in tropical rainforests. We present the first soil CO flux measurements from a tropical rainforest. Based on our observations, we report that tropical rainforest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.
Sebastian F. A. Jordan, Stefan Schloemer, Martin Krüger, Tanja Heffner, Marcus A. Horn, and Martin Blumenberg
EGUsphere, https://doi.org/10.5194/egusphere-2024-1461, https://doi.org/10.5194/egusphere-2024-1461, 2024
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In a multilayered approach, we studied eight cut and buried abandoned oil wells in a peat rich area of Northern Germany for methane flux, soil gas composition, and isotopic signatures of soil methane and carbon dioxide. The detected methane emissions were of biogenic, peat origin and were not associated with the abandoned wells. Additional microbial analysis and methane oxidation rate measurements demonstrated a high methane-emission mitigation potential in the studied peat-soils.
Laura Thölix, Leif Backman, Minttu Havu, Esko Karvinen, Jesse Soininen, Justine Trémeau, Olli Nevalainen, Joyson Ahongshangbam, Leena Järvi, and Liisa Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2024-1453, https://doi.org/10.5194/egusphere-2024-1453, 2024
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Cities seek carbon neutrality and are interested in the sinks of urban vegetation. Measurements are difficult to do which leads to the need for modeling carbon cycle. In this study, we examined the performance of models in estimating carbon sequestration rates in lawns, park trees, and urban forests in Helsinki, Finland. We found that models simulated seasonal and annual variations well. Trees had larger carbon sequestration rates compared with lawns and irrigation often increased carbon sink.
Yélognissè Agbohessou, Claire Delon, Manuela Grippa, Eric Mougin, Daouda Ngom, Espoir Koudjo Gaglo, Ousmane Ndiaye, Paulo Salgado, and Olivier Roupsard
Biogeosciences, 21, 2811–2837, https://doi.org/10.5194/bg-21-2811-2024, https://doi.org/10.5194/bg-21-2811-2024, 2024
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Emissions of greenhouse gases in the Sahel are not well represented because they are considered weak compared to the rest of the world. However, natural areas in the Sahel emit carbon dioxide and nitrous oxides, which need to be assessed because of extended surfaces. We propose an assessment of such emissions in Sahelian silvopastoral systems and of how they are influenced by environmental characteristics. These results are essential to inform climate change strategies in the region.
Merit van den Berg, Thomas M. Gremmen, Renske J. E. Vroom, Jacobus van Huissteden, Jim Boonman, Corine J. A. van Huissteden, Ype van der Velde, Alfons J. P. Smolders, and Bas P. van de Riet
Biogeosciences, 21, 2669–2690, https://doi.org/10.5194/bg-21-2669-2024, https://doi.org/10.5194/bg-21-2669-2024, 2024
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Drained peatlands emit 3 % of the global greenhouse gas emissions. Paludiculture is a way to reduce CO2 emissions while at the same time generating an income for landowners. The side effect is the potentially high methane emissions. We found very high methane emissions for broadleaf cattail compared with narrowleaf cattail and water fern. The rewetting was, however, effective to stop CO2 emissions for all species. The highest potential to reduce greenhouse gas emissions had narrowleaf cattail.
Thea H. Heimdal, Galen A. McKinley, Adrienne J. Sutton, Amanda R. Fay, and Lucas Gloege
Biogeosciences, 21, 2159–2176, https://doi.org/10.5194/bg-21-2159-2024, https://doi.org/10.5194/bg-21-2159-2024, 2024
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Measurements of ocean carbon are limited in time and space. Machine learning algorithms are therefore used to reconstruct ocean carbon where observations do not exist. Improving these reconstructions is important in order to accurately estimate how much carbon the ocean absorbs from the atmosphere. In this study, we find that a small addition of observations from the Southern Ocean, obtained by autonomous sampling platforms, could significantly improve the reconstructions.
Gabrielle Emma Kleber, Leonard Magerl, Alexandra V. Turchyn, Mark Trimmer, Yizhu Zhu, and Andrew Hodson
EGUsphere, https://doi.org/10.5194/egusphere-2024-1273, https://doi.org/10.5194/egusphere-2024-1273, 2024
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Our research on Svalbard has uncovered that melting glaciers can release large amounts of methane, a potent greenhouse gas. By studying a glacier over two summers, we found that its river was highly concentrated in methane. This suggests that as the Arctic warms and glaciers melt, they could be a significant source of methane emissions. This is the first time such emissions have been measured on Svalbard, indicating a wider environmental concern as similar processes may occur across the Arctic.
Guilherme L. Torres Mendonça, Julia Pongratz, and Christian H. Reick
Biogeosciences, 21, 1923–1960, https://doi.org/10.5194/bg-21-1923-2024, https://doi.org/10.5194/bg-21-1923-2024, 2024
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We study the timescale dependence of airborne fraction and underlying feedbacks by a theory of the climate–carbon system. Using simulations we show the predictive power of this theory and find that (1) this fraction generally decreases for increasing timescales and (2) at all timescales the total feedback is negative and the model spread in a single feedback causes the spread in the airborne fraction. Our study indicates that those are properties of the system, independently of the scenario.
François Clayer, Jan Erik Thrane, Kuria Ndungu, Andrew King, Peter Dörsch, and Thomas Rohrlack
Biogeosciences, 21, 1903–1921, https://doi.org/10.5194/bg-21-1903-2024, https://doi.org/10.5194/bg-21-1903-2024, 2024
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Determination of dissolved greenhouse gas (GHG) in freshwater allows us to estimate GHG fluxes. Mercuric chloride (HgCl2) is used to preserve water samples prior to GHG analysis despite its environmental and health impacts and interferences with water chemistry in freshwater. Here, we tested the effects of HgCl2, two substitutes and storage time on GHG in water from two boreal lakes. Preservation with HgCl2 caused overestimation of CO2 concentration with consequences for GHG flux estimation.
Helena Rautakoski, Mika Korkiakoski, Jarmo Mäkelä, Markku Koskinen, Kari Minkkinen, Mika Aurela, Paavo Ojanen, and Annalea Lohila
Biogeosciences, 21, 1867–1886, https://doi.org/10.5194/bg-21-1867-2024, https://doi.org/10.5194/bg-21-1867-2024, 2024
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Current and future nitrous oxide (N2O) emissions are difficult to estimate due to their high variability in space and time. Several years of N2O fluxes from drained boreal peatland forest indicate high importance of summer precipitation, winter temperature, and snow conditions in controlling annual N2O emissions. The results indicate increasing year-to-year variation in N2O emissions in changing climate with more extreme seasonal weather conditions.
Matthias Koschorreck, Norbert Kamjunke, Uta Koedel, Michael Rode, Claudia Schuetze, and Ingeborg Bussmann
Biogeosciences, 21, 1613–1628, https://doi.org/10.5194/bg-21-1613-2024, https://doi.org/10.5194/bg-21-1613-2024, 2024
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We measured the emission of carbon dioxide (CO2) and methane (CH4) from different sites at the river Elbe in Germany over 3 days to find out what is more important for quantification: small-scale spatial variability or diurnal temporal variability. We found that CO2 emissions were very different between day and night, while CH4 emissions were more different between sites. Dried out river sediments contributed to CO2 emissions, while the side areas of the river were important CH4 sources.
Odysseas Sifounakis, Edwin Haas, Klaus Butterbach-Bahl, and Maria P. Papadopoulou
Biogeosciences, 21, 1563–1581, https://doi.org/10.5194/bg-21-1563-2024, https://doi.org/10.5194/bg-21-1563-2024, 2024
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We performed a full assessment of the carbon and nitrogen cycles of a cropland ecosystem. An uncertainty analysis and quantification of all carbon and nitrogen fluxes were deployed. The inventory simulations include greenhouse gas emissions of N2O, NH3 volatilization and NO3 leaching from arable land cultivation in Greece. The inventory also reports changes in soil organic carbon and nitrogen stocks in arable soils.
Sarah M. Ludwig, Luke Schiferl, Jacqueline Hung, Susan M. Natali, and Roisin Commane
Biogeosciences, 21, 1301–1321, https://doi.org/10.5194/bg-21-1301-2024, https://doi.org/10.5194/bg-21-1301-2024, 2024
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Landscapes are often assumed to be homogeneous when using eddy covariance fluxes, which can lead to biases when calculating carbon budgets. In this study we report eddy covariance carbon fluxes from heterogeneous tundra. We used the footprints of each flux observation to unmix the fluxes coming from components of the landscape. We identified and quantified hot spots of carbon emissions in the landscape. Accurately scaling with landscape heterogeneity yielded half as much regional carbon uptake.
Justine Trémeau, Beñat Olascoaga, Leif Backman, Esko Karvinen, Henriikka Vekuri, and Liisa Kulmala
Biogeosciences, 21, 949–972, https://doi.org/10.5194/bg-21-949-2024, https://doi.org/10.5194/bg-21-949-2024, 2024
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We studied urban lawns and meadows in the Helsinki metropolitan area, Finland. We found that meadows are more resistant to drought events but that they do not increase carbon sequestration compared with lawns. Moreover, the transformation from lawns to meadows did not demonstrate any negative climate effects in terms of greenhouse gas emissions. Even though social and economic aspects also steer urban development, these results can guide planning to consider carbon-smart options.
Guantao Chen, Edzo Veldkamp, Muhammad Damris, Bambang Irawan, Aiyen Tjoa, and Marife D. Corre
Biogeosciences, 21, 513–529, https://doi.org/10.5194/bg-21-513-2024, https://doi.org/10.5194/bg-21-513-2024, 2024
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We established an oil palm management experiment in a large-scale oil palm plantation in Jambi, Indonesia. We recorded oil palm fruit yield and measured soil CO2, N2O, and CH4 fluxes. After 4 years of treatment, compared with conventional fertilization with herbicide weeding, reduced fertilization with mechanical weeding did not reduce yield and soil greenhouse gas emissions, which highlights the legacy effects of over a decade of conventional management prior to the start of the experiment.
Elizabeth Gachibu Wangari, Ricky Mwangada Mwanake, Tobias Houska, David Kraus, Gretchen Maria Gettel, Ralf Kiese, Lutz Breuer, and Klaus Butterbach-Bahl
Biogeosciences, 20, 5029–5067, https://doi.org/10.5194/bg-20-5029-2023, https://doi.org/10.5194/bg-20-5029-2023, 2023
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Agricultural landscapes act as sinks or sources of the greenhouse gases (GHGs) CO2, CH4, or N2O. Various physicochemical and biological processes control the fluxes of these GHGs between ecosystems and the atmosphere. Therefore, fluxes depend on environmental conditions such as soil moisture, soil temperature, or soil parameters, which result in large spatial and temporal variations of GHG fluxes. Here, we describe an example of how this variation may be studied and analyzed.
Laurie C. Menviel, Paul Spence, Andrew E. Kiss, Matthew A. Chamberlain, Hakase Hayashida, Matthew H. England, and Darryn Waugh
Biogeosciences, 20, 4413–4431, https://doi.org/10.5194/bg-20-4413-2023, https://doi.org/10.5194/bg-20-4413-2023, 2023
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As the ocean absorbs 25% of the anthropogenic emissions of carbon, it is important to understand the impact of climate change on the flux of carbon between the ocean and the atmosphere. Here, we use a very high-resolution ocean, sea-ice, carbon cycle model to show that the capability of the Southern Ocean to uptake CO2 has decreased over the last 40 years due to a strengthening and poleward shift of the southern hemispheric westerlies. This trend is expected to continue over the coming century.
Petr Znachor, Jiří Nedoma, Vojtech Kolar, and Anna Matoušů
Biogeosciences, 20, 4273–4288, https://doi.org/10.5194/bg-20-4273-2023, https://doi.org/10.5194/bg-20-4273-2023, 2023
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We conducted intensive spatial sampling of the hypertrophic fishpond to better understand the spatial dynamics of methane fluxes and environmental heterogeneity in fishponds. The diffusive fluxes of methane accounted for only a minor fraction of the total fluxes and both varied pronouncedly within the pond and over the studied summer season. This could be explained only by the water depth. Wind substantially affected temperature, oxygen and chlorophyll a distribution in the pond.
Sofie Sjögersten, Martha Ledger, Matthias Siewert, Betsabé de la Barreda-Bautista, Andrew Sowter, David Gee, Giles Foody, and Doreen S. Boyd
Biogeosciences, 20, 4221–4239, https://doi.org/10.5194/bg-20-4221-2023, https://doi.org/10.5194/bg-20-4221-2023, 2023
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Permafrost thaw in Arctic regions is increasing methane emissions, but quantification is difficult given the large and remote areas impacted. We show that UAV data together with satellite data can be used to extrapolate emissions across the wider landscape as well as detect areas at risk of higher emissions. A transition of currently degrading areas to fen type vegetation can increase emission by several orders of magnitude, highlighting the importance of quantifying areas at risk.
Cole G. Brachmann, Tage Vowles, Riikka Rinnan, Mats P. Björkman, Anna Ekberg, and Robert G. Björk
Biogeosciences, 20, 4069–4086, https://doi.org/10.5194/bg-20-4069-2023, https://doi.org/10.5194/bg-20-4069-2023, 2023
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Herbivores change plant communities through grazing, altering the amount of CO2 and plant-specific chemicals (termed VOCs) emitted. We tested this effect by excluding herbivores and studying the CO2 and VOC emissions. Herbivores reduced CO2 emissions from a meadow community and altered VOC composition; however, community type had the strongest effect on the amount of CO2 and VOCs released. Herbivores can mediate greenhouse gas emissions, but the effect is marginal and community dependent.
Ole Lessmann, Jorge Encinas Fernández, Karla Martínez-Cruz, and Frank Peeters
Biogeosciences, 20, 4057–4068, https://doi.org/10.5194/bg-20-4057-2023, https://doi.org/10.5194/bg-20-4057-2023, 2023
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Based on a large dataset of seasonally resolved methane (CH4) pore water concentrations in a reservoir's sediment, we assess the significance of CH4 emissions due to reservoir flushing. In the studied reservoir, CH4 emissions caused by one flushing operation can represent 7 %–14 % of the annual CH4 emissions and depend on the timing of the flushing operation. In reservoirs with high sediment loadings, regular flushing may substantially contribute to the overall CH4 emissions.
Matti Räsänen, Risto Vesala, Petri Rönnholm, Laura Arppe, Petra Manninen, Markus Jylhä, Jouko Rikkinen, Petri Pellikka, and Janne Rinne
Biogeosciences, 20, 4029–4042, https://doi.org/10.5194/bg-20-4029-2023, https://doi.org/10.5194/bg-20-4029-2023, 2023
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Fungus-growing termites recycle large parts of dead plant material in African savannas and are significant sources of greenhouse gases. We measured CO2 and CH4 fluxes from their mounds and surrounding soils in open and closed habitats. The fluxes scale with mound volume. The results show that emissions from mounds of fungus-growing termites are more stable than those from other termites. The soil fluxes around the mound are affected by the termite colonies at up to 2 m distance from the mound.
Tim René de Groot, Anne Margriet Mol, Katherine Mesdag, Pierre Ramond, Rachel Ndhlovu, Julia Catherine Engelmann, Thomas Röckmann, and Helge Niemann
Biogeosciences, 20, 3857–3872, https://doi.org/10.5194/bg-20-3857-2023, https://doi.org/10.5194/bg-20-3857-2023, 2023
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This study investigates methane dynamics in the Wadden Sea. Our measurements revealed distinct variations triggered by seasonality and tidal forcing. The methane budget was higher in warmer seasons but surprisingly high in colder seasons. Methane dynamics were amplified during low tides, flushing the majority of methane into the North Sea or releasing it to the atmosphere. Methanotrophic activity was also elevated during low tide but mitigated only a small fraction of the methane efflux.
Frederic Thalasso, Brenda Riquelme, Andrés Gómez, Roy Mackenzie, Francisco Javier Aguirre, Jorge Hoyos-Santillan, Ricardo Rozzi, and Armando Sepulveda-Jauregui
Biogeosciences, 20, 3737–3749, https://doi.org/10.5194/bg-20-3737-2023, https://doi.org/10.5194/bg-20-3737-2023, 2023
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A robust skirt-chamber design to capture and quantify greenhouse gas emissions from peatlands is presented. Compared to standard methods, this design improves the spatial resolution of field studies in remote locations while minimizing intrusion.
Gesa Schulz, Tina Sanders, Yoana G. Voynova, Hermann W. Bange, and Kirstin Dähnke
Biogeosciences, 20, 3229–3247, https://doi.org/10.5194/bg-20-3229-2023, https://doi.org/10.5194/bg-20-3229-2023, 2023
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Nitrous oxide (N2O) is an important greenhouse gas. However, N2O emissions from estuaries underlie significant uncertainties due to limited data availability and high spatiotemporal variability. We found the Elbe Estuary (Germany) to be a year-round source of N2O, with the highest emissions in winter along with high nitrogen loads. However, in spring and summer, N2O emissions did not decrease alongside lower nitrogen loads because organic matter fueled in situ N2O production along the estuary.
Alex Mavrovic, Oliver Sonnentag, Juha Lemmetyinen, Jennifer L. Baltzer, Christophe Kinnard, and Alexandre Roy
Biogeosciences, 20, 2941–2970, https://doi.org/10.5194/bg-20-2941-2023, https://doi.org/10.5194/bg-20-2941-2023, 2023
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This review supports the integration of microwave spaceborne information into carbon cycle science for Arctic–boreal regions. The microwave data record spans multiple decades with frequent global observations of soil moisture and temperature, surface freeze–thaw cycles, vegetation water storage, snowpack properties, and land cover. This record holds substantial unexploited potential to better understand carbon cycle processes.
Zoé Rehder, Thomas Kleinen, Lars Kutzbach, Victor Stepanenko, Moritz Langer, and Victor Brovkin
Biogeosciences, 20, 2837–2855, https://doi.org/10.5194/bg-20-2837-2023, https://doi.org/10.5194/bg-20-2837-2023, 2023
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We use a new model to investigate how methane emissions from Arctic ponds change with warming. We find that emissions increase substantially. Under annual temperatures 5 °C above present temperatures, pond methane emissions are more than 3 times higher than now. Most of this increase is caused by an increase in plant productivity as plants provide the substrate microbes used to produce methane. We conclude that vegetation changes need to be included in predictions of pond methane emissions.
Julian Koch, Lars Elsgaard, Mogens H. Greve, Steen Gyldenkærne, Cecilie Hermansen, Gregor Levin, Shubiao Wu, and Simon Stisen
Biogeosciences, 20, 2387–2403, https://doi.org/10.5194/bg-20-2387-2023, https://doi.org/10.5194/bg-20-2387-2023, 2023
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Utilizing peatlands for agriculture leads to large emissions of greenhouse gases worldwide. The emissions are triggered by lowering the water table, which is a necessary step in order to make peatlands arable. Many countries aim at reducing their emissions by restoring peatlands, which can be achieved by stopping agricultural activities and thereby raising the water table. We estimate a total emission of 2.6 Mt CO2-eq for organic-rich peatlands in Denmark and a potential reduction of 77 %.
Mélissa Laurent, Matthias Fuchs, Tanja Herbst, Alexandra Runge, Susanne Liebner, and Claire C. Treat
Biogeosciences, 20, 2049–2064, https://doi.org/10.5194/bg-20-2049-2023, https://doi.org/10.5194/bg-20-2049-2023, 2023
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In this study we investigated the effect of different parameters (temperature, landscape position) on the production of greenhouse gases during a 1-year permafrost thaw experiment. For very similar carbon and nitrogen contents, our results show a strong heterogeneity in CH4 production, as well as in microbial abundance. According to our study, these differences are mainly due to the landscape position and the hydrological conditions established as a result of the topography.
Michael Moubarak, Seeta Sistla, Stefano Potter, Susan M. Natali, and Brendan M. Rogers
Biogeosciences, 20, 1537–1557, https://doi.org/10.5194/bg-20-1537-2023, https://doi.org/10.5194/bg-20-1537-2023, 2023
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Tundra wildfires are increasing in frequency and severity with climate change. We show using a combination of field measurements and computational modeling that tundra wildfires result in a positive feedback to climate change by emitting significant amounts of long-lived greenhouse gasses. With these effects, attention to tundra fires is necessary for mitigating climate change.
Cited articles
Abril, G., Guerin, F., Richard, S., Delmas, R., Galy-Lacaux, C., Gosse, P.,
Tremblay, A., Varfalvy, L., Dos Santos, M. A., and Matvienko, B.: Carbon
dioxide and methane emissions and the carbon budget of a 10-year old
tropical reservoir (Petit Saut, French Guiana), Global Biogeochem. Cy., 19, GB4007,
https://doi.org/10.1029/2005gb002457, 2005.
Abril, G., Commarieu, M. V., and Guérin, F.: Enhanced methane oxidation
in an estuarine turbidity maximum, Limnol. Oceanogr., 52, 470–475,
2007.
Barros, N., Cole, J. J., Tranvik, L. J., Prairie, Y. T., Bastviken, D.,
Huszar, V. L. M., del Giorgio, P., and Roland, F.: Carbon emission from
hydroelectric reservoirs linked to reservoir age and latitude, Nat. Geosci., 4, 593–596, 2011.
Borges, A. V., Delille, B., Schiettecatte, L. S., Gazeau, F., Abril, G., and
Frankignoulle, M.: Gas transfer velocities of CO2 in three European
estuaries (Randers Fjord, Scheldt, and Thames), Limnol. Oceanogr.,
49, 1630–1641, 2004.
Chanudet, V., Descloux, S., Harby, A., Sundt, H., Hansen, B. H., Brakstad,
O., Serca, D., and Guerin, F.: Gross CO2 and CH4 emissions from the Nam Ngum
and Nam Leuk sub-tropical reservoirs in Lao PDR, Sci. Total Environ., 409, 5382–5391, https://doi.org/10.1016/j.scitotenv.2011.09.018, 2011.
Chanudet, V., Fabre, V., and van der Kaaij, T.: Application of a
three-dimensional hydrodynamic model to the Nam Theun 2 Reservoir (Lao PDR),
J. Great Lakes Res., 38, 260–269,
https://doi.org/10.1016/j.jglr.2012.01.008, 2012.
Chanudet, V., Guédant, P., Rode, W., Godon, A., Guérin, F.,
Serça, D., Deshmukh, C., and Descloux, S.: Evolution of the
physico-chemical water quality in the Nam Theun 2 Reservoir and downstream
rivers for the first 5 years after impoundment, Hydroécol. Appl., in press, https://doi.org/10.1051/hydro/2015001, 2015.
Chen, H., Wu, Y., Yuan, X., Gao, Y., Wu, N., and Zhu, D.: Methane emissions
from newly created marshes in the drawdown area of the Three Gorges
Reservoir, J. Geophys. Res., 114, D18301, https://doi.org/10.1029/2009JD012410, 2009.
Chen, H., Yuan, X., Chen, Z., Wu, Y., Liu, X., Zhu, D., Wu, N., Zhu, Q. A.,
Peng, C., and Li, W.: Methane emissions from the surface of the Three Gorges
Reservoir, J. Geophys. Res., 116, D21306, https://doi.org/10.1029/2011jd016244, 2011.
Descloux, S., Guedant, P., Phommachanh, D., and Luthi, R.: Main features of
the Nam Theun 2 hydroelectric project (Lao PDR) and the associated
environmental monitoring programmes, Hydroécol. Appl., in press,
https://doi.org/10.1051/hydro/20140052014, 2014.
Descloux, S., Chanudet, V., Taquet, B., Rode, W., Guédant, P.,
Serça, D., Deshmukh, C., and Guerin, F.: Efficiency of the Nam Theun 2
hydraulic structures on water aeration and methane degassing, Hydroécol.
Appl., in press, https://doi.org/10.1051/hydro/2015002, 2015.
Deshmukh, C., Serça, D., Delon, C., Tardif, R., Demarty, M., Jarnot, C.,
Meyerfeld, Y., Chanudet, V., Guédant, P., Rode, W., Descloux, S., and Guérin, F.:
Physical controls on CH4 emissions from a newly flooded subtropical freshwater
hydroelectric reservoir: Nam Theun 2, Biogeosciences, 11, 4251–4269, https://doi.org/10.5194/bg-11-4251-2014, 2014.
Dumestre, J. F., Guezennec, J., Galy-Lacaux, C., Delmas, R., Richard, S.,
and Labroue, L.: Influence of Light Intensity on Methanotrophic Bacterial
Activity in Petit Saut Reservoir, French Guiana, Appl. Environ. Microbiol.,
65, 534–539, 1999.
Galy-Lacaux, C., Delmas, R., Jambert, C., Dumestre, J. F., Labroue, L.,
Richard, S., and Gosse, P.: Gaseous emissions and oxygen consumption in
hydroelectric dams: A case study in French Guyana, Global Biogeochem. Cy.,
11, 471–483, 1997.
Guérin, F. and Abril, G.: Significance of pelagic aerobic methane
oxidation in the methane and carbon budget of a tropical reservoir, J. Geophys. Res.-Biogeo., 112, G03006, https://doi.org/10.1029/2006jg000393,
2007.
Guérin, F., Abril, G., Richard, S., Burban, B., Reynouard, C., Seyler,
P., and Delmas, R.: Methane and carbon dioxide emissions from tropical
reservoirs: Significance of downstream rivers, Geophys. Res. Lett.,
33, L21407, https://doi.org/10.1029/2006gl027929, 2006.
Guérin, F., Abril, G., Serca, D., Delon, C., Richard, S., Delmas, R.,
Tremblay, A., and Varfalvy, L.: Gas transfer velocities of CO2 and CH4 in a
tropical reservoir and its river downstream, J. Marine Syst., 66,
161–172, https://doi.org/10.1016/j.jmarsys.2006.03.019, 2007.
Guérin, F., Deshmukh, C., Labat, D., Pighini, S., Vongkhamsao, A., Guédant, P., Rode, W.,
Godon, A., Chanudet, V., Descloux, S., and Serça, D.: Effect of sporadic destratification,
seasonal overturn and artificial mixing on CH4 emissions at the surface of a subtropical hydroelectric
reservoir (Nam Theun 2 Reservoir, Lao PDR), Biogeosciences Discuss., under review, 12, 11349–11385, https://doi.org/10.5194/bgd-12-11349-2015,
2015.
Kemenes, A., Forsberg, B. R., and Melack, J. M.: Methane release below a
tropical hydroelectric dam, Geophys. Res. Lett., 34, L12809
https://doi.org/10.1029/2007gl029479, 2007.
Li, S. and Zhang, Q.: Carbon emission from global hydroelectric reservoirs
revisited, Environ. Sci. Pollut. Res., 21, 13636–13641,
https://doi.org/10.1007/s11356-014-3165-4, 2014.
Li, Z., Zhang, Z., Xiao, Y., Guo, J., Wu, S., and Liu, J.: Spatio-temporal
variations of carbon dioxide and its gross emission regulated by artificial
operation in a typical hydropower reservoir in China, Environ.
Monit. Assess., 186, 3023–3039, https://doi.org/10.1007/s10661-013-3598-0, 2014.
Lima, I., Ramos, F., Bambace, L., and Rosa, R.: Methane Emissions from Large
Dams as Renewable Energy Resources: A Developing Nation Perspective,
Mitigation and Adaptation Strategies for Global Change, 13, 193–206, 2008.
Liss, P. S. and Slater, P. G.: Flux of Gases across the Air-Sea Interface,
Nature, 247, 181–184, https://doi.org/10.1038/247181a0, 1974.
Maeck, A., DelSontro, T., McGinnis, D. F., Fischer, H., Flury, S., Schmidt,
M., Fietzek, P., and Lorke, A.: Sediment Trapping by Dams Creates Methane
Emission Hot Spots, Environ. Sci. Technol., 47, 8130–8137,
https://doi.org/10.1021/es4003907, 2013.
Murase, J. and Sugimoto, A.: Inhibitory effect of light on methane
oxidation in the pelagic water column of a mesotrophic lake (Lake Biwa,
Japan), Limnol. Oceanogr., 50, 1339–1343, 2005.
Narvenkar, G., Naqvi, S. W. A., Kurian, S., Shenoy, D. M., Pratihary, A. K.,
Naik, H., Patil, S., Sarkar, A., and Gauns, M.: Dissolved methane in Indian
freshwater reservoirs, Environ. Monit. Assess., 185,
6989–6999, https://doi.org/10.1007/s10661-013-3079-5, 2013.
Némery, J., Gratiot, N., Doan, P. T. K., Duvert, C., Alvarado-Villanueva, R., and
Duwig, C.: Carbon, nitrogen, phosphorus, and sediment sources and retention in a small
eutrophic tropical reservoir, Aquat. Sci., 1–19, https://doi.org/10.1007/s00027-015-0416-5, 2015.
NTPC: Environmental Assessment and Management Plan – Nam Theun 2
Hydroelectric Project. Nam Theun 2 Power Company, NTPC (Nam Theun 2 Power
Company), Vientiane, 212, 2005.
Teodoru, C. R., Bastien, J., Bonneville, M.-C., del Giorgio, P. A., Demarty,
M., Garneau, M., Hélie, J.-F., Pelletier, L., Prairie, Y. T., Roulet, N.
T., Strachan, I. B., and Tremblay, A.: The net carbon footprint of a newly
created boreal hydroelectric reservoir, Global Biogeochem. Cy., 26, GB2016,
https://doi.org/10.1029/2011gb004187, 2012.
Venkiteswaran, J. J. and Schiff, S. L.: Methane oxidation: isotopic
enrichment factors in freshwater boreal reservoirs, Appl. Geochem.,
20, 683–690, 2005.
Wanninkhof, R.: Relationship between wind-speed and gas-exchange over the
ocean, J. Geophys. Res.-Oceans, 97, 7373–7382, 1992.
Yamamoto, S., Alcauskas, J. B., and Crozier, T. E.: Solubility of methane in
distilled water and seawater, J. Chem. Eng. Data, 21,
78–80, https://doi.org/10.1021/je60068a029, 1976.
Short summary
Methane (CH4) emissions from hydroelectric reservoirs could represent a significant fraction of global CH4 emissions from inland waters and wetlands. The first quantification of emissions downstream of a subtropical reservoir shows that they contribute only 10 to 30 % of total CH4 emissions from the reservoir. This surprisingly low contribution is due to the seasonal reservoir overturn and the effect of the turbine on re-aerating the reservoir water column.
Methane (CH4) emissions from hydroelectric reservoirs could represent a significant fraction of...
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