Articles | Volume 17, issue 23
https://doi.org/10.5194/bg-17-6207-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-17-6207-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Dec 2020
Research article |
| 09 Dec 2020
| 09 Dec 2020
Seasonality, drivers, and isotopic composition of soil CO2 fluxes from tropical forests of the Congo Basin
Simon Baumgartner
CORRESPONDING AUTHOR
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
Matti Barthel
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Travis William Drake
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Marijn Bauters
Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
Department of Environment, Ghent University, Ghent, Belgium
Isaac Ahanamungu Makelele
Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
Département de Biologie, Université Officielle de Bukavu, Bukavu, Democratic Republic of the Congo
John Kalume Mugula
Département de Biologie, Université Officielle de Bukavu, Bukavu, Democratic Republic of the Congo
Laura Summerauer
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Nora Gallarotti
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Landry Cizungu Ntaboba
Département d'Agronomie, Université Catholique de Bukavu, Bukavu, Democratic Republic of the Congo
Kristof Van Oost
Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
Pascal Boeckx
Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
Sebastian Doetterl
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Roland Anton Werner
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
Johan Six
Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
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Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
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Pengzhi Zhao, Daniel Joseph Fallu, Sara Cucchiaro, Paolo Tarolli, Clive Waddington, David Cockcroft, Lisa Snape, Andreas Lang, Sebastian Doetterl, Antony G. Brown, and Kristof Van Oost
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Caroline C. Clason, Will H. Blake, Nick Selmes, Alex Taylor, Pascal Boeckx, Jessica Kitch, Stephanie C. Mills, Giovanni Baccolo, and Geoffrey E. Millward
The Cryosphere, 15, 5151–5168, https://doi.org/10.5194/tc-15-5151-2021, https://doi.org/10.5194/tc-15-5151-2021, 2021
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Our paper presents results of sample collection and subsequent geochemical analyses from the glaciated Isfallsglaciären catchment in Arctic Sweden. The data suggest that material found on the surface of glaciers,
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Philipp Baumann, Juhwan Lee, Emmanuel Frossard, Laurie Paule Schönholzer, Lucien Diby, Valérie Kouamé Hgaza, Delwende Innocent Kiba, Andrew Sila, Keith Sheperd, and Johan Six
SOIL, 7, 717–731, https://doi.org/10.5194/soil-7-717-2021, https://doi.org/10.5194/soil-7-717-2021, 2021
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This work delivers openly accessible and validated calibrations for diagnosing 26 soil properties based on mid-infrared spectroscopy. These were developed for four regions in Burkina Faso and Côte d'Ivoire, including 80 fields of smallholder farmers. The models can help to site-specifically and cost-efficiently monitor soil quality and fertility constraints to ameliorate soils and yields of yam or other staple crops in the four regions between the humid forest and the northern Guinean savanna.
Laura Summerauer, Philipp Baumann, Leonardo Ramirez-Lopez, Matti Barthel, Marijn Bauters, Benjamin Bukombe, Mario Reichenbach, Pascal Boeckx, Elizabeth Kearsley, Kristof Van Oost, Bernard Vanlauwe, Dieudonné Chiragaga, Aimé Bisimwa Heri-Kazi, Pieter Moonen, Andrew Sila, Keith Shepherd, Basile Bazirake Mujinya, Eric Van Ranst, Geert Baert, Sebastian Doetterl, and Johan Six
SOIL, 7, 693–715, https://doi.org/10.5194/soil-7-693-2021, https://doi.org/10.5194/soil-7-693-2021, 2021
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We present a soil mid-infrared library with over 1800 samples from central Africa in order to facilitate soil analyses of this highly understudied yet critical area. Together with an existing continental library, we demonstrate a regional analysis and geographical extrapolation to predict total carbon and nitrogen. Our results show accurate predictions and highlight the value that the data contribute to existing libraries. Our library is openly available for public use and for expansion.
Benjamin Bukombe, Peter Fiener, Alison M. Hoyt, Laurent K. Kidinda, and Sebastian Doetterl
SOIL, 7, 639–659, https://doi.org/10.5194/soil-7-639-2021, https://doi.org/10.5194/soil-7-639-2021, 2021
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Through a laboratory incubation experiment, we investigated the spatial patterns of specific maximum heterotrophic respiration in tropical African mountain forest soils developed from contrasting parent material along slope gradients. We found distinct differences in soil respiration between soil depths and geochemical regions related to soil fertility and the chemistry of the soil solution. The topographic origin of our samples was not a major determinant of the observed rates of respiration.
Heleen Deroo, Masuda Akter, Samuel Bodé, Orly Mendoza, Haichao Li, Pascal Boeckx, and Steven Sleutel
Biogeosciences, 18, 5035–5051, https://doi.org/10.5194/bg-18-5035-2021, https://doi.org/10.5194/bg-18-5035-2021, 2021
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We assessed if and how incorporation of exogenous organic carbon (OC) such as straw could affect decomposition of native soil organic carbon (SOC) under different irrigation regimes. Addition of exogenous OC promoted dissolution of native SOC, partly because of increased Fe reduction, leading to more net release of Fe-bound SOC. Yet, there was no proportionate priming of SOC-derived DOC mineralisation. Water-saving irrigation can retard both priming of SOC dissolution and mineralisation.
Lander Van Tricht, Philippe Huybrechts, Jonas Van Breedam, Alexander Vanhulle, Kristof Van Oost, and Harry Zekollari
The Cryosphere, 15, 4445–4464, https://doi.org/10.5194/tc-15-4445-2021, https://doi.org/10.5194/tc-15-4445-2021, 2021
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We conducted innovative research on the use of drones to determine the surface mass balance (SMB) of two glaciers. Considering appropriate spatial scales, we succeeded in determining the SMB in the ablation area with large accuracy. Consequently, we are convinced that our method and the use of drones to monitor the mass balance of a glacier’s ablation area can be an add-on to stake measurements in order to obtain a broader picture of the heterogeneity of the SMB of glaciers.
Sebastian Doetterl, Rodrigue K. Asifiwe, Geert Baert, Fernando Bamba, Marijn Bauters, Pascal Boeckx, Benjamin Bukombe, Georg Cadisch, Matthew Cooper, Landry N. Cizungu, Alison Hoyt, Clovis Kabaseke, Karsten Kalbitz, Laurent Kidinda, Annina Maier, Moritz Mainka, Julia Mayrock, Daniel Muhindo, Basile B. Mujinya, Serge M. Mukotanyi, Leon Nabahungu, Mario Reichenbach, Boris Rewald, Johan Six, Anna Stegmann, Laura Summerauer, Robin Unseld, Bernard Vanlauwe, Kristof Van Oost, Kris Verheyen, Cordula Vogel, Florian Wilken, and Peter Fiener
Earth Syst. Sci. Data, 13, 4133–4153, https://doi.org/10.5194/essd-13-4133-2021, https://doi.org/10.5194/essd-13-4133-2021, 2021
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The African Tropics are hotspots of modern-day land use change and are of great relevance for the global carbon cycle. Here, we present data collected as part of the DFG-funded project TropSOC along topographic, land use, and geochemical gradients in the eastern Congo Basin and the Albertine Rift. Our database contains spatial and temporal data on soil, vegetation, environmental properties, and land management collected from 136 pristine tropical forest and cropland plots between 2017 and 2020.
Philipp Baumann, Anatol Helfenstein, Andreas Gubler, Armin Keller, Reto Giulio Meuli, Daniel Wächter, Juhwan Lee, Raphael Viscarra Rossel, and Johan Six
SOIL, 7, 525–546, https://doi.org/10.5194/soil-7-525-2021, https://doi.org/10.5194/soil-7-525-2021, 2021
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We developed the Swiss mid-infrared spectral library and a statistical model collection across 4374 soil samples with reference measurements of 16 properties. Our library incorporates soil from 1094 grid locations and 71 long-term monitoring sites. This work confirms once again that nationwide spectral libraries with diverse soils can reliably feed information to a fast chemical diagnosis. Our data-driven reduction of the library has the potential to accurately monitor carbon at the plot scale.
Mario Reichenbach, Peter Fiener, Gina Garland, Marco Griepentrog, Johan Six, and Sebastian Doetterl
SOIL, 7, 453–475, https://doi.org/10.5194/soil-7-453-2021, https://doi.org/10.5194/soil-7-453-2021, 2021
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of soil organic carbon stocks differ between soils developed from geochemically contrasting parent material due to differences in the abundance of organo-mineral complexes, the presence/absence of chemical stabilization mechanisms of carbon with minerals and the presence of fossil organic carbon from sedimentary rocks. Physical stabilization mechanisms by aggregation provide additional protection of soil carbon.
Joseph Tamale, Roman Hüppi, Marco Griepentrog, Laban Frank Turyagyenda, Matti Barthel, Sebastian Doetterl, Peter Fiener, and Oliver van Straaten
SOIL, 7, 433–451, https://doi.org/10.5194/soil-7-433-2021, https://doi.org/10.5194/soil-7-433-2021, 2021
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Soil greenhouse gas (GHG) fluxes were measured monthly from nitrogen (N), phosphorous (P), N and P, and control plots of the first nutrient manipulation experiment located in an African pristine tropical forest using static chambers. The results suggest (1) contrasting soil GHG responses to nutrient addition, hence highlighting the complexity of the tropical forests, and (2) that the feedback of tropical forests to the global soil GHG budget could be altered by changes in N and P availability.
Florian Wilken, Peter Fiener, Michael Ketterer, Katrin Meusburger, Daniel Iragi Muhindo, Kristof van Oost, and Sebastian Doetterl
SOIL, 7, 399–414, https://doi.org/10.5194/soil-7-399-2021, https://doi.org/10.5194/soil-7-399-2021, 2021
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This study demonstrates the usability of fallout radionuclides 239Pu and 240Pu as a tool to assess soil degradation processes in tropical Africa, which is particularly valuable in regions with limited infrastructure and challenging monitoring conditions for landscape-scale soil degradation monitoring. The study shows no indication of soil redistribution in forest sites but substantial soil redistribution in cropland (sedimentation >40 cm in 55 years) with high variability.
Sophie F. von Fromm, Alison M. Hoyt, Markus Lange, Gifty E. Acquah, Ermias Aynekulu, Asmeret Asefaw Berhe, Stephan M. Haefele, Steve P. McGrath, Keith D. Shepherd, Andrew M. Sila, Johan Six, Erick K. Towett, Susan E. Trumbore, Tor-G. Vågen, Elvis Weullow, Leigh A. Winowiecki, and Sebastian Doetterl
SOIL, 7, 305–332, https://doi.org/10.5194/soil-7-305-2021, https://doi.org/10.5194/soil-7-305-2021, 2021
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We investigated various soil and climate properties that influence soil organic carbon (SOC) concentrations in sub-Saharan Africa. Our findings indicate that climate and geochemistry are equally important for explaining SOC variations. The key SOC-controlling factors are broadly similar to those for temperate regions, despite differences in soil development history between the two regions.
Anatol Helfenstein, Philipp Baumann, Raphael Viscarra Rossel, Andreas Gubler, Stefan Oechslin, and Johan Six
SOIL, 7, 193–215, https://doi.org/10.5194/soil-7-193-2021, https://doi.org/10.5194/soil-7-193-2021, 2021
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In this study, we show that a soil spectral library (SSL) can be used to predict soil carbon at new and very different locations. The importance of this finding is that it requires less time-consuming lab work than calibrating a new model for every local application, while still remaining similar to or more accurate than local models. Furthermore, we show that this method even works for predicting (drained) peat soils, using a SSL with mostly mineral soils containing much less soil carbon.
Simon Baumgartner, Marijn Bauters, Matti Barthel, Travis W. Drake, Landry C. Ntaboba, Basile M. Bazirake, Johan Six, Pascal Boeckx, and Kristof Van Oost
SOIL, 7, 83–94, https://doi.org/10.5194/soil-7-83-2021, https://doi.org/10.5194/soil-7-83-2021, 2021
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We compared stable isotope signatures of soil profiles in different forest ecosystems within the Congo Basin to assess ecosystem-level differences in N cycling, and we examined the local effect of topography on the isotopic signature of soil N. Soil δ15N profiles indicated that the N cycling in in the montane forest is more closed, whereas the lowland forest and Miombo woodland experienced a more open N cycle. Topography only alters soil δ15N values in forests with high erosional forces.
Paula Alejandra Lamprea Pineda, Marijn Bauters, Hans Verbeeck, Selene Baez, Matti Barthel, Samuel Bodé, and Pascal Boeckx
Biogeosciences, 18, 413–421, https://doi.org/10.5194/bg-18-413-2021, https://doi.org/10.5194/bg-18-413-2021, 2021
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Tropical forest soils are an important source and sink of greenhouse gases (GHGs) with tropical montane forests having been poorly studied. In this pilot study, we explored soil fluxes of CO2, CH4, and N2O in an Ecuadorian neotropical montane forest, where a net consumption of N2O at higher altitudes was observed. Our results highlight the importance of short-term variations in N2O and provide arguments and insights for future, more detailed studies on GHG fluxes from montane forest soils.
Laurent K. Kidinda, Folasade K. Olagoke, Cordula Vogel, Karsten Kalbitz, and Sebastian Doetterl
SOIL Discuss., https://doi.org/10.5194/soil-2020-80, https://doi.org/10.5194/soil-2020-80, 2020
Preprint withdrawn
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In deeply weathered tropical rainforest soils of Africa, we found that patterns of microbial processes differ between soils developed from geochemically contrasting parent materials due to differences in resource availability. Across investigated geochemical regions and soil depths, soil microbes were P-limited rather than N-limited. Topsoil microbes were more C-limited than their subsoil counterparts but inversely P-limited.
Zhengang Wang, Jianxiu Qiu, and Kristof Van Oost
Geosci. Model Dev., 13, 4977–4992, https://doi.org/10.5194/gmd-13-4977-2020, https://doi.org/10.5194/gmd-13-4977-2020, 2020
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This study developed a spatially distributed carbon cycling model applicable in an eroding landscape. It includes all three carbon isotopes so that it is able to represent the carbon isotopic compositions. The model is able to represent the observations that eroding area is enriched in 13C and depleted of 14C compared to depositional area. Our simulations show that the spatial variability of carbon isotopic properties in an eroding landscape is mainly caused by the soil redistribution.
Hannes P. T. De Deurwaerder, Marco D. Visser, Matteo Detto, Pascal Boeckx, Félicien Meunier, Kathrin Kuehnhammer, Ruth-Kristina Magh, John D. Marshall, Lixin Wang, Liangju Zhao, and Hans Verbeeck
Biogeosciences, 17, 4853–4870, https://doi.org/10.5194/bg-17-4853-2020, https://doi.org/10.5194/bg-17-4853-2020, 2020
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The depths at which plants take up water is challenging to observe directly. To do so, scientists have relied on measuring the isotopic composition of xylem water as this provides information on the water’s source. Our work shows that this isotopic composition changes throughout the day, which complicates the interpretation of the water’s source and has been currently overlooked. We build a model to help understand the origin of these composition changes and their consequences for science.
Long Ho, Ruben Jerves-Cobo, Matti Barthel, Johan Six, Samuel Bode, Pascal Boeckx, and Peter Goethals
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-311, https://doi.org/10.5194/bg-2020-311, 2020
Revised manuscript not accepted
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Rivers are being polluted by human activities, especially in urban areas. We studied the greenhouse gas (GHG) emissions from an urban river system. The results showed a clear trend between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality worsened, its contribution to global warming can go up by 10 times. Urban rivers emitted 4-times more than of the amount of GHGs compared to rivers in natural sites.
Marijn Van de Broek, Shiva Ghiasi, Charlotte Decock, Andreas Hund, Samuel Abiven, Cordula Friedli, Roland A. Werner, and Johan Six
Biogeosciences, 17, 2971–2986, https://doi.org/10.5194/bg-17-2971-2020, https://doi.org/10.5194/bg-17-2971-2020, 2020
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Four wheat cultivars were labeled with 13CO2 to quantify the effect of rooting depth and root biomass on the belowground transfer of organic carbon. We found no clear relation between the time since cultivar development and the amount of carbon inputs to the soil. Therefore, the hypothesis that wheat cultivars with a larger root biomass and deeper roots promote carbon stabilization was rejected. The amount of root biomass that will be stabilized in the soil on the long term is, however, unknown.
Stephen J. Harris, Jesper Liisberg, Longlong Xia, Jing Wei, Kerstin Zeyer, Longfei Yu, Matti Barthel, Benjamin Wolf, Bryce F. J. Kelly, Dioni I. Cendón, Thomas Blunier, Johan Six, and Joachim Mohn
Atmos. Meas. Tech., 13, 2797–2831, https://doi.org/10.5194/amt-13-2797-2020, https://doi.org/10.5194/amt-13-2797-2020, 2020
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The latest commercial laser spectrometers have the potential to revolutionize N2O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data.
Marco Pfeiffer, José Padarian, Rodrigo Osorio, Nelson Bustamante, Guillermo Federico Olmedo, Mario Guevara, Felipe Aburto, Francisco Albornoz, Monica Antilén, Elías Araya, Eduardo Arellano, Maialen Barret, Juan Barrera, Pascal Boeckx, Margarita Briceño, Sally Bunning, Lea Cabrol, Manuel Casanova, Pablo Cornejo, Fabio Corradini, Gustavo Curaqueo, Sebastian Doetterl, Paola Duran, Mauricio Escudey, Angelina Espinoza, Samuel Francke, Juan Pablo Fuentes, Marcel Fuentes, Gonzalo Gajardo, Rafael García, Audrey Gallaud, Mauricio Galleguillos, Andrés Gomez, Marcela Hidalgo, Jorge Ivelic-Sáez, Lwando Mashalaba, Francisco Matus, Francisco Meza, Maria de la Luz Mora, Jorge Mora, Cristina Muñoz, Pablo Norambuena, Carolina Olivera, Carlos Ovalle, Marcelo Panichini, Aníbal Pauchard, Jorge F. Pérez-Quezada, Sergio Radic, José Ramirez, Nicolás Riveras, Germán Ruiz, Osvaldo Salazar, Iván Salgado, Oscar Seguel, Maria Sepúlveda, Carlos Sierra, Yasna Tapia, Francisco Tapia, Balfredo Toledo, José Miguel Torrico, Susana Valle, Ronald Vargas, Michael Wolff, and Erick Zagal
Earth Syst. Sci. Data, 12, 457–468, https://doi.org/10.5194/essd-12-457-2020, https://doi.org/10.5194/essd-12-457-2020, 2020
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The CHLSOC database is the biggest soil organic carbon (SOC) database that has been compiled for Chile yet, comprising 13 612 data points. This database is the product of the compilation of numerous sources including unpublished and difficult-to-access data, allowing us to fill numerous spatial gaps where no SOC estimates were publicly available before. The values of SOC compiled in CHLSOC have a wide range, reflecting the variety of ecosystems that exists in Chile.
Corey R. Lawrence, Jeffrey Beem-Miller, Alison M. Hoyt, Grey Monroe, Carlos A. Sierra, Shane Stoner, Katherine Heckman, Joseph C. Blankinship, Susan E. Crow, Gavin McNicol, Susan Trumbore, Paul A. Levine, Olga Vindušková, Katherine Todd-Brown, Craig Rasmussen, Caitlin E. Hicks Pries, Christina Schädel, Karis McFarlane, Sebastian Doetterl, Christine Hatté, Yujie He, Claire Treat, Jennifer W. Harden, Margaret S. Torn, Cristian Estop-Aragonés, Asmeret Asefaw Berhe, Marco Keiluweit, Ágatha Della Rosa Kuhnen, Erika Marin-Spiotta, Alain F. Plante, Aaron Thompson, Zheng Shi, Joshua P. Schimel, Lydia J. S. Vaughn, Sophie F. von Fromm, and Rota Wagai
Earth Syst. Sci. Data, 12, 61–76, https://doi.org/10.5194/essd-12-61-2020, https://doi.org/10.5194/essd-12-61-2020, 2020
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The International Soil Radiocarbon Database (ISRaD) is an an open-source archive of soil data focused on datasets including radiocarbon measurements. ISRaD includes data from bulk or
whole soils, distinct soil carbon pools isolated in the laboratory by a variety of soil fractionation methods, samples of soil gas or water collected interstitially from within an intact soil profile, CO2 gas isolated from laboratory soil incubations, and fluxes collected in situ from a soil surface.
Samuel Bouchoms, Zhengang Wang, Veerle Vanacker, and Kristof Van Oost
SOIL, 5, 367–382, https://doi.org/10.5194/soil-5-367-2019, https://doi.org/10.5194/soil-5-367-2019, 2019
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Soil erosion has detrimental effects on soil fertility which can reduce carbon inputs coming from crops to soils. Our study integrated this effect into a model linking soil organic carbon (SOC) dynamics to erosion and crop productivity. When compared to observations, the inclusion of productivity improved SOC loss predictions. Over centuries, ignoring crop productivity evolution in models could result in underestimating SOC loss and overestimating C exchanged with the atmosphere.
François Clapuyt, Veerle Vanacker, Marcus Christl, Kristof Van Oost, and Fritz Schlunegger
Solid Earth, 10, 1489–1503, https://doi.org/10.5194/se-10-1489-2019, https://doi.org/10.5194/se-10-1489-2019, 2019
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Using state-of-the-art geomorphic techniques, we quantified a 2-order of magnitude discrepancy between annual, decadal, and millennial sediment fluxes of a landslide-affected mountainous river catchment in the Swiss Alps. Our results illustrate that the impact of a single sediment pulse is strongly attenuated at larger spatial and temporal scales by sediment transport. The accumulation of multiple sediment pulses has rather a measurable impact on the regional pattern of sediment fluxes.
He Zhang, Emilien Aldana-Jague, François Clapuyt, Florian Wilken, Veerle Vanacker, and Kristof Van Oost
Earth Surf. Dynam., 7, 807–827, https://doi.org/10.5194/esurf-7-807-2019, https://doi.org/10.5194/esurf-7-807-2019, 2019
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We evaluated the performance of a drone system to reconstruct 3-D topography. We used a direct georeferencing method to make the pictures have precise coordinates, which also improves the survey efficiency. With both consumer-grade and professional-grade camera and drone setups, we obtained centimetric accuracy, which provides a flexible application in topography remote sensing using drones.
Karl Voglmeier, Johan Six, Markus Jocher, and Christof Ammann
Biogeosciences, 16, 1685–1703, https://doi.org/10.5194/bg-16-1685-2019, https://doi.org/10.5194/bg-16-1685-2019, 2019
Tino Colombi, Florian Walder, Lucie Büchi, Marlies Sommer, Kexing Liu, Johan Six, Marcel G. A. van der Heijden, Raphaël Charles, and Thomas Keller
SOIL, 5, 91–105, https://doi.org/10.5194/soil-5-91-2019, https://doi.org/10.5194/soil-5-91-2019, 2019
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The role of soil aeration in carbon sequestration in arable soils has only been explored little, especially at the farm level. The current study, which was conducted on 30 fields that belong to individual farms, reveals a positive relationship between soil gas transport capability and soil organic carbon content. We therefore conclude that soil aeration needs to be accounted for when developing strategies for carbon sequestration in arable soil.
Elizabeth Verhoeven, Matti Barthel, Longfei Yu, Luisella Celi, Daniel Said-Pullicino, Steven Sleutel, Dominika Lewicka-Szczebak, Johan Six, and Charlotte Decock
Biogeosciences, 16, 383–408, https://doi.org/10.5194/bg-16-383-2019, https://doi.org/10.5194/bg-16-383-2019, 2019
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This study utilized state-of-the-art measurements of nitrogen isotopes to evaluate nitrogen cycling and to assess the biological sources of the potent greenhouse gas, N2O, in response to water-saving practices in rice systems. Water-saving practices did emit more N2O, and high N2O production had a lower 15N isotope signature. Modeling and visual interpretation indicate that these emissions mostly came from denitrification or nitrifier denitrification, controlled upstream by nitrification rates.
Victoria Naipal, Philippe Ciais, Yilong Wang, Ronny Lauerwald, Bertrand Guenet, and Kristof Van Oost
Biogeosciences, 15, 4459–4480, https://doi.org/10.5194/bg-15-4459-2018, https://doi.org/10.5194/bg-15-4459-2018, 2018
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We seek to better understand the links between soil erosion by rainfall and the global carbon (C) cycle by coupling a soil erosion model to the C cycle of a land surface model. With this modeling approach we evaluate the effects of soil removal on soil C stocks in the presence of climate change and land use change. We find that accelerated soil erosion leads to a potential SOC removal flux of 74 ±18 Pg of C globally over the period AD 1850–2005, with significant impacts on the land C balance.
Natalie Orlowski, Lutz Breuer, Nicolas Angeli, Pascal Boeckx, Christophe Brumbt, Craig S. Cook, Maren Dubbert, Jens Dyckmans, Barbora Gallagher, Benjamin Gralher, Barbara Herbstritt, Pedro Hervé-Fernández, Christophe Hissler, Paul Koeniger, Arnaud Legout, Chandelle Joan Macdonald, Carlos Oyarzún, Regine Redelstein, Christof Seidler, Rolf Siegwolf, Christine Stumpp, Simon Thomsen, Markus Weiler, Christiane Werner, and Jeffrey J. McDonnell
Hydrol. Earth Syst. Sci., 22, 3619–3637, https://doi.org/10.5194/hess-22-3619-2018, https://doi.org/10.5194/hess-22-3619-2018, 2018
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To extract water from soils for isotopic analysis, cryogenic water extraction is the most widely used removal technique. This work presents results from a worldwide laboratory intercomparison test of cryogenic extraction systems. Our results showed large differences in retrieved isotopic signatures among participating laboratories linked to interactions between soil type and properties, system setup, extraction efficiency, extraction system leaks, and each lab’s internal accuracy.
François Clapuyt, Veerle Vanacker, Fritz Schlunegger, and Kristof Van Oost
Earth Surf. Dynam., 5, 791–806, https://doi.org/10.5194/esurf-5-791-2017, https://doi.org/10.5194/esurf-5-791-2017, 2017
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This work aims at understanding the behaviour of an earth flow located in the Swiss Alps by reconstructing very accurately its topography over a 2-year period. Aerial photos taken from a drone, which are then processed using a computer vision algorithm, were used to derive the topographic datasets. Combination and careful interpretation of high-resolution topographic analyses reveal the internal mechanisms of the earthflow and its complex rotational structure, which is evolving over time.
Marijn Bauters, Hans Verbeeck, Miro Demol, Stijn Bruneel, Cys Taveirne, Dries Van der Heyden, Landry Cizungu, and Pascal Boeckx
Biogeosciences, 14, 5313–5321, https://doi.org/10.5194/bg-14-5313-2017, https://doi.org/10.5194/bg-14-5313-2017, 2017
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We assessed community-weighted functional canopy traits and indicative δ15N shifts along two new altitudinal transects in the tropical forest biome of both South America and Africa. We found that the functional forest composition and δ15N response along both transects was parallel, with a species shift towards more nitrogen-conservative species at higher elevations.
Dane Dickinson, Samuel Bodé, and Pascal Boeckx
Atmos. Meas. Tech., 10, 4507–4519, https://doi.org/10.5194/amt-10-4507-2017, https://doi.org/10.5194/amt-10-4507-2017, 2017
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Cavity ring-down spectroscopy (CRDS) is an increasingly popular technology for isotope analysis of trace gases. However, most commercial CRDS instruments are designed for continuous gas sampling and cannot reliably measure small discrete samples. We present a novel technical adaptation that allows routine analysis of 50 mL syringed samples on an isotopic-CO2 CRDS unit. Our method offers excellent accuracy and precision, fast sample throughput, and is easily implemented in other CRDS instruments.
Florian Wilken, Michael Sommer, Kristof Van Oost, Oliver Bens, and Peter Fiener
SOIL, 3, 83–94, https://doi.org/10.5194/soil-3-83-2017, https://doi.org/10.5194/soil-3-83-2017, 2017
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Model-based analyses of the effect of soil erosion on carbon (C) dynamics are associated with large uncertainties partly resulting from oversimplifications of erosion processes. This study evaluates the need for process-oriented modelling to analyse erosion-induced C fluxes in different catchments. The results underline the importance of a detailed representation of tillage and water erosion processes. For water erosion, grain-size-specific transport is essential to simulate lateral C fluxes.
Gerard Govers, Roel Merckx, Bas van Wesemael, and Kristof Van Oost
SOIL, 3, 45–59, https://doi.org/10.5194/soil-3-45-2017, https://doi.org/10.5194/soil-3-45-2017, 2017
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We discuss pathways towards better soil protection in the 21st century. The efficacy of soil conservation technology is not a fundamental barrier for a more sustainable soil management. However, soil conservation is generally not directly beneficial to the farmer. We believe that the solution of this conundrum is a rapid, smart intensification of agriculture in the Global South. This will reduce the financial burden and will, at the same time, allow more effective conservation.
Florian Wilken, Peter Fiener, and Kristof Van Oost
Earth Surf. Dynam., 5, 113–124, https://doi.org/10.5194/esurf-5-113-2017, https://doi.org/10.5194/esurf-5-113-2017, 2017
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This study presents a model that accounts for preferential erosion and transport of sediment and soil organic carbon in agricultural landscapes. We applied the model to a small catchment in Belgium for a period of 100 years. After a thorough model evaluation, these simulations shows that sediment and carbon export are highly episodic and that the temporal variability is largely influenced by selective erosion and deposition.
Lien De Wispelaere, Samuel Bodé, Pedro Hervé-Fernández, Andreas Hemp, Dirk Verschuren, and Pascal Boeckx
Biogeosciences, 14, 73–88, https://doi.org/10.5194/bg-14-73-2017, https://doi.org/10.5194/bg-14-73-2017, 2017
Louise C. Andresen, Anna-Karin Björsne, Samuel Bodé, Leif Klemedtsson, Pascal Boeckx, and Tobias Rütting
SOIL, 2, 433–442, https://doi.org/10.5194/soil-2-433-2016, https://doi.org/10.5194/soil-2-433-2016, 2016
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In soil the constant transport of nitrogen (N) containing compounds from soil organic matter and debris out into the soil water, is controlled by soil microbes and enzymes that literally cut down polymers (such as proteins) into single amino acids (AA), hereafter microbes consume AAs and excrete ammonium back to the soil. We developed a method for analysing N turnover and flow of organic N, based on parallel 15N tracing experiments. The numerical model gives robust and simultaneous quantification.
Jianlin Zhao, Kristof Van Oost, Longqian Chen, and Gerard Govers
Biogeosciences, 13, 4735–4750, https://doi.org/10.5194/bg-13-4735-2016, https://doi.org/10.5194/bg-13-4735-2016, 2016
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We used a novel approach to reassess erosion rates on the CLP. We found that both current average topsoil erosion rates and the maximum magnitude of the erosion-induced carbon sink are overestimated on the CLP. Although average topsoil losses on the CLP are still high, a major increase in agricultural productivity occurred since 1980. Hence, erosion is currently not a direct threat to agricultural productivity on the CLP but the long-term effects of erosion on soil quality remain important.
Victoria Naipal, Christian Reick, Kristof Van Oost, Thomas Hoffmann, and Julia Pongratz
Earth Surf. Dynam., 4, 407–423, https://doi.org/10.5194/esurf-4-407-2016, https://doi.org/10.5194/esurf-4-407-2016, 2016
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We present a new large-scale coarse-resolution sediment budget model that is compatible with Earth system models and simulates sediment dynamics in floodplains and on hillslopes. We applied this model on the Rhine catchment for the last millennium, and found that the model reproduces the spatial distribution of sediment storage and the scaling relationships as found in observations. We also identified that land use change explains most of the temporal variability in sediment storage.
R. Hüppi, R. Felber, A. Neftel, J. Six, and J. Leifeld
SOIL, 1, 707–717, https://doi.org/10.5194/soil-1-707-2015, https://doi.org/10.5194/soil-1-707-2015, 2015
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Biochar is considered an opportunity to tackle major environmental issues in agriculture. Adding pyrolised organic residues to soil may sequester carbon, increase yields and reduce nitrous oxide emissions from soil. It is unknown, whether the latter is induced by changes in soil pH. We show that biochar application substantially reduces nitrous oxide emissions from a temperate maize cropping system. However, the reduction was only achieved with biochar but not with liming.
C. Decock, J. Lee, M. Necpalova, E. I. P. Pereira, D. M. Tendall, and J. Six
SOIL, 1, 687–694, https://doi.org/10.5194/soil-1-687-2015, https://doi.org/10.5194/soil-1-687-2015, 2015
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Further progress in understanding and mitigating N2O emissions from soil lies within transdisciplinary research that reaches across spatial scales and takes an ambitious look into the future.
V. Naipal, C. Reick, J. Pongratz, and K. Van Oost
Geosci. Model Dev., 8, 2893–2913, https://doi.org/10.5194/gmd-8-2893-2015, https://doi.org/10.5194/gmd-8-2893-2015, 2015
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We adjusted the topographical and rainfall erosivity factors that are the triggers of erosion in the Revised Universal Soil Loss Equation (RUSLE) model to make the model better applicable at coarse resolution on a global scale. The adjusted RUSLE model compares much better to current high resolution estimates of soil erosion in the USA and Europe. It therefore provides a basis for estimating past and future global impacts of soil erosion on climate with the use of Earth system models.
M. S. Torn, A. Chabbi, P. Crill, P. J. Hanson, I. A. Janssens, Y. Luo, C. H. Pries, C. Rumpel, M. W. I. Schmidt, J. Six, M. Schrumpf, and B. Zhu
SOIL, 1, 575–582, https://doi.org/10.5194/soil-1-575-2015, https://doi.org/10.5194/soil-1-575-2015, 2015
F. Wiaux, M. Vanclooster, and K. Van Oost
Biogeosciences, 12, 4637–4649, https://doi.org/10.5194/bg-12-4637-2015, https://doi.org/10.5194/bg-12-4637-2015, 2015
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In this study, we highlight the role of soil physical conditions and gas transfer mechanisms and dynamics in the decomposition and storage of soil organic carbon in subsoil layers. To illustrate it, we measured the time series of soil temperature, moisture and CO2 concentration and calculated CO2 fluxes along 1 m depth soil profiles during 6 months throughout two contrasted soil profiles along a hillslope in the central loess belt of Belgium.
B. Wolf, L. Merbold, C. Decock, B. Tuzson, E. Harris, J. Six, L. Emmenegger, and J. Mohn
Biogeosciences, 12, 2517–2531, https://doi.org/10.5194/bg-12-2517-2015, https://doi.org/10.5194/bg-12-2517-2015, 2015
L. C. Andresen, S. Bode, A. Tietema, P. Boeckx, and T. Rütting
SOIL, 1, 341–349, https://doi.org/10.5194/soil-1-341-2015, https://doi.org/10.5194/soil-1-341-2015, 2015
J. W. van Groenigen, D. Huygens, P. Boeckx, Th. W. Kuyper, I. M. Lubbers, T. Rütting, and P. M. Groffman
SOIL, 1, 235–256, https://doi.org/10.5194/soil-1-235-2015, https://doi.org/10.5194/soil-1-235-2015, 2015
S. Doetterl, J.-T. Cornelis, J. Six, S. Bodé, S. Opfergelt, P. Boeckx, and K. Van Oost
Biogeosciences, 12, 1357–1371, https://doi.org/10.5194/bg-12-1357-2015, https://doi.org/10.5194/bg-12-1357-2015, 2015
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We link the mineralogy of soils affected by erosion and deposition to the distribution of soil carbon fractions, their turnover and microbial activity. We show that the weathering status of soils and their history are controlling the stabilization of carbon with minerals. After burial, aggregated C is preserved more efficiently while non-aggregated C can be released and younger C re-sequestered more easily. Weathering changes the effectiveness of stabilization mechanism limiting this C sink.
E. C. Brevik, A. Cerdà, J. Mataix-Solera, L. Pereg, J. N. Quinton, J. Six, and K. Van Oost
SOIL, 1, 117–129, https://doi.org/10.5194/soil-1-117-2015, https://doi.org/10.5194/soil-1-117-2015, 2015
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This paper provides a brief accounting of some of the many ways that the study of soils can be interdisciplinary, therefore giving examples of the types of papers we hope to see submitted to SOIL.
D. Xue, P. Boeckx, and Z. Wang
Biogeosciences, 11, 5957–5967, https://doi.org/10.5194/bg-11-5957-2014, https://doi.org/10.5194/bg-11-5957-2014, 2014
Z. Wang, K. Van Oost, A. Lang, T. Quine, W. Clymans, R. Merckx, B. Notebaert, and G. Govers
Biogeosciences, 11, 873–883, https://doi.org/10.5194/bg-11-873-2014, https://doi.org/10.5194/bg-11-873-2014, 2014
T. Hoffmann, S. M. Mudd, K. van Oost, G. Verstraeten, G. Erkens, A. Lang, H. Middelkoop, J. Boyle, J. O. Kaplan, J. Willenbring, and R. Aalto
Earth Surf. Dynam., 1, 45–52, https://doi.org/10.5194/esurf-1-45-2013, https://doi.org/10.5194/esurf-1-45-2013, 2013
R. M. Rees, J. Augustin, G. Alberti, B. C. Ball, P. Boeckx, A. Cantarel, S. Castaldi, N. Chirinda, B. Chojnicki, M. Giebels, H. Gordon, B. Grosz, L. Horvath, R. Juszczak, Å. Kasimir Klemedtsson, L. Klemedtsson, S. Medinets, A. Machon, F. Mapanda, J. Nyamangara, J. E. Olesen, D. S. Reay, L. Sanchez, A. Sanz Cobena, K. A. Smith, A. Sowerby, M. Sommer, J. F. Soussana, M. Stenberg, C. F. E. Topp, O. van Cleemput, A. Vallejo, C. A. Watson, and M. Wuta
Biogeosciences, 10, 2671–2682, https://doi.org/10.5194/bg-10-2671-2013, https://doi.org/10.5194/bg-10-2671-2013, 2013
N. Gharahi Ghehi, C. Werner, K. Hufkens, R. Kiese, E. Van Ranst, D. Nsabimana, G. Wallin, L. Klemedtsson, K. Butterbach-Bahl, and P. Boeckx
Biogeosciences Discuss., https://doi.org/10.5194/bgd-10-1483-2013, https://doi.org/10.5194/bgd-10-1483-2013, 2013
Revised manuscript not accepted
Related subject area
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Assessing improvements in global ocean pCO2 machine learning reconstructions with Southern Ocean autonomous sampling
Timescale dependence of airborne fraction and underlying climate–carbon-cycle feedbacks for weak perturbations in CMIP5 models
Technical note: Preventing CO2 overestimation from mercuric or copper(II) chloride preservation of dissolved greenhouse gases in freshwater samples
Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data
Diurnal versus spatial variability of greenhouse gas emissions from an anthropogenically modified lowland river in Germany
Regional assessment and uncertainty analysis of carbon and nitrogen balances at cropland scale using the ecosystem model LandscapeDNDC
Resolving heterogeneous fluxes from tundra halves the growing season carbon budget
Lawns and meadows in urban green space – a comparison from perspectives of greenhouse gases, drought resilience and plant functional types
Large contribution of soil N2O emission to the global warming potential of a large-scale oil palm plantation despite changing from conventional to reduced management practices
Influence of wind strength and direction on diffusive methane fluxes and atmospheric methane concentrations above the North Sea
Identifying landscape hot and cold spots of soil greenhouse gas fluxes by combining field measurements and remote sensing data
The emission of CO from tropical rain forest soils
Using Eddy Covariance Observations to Determine the Carbon Sequestration Characteristics of Subalpine Forests in the Qinghai-Tibet Plateau
Isotopomer labeling and oxygen dependence of hybrid nitrous oxide production
Enhanced Southern Ocean CO2 outgassing as a result of stronger and poleward shifted southern hemispheric westerlies
Spatial and temporal variability of methane emissions and environmental conditions in a hyper-eutrophic fishpond
Optical and radar Earth observation data for upscaling methane emissions linked to permafrost degradation in sub-Arctic peatlands in northern Sweden
Herbivore–shrub interactions influence ecosystem respiration and biogenic volatile organic compound composition in the subarctic
Methane emissions due to reservoir flushing: a significant emission pathway?
Carbon dioxide and methane fluxes from mounds of African fungus-growing termites
Diel and seasonal methane dynamics in the shallow and turbulent Wadden Sea
Technical note: Skirt chamber – an open dynamic method for the rapid and minimally intrusive measurement of greenhouse gas emissions from peatlands
Seasonal variability of nitrous oxide concentrations and emissions in a temperate estuary
Reviews and syntheses: Recent advances in microwave remote sensing in support of terrestrial carbon cycle science in Arctic–boreal regions
Simulated methane emissions from Arctic ponds are highly sensitive to warming
Water-table-driven greenhouse gas emission estimates guide peatland restoration at national scale
Relationships between greenhouse gas production and landscape position during short-term permafrost thaw under anaerobic conditions in the Lena Delta
Carbon emissions and radiative forcings from tundra wildfires in the Yukon–Kuskokwim River Delta, Alaska
Carbon monoxide (CO) cycling in the Fram Strait, Arctic Ocean
Post-flooding disturbance recovery promotes carbon capture in riparian zones
Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape
Carbon emission and export from the Ket River, western Siberia
Evaluation of wetland CH4 in the Joint UK Land Environment Simulator (JULES) land surface model using satellite observations
Greenhouse gas fluxes in mangrove forest soil in an Amazon estuary
Temporal patterns and drivers of CO2 emission from dry sediments in a groyne field of a large river
Effects of water table level and nitrogen deposition on methane and nitrous oxide emissions in an alpine peatland
Highest methane concentrations in an Arctic river linked to local terrestrial inputs
Seasonal study of the small-scale variability in dissolved methane in the western Kiel Bight (Baltic Sea) during the European heatwave in 2018
Trace gas fluxes from tidal salt marsh soils: implications for carbon–sulfur biogeochemistry
Spatial and temporal variation in δ13C values of methane emitted from a hemiboreal mire: methanogenesis, methanotrophy, and hysteresis
Intercomparison of methods to estimate gross primary production based on CO2 and COS flux measurements
Lateral carbon export has low impact on the net ecosystem carbon balance of a polygonal tundra catchment
The effect of static chamber base on N2O flux in drip irrigation
Controls on autotrophic and heterotrophic respiration in an ombrotrophic bog
Episodic N2O emissions following tillage of a legume–grass cover crop mixture
Variation in CO2 and CH4 fluxes among land cover types in heterogeneous Arctic tundra in northeastern Siberia
Response of vegetation and carbon fluxes to brown lemming herbivory in northern Alaska
Sources of nitrous oxide and the fate of mineral nitrogen in subarctic permafrost peat soils
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.
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.
Ingeborg Bussmann, Eric P. Achterberg, Holger Brix, Nicolas Brüggemann, Götz Flöser, Claudia Schütze, and Philipp Fischer
EGUsphere, https://doi.org/10.5194/egusphere-2023-3018, https://doi.org/10.5194/egusphere-2023-3018, 2024
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Methane (CH4) is an important greenhouse gas and contributes to climate warming. The input of CH4 from coastal areas to the atmosphere however 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.
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.
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
EGUsphere, https://doi.org/10.5194/egusphere-2023-2746, https://doi.org/10.5194/egusphere-2023-2746, 2023
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Carbon monoxide (CO) is considered an important indirect greenhouse gas. Soils can emit as well as take up CO but, until now, uncertainty remains which process dominates in tropical rain forests. We present the first soil CO flux measurements from a tropical rain forest. Based on our observations, we report that tropical rain forest 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.
Niu Zhu, Jinniu Wang, Dongliang Luo, Xufeng Wang, Cheng Shen, and Ning Wu
EGUsphere, https://doi.org/10.5194/egusphere-2023-2669, https://doi.org/10.5194/egusphere-2023-2669, 2023
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Our study delves into the vital role of subalpine forest 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 forest exhibit robust carbon absorption, with potential implications for global carbon balance.
Colette L. Kelly, Nicole M. Travis, Pascale A. Baya, Claudia Frey, Xin Sun, Bess B. Ward, and Karen L. Casciotti
EGUsphere, https://doi.org/10.5194/egusphere-2023-2642, https://doi.org/10.5194/egusphere-2023-2642, 2023
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We investigated the origins of nitrous oxide, a potent greenhouse gas, in low oxygen ocean regions. Our findings shed light on the microbial processes behind nitrous oxide production, including “hybrid” nitrous oxide generation by ammonia-oxidizing archaea, one of the most abundant organisms in the ocean. We also observed a strong link between nitrous oxide production and oxygen levels. These results set up potential feedbacks between oxygen depletion and greenhouse gas cycling in the oceans.
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.
Hanna I. Campen, Damian L. Arévalo-Martínez, and Hermann W. Bange
Biogeosciences, 20, 1371–1379, https://doi.org/10.5194/bg-20-1371-2023, https://doi.org/10.5194/bg-20-1371-2023, 2023
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Carbon monoxide (CO) is a climate-relevant trace gas emitted from the ocean. However, oceanic CO cycling is understudied. Results from incubation experiments conducted in the Fram Strait (Arctic Ocean) indicated that (i) pH did not affect CO cycling and (ii) enhanced CO production and consumption were positively correlated with coloured dissolved organic matter and nitrate concentrations. This suggests microbial CO uptake to be the driving factor for CO cycling in the Arctic Ocean.
Yihong Zhu, Ruihua Liu, Huai Zhang, Shaoda Liu, Zhengfeng Zhang, Fei-Hai Yu, and Timothy G. Gregoire
Biogeosciences, 20, 1357–1370, https://doi.org/10.5194/bg-20-1357-2023, https://doi.org/10.5194/bg-20-1357-2023, 2023
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With global warming, the risk of flooding is rising, but the response of the carbon cycle of aquatic and associated riparian systems
to flooding is still unclear. Based on the data collected in the Lijiang, we found that flooding would lead to significant carbon emissions of fluvial areas and riparian areas during flooding, but carbon capture may happen after flooding. In the riparian areas, the surviving vegetation, especially clonal plants, played a vital role in this transformation.
Lauri Heiskanen, Juha-Pekka Tuovinen, Henriikka Vekuri, Aleksi Räsänen, Tarmo Virtanen, Sari Juutinen, Annalea Lohila, Juha Mikola, and Mika Aurela
Biogeosciences, 20, 545–572, https://doi.org/10.5194/bg-20-545-2023, https://doi.org/10.5194/bg-20-545-2023, 2023
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We measured and modelled the CO2 and CH4 fluxes of the terrestrial and aquatic ecosystems of the subarctic landscape for 2 years. The landscape was an annual CO2 sink and a CH4 source. The forest had the largest contribution to the landscape-level CO2 sink and the peatland to the CH4 emissions. The lakes released 24 % of the annual net C uptake of the landscape back to the atmosphere. The C fluxes were affected most by the rainy peak growing season of 2017 and the drought event in July 2018.
Artem G. Lim, Ivan V. Krickov, Sergey N. Vorobyev, Mikhail A. Korets, Sergey Kopysov, Liudmila S. Shirokova, Jan Karlsson, and Oleg S. Pokrovsky
Biogeosciences, 19, 5859–5877, https://doi.org/10.5194/bg-19-5859-2022, https://doi.org/10.5194/bg-19-5859-2022, 2022
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In order to quantify C transport and emission and main environmental factors controlling the C cycle in Siberian rivers, we investigated the largest tributary of the Ob River, the Ket River basin, by measuring spatial and seasonal variations in carbon CO2 and CH4 concentrations and emissions together with hydrochemical analyses. The obtained results are useful for large-scale modeling of C emission and export fluxes from permafrost-free boreal rivers of an underrepresented region of the world.
Robert J. Parker, Chris Wilson, Edward Comyn-Platt, Garry Hayman, Toby R. Marthews, A. Anthony Bloom, Mark F. Lunt, Nicola Gedney, Simon J. Dadson, Joe McNorton, Neil Humpage, Hartmut Boesch, Martyn P. Chipperfield, Paul I. Palmer, and Dai Yamazaki
Biogeosciences, 19, 5779–5805, https://doi.org/10.5194/bg-19-5779-2022, https://doi.org/10.5194/bg-19-5779-2022, 2022
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Wetlands are the largest natural source of methane, one of the most important climate gases. The JULES land surface model simulates these emissions. We use satellite data to evaluate how well JULES reproduces the methane seasonal cycle over different tropical wetlands. It performs well for most regions; however, it struggles for some African wetlands influenced heavily by river flooding. We explain the reasons for these deficiencies and highlight how future development will improve these areas.
Saúl Edgardo Martínez Castellón, José Henrique Cattanio, José Francisco Berrêdo, Marcelo Rollnic, Maria de Lourdes Ruivo, and Carlos Noriega
Biogeosciences, 19, 5483–5497, https://doi.org/10.5194/bg-19-5483-2022, https://doi.org/10.5194/bg-19-5483-2022, 2022
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We seek to understand the influence of climatic seasonality and microtopography on CO2 and CH4 fluxes in an Amazonian mangrove. Topography and seasonality had a contrasting influence when comparing the two gas fluxes: CO2 fluxes were greater in high topography in the dry period, and CH4 fluxes were greater in the rainy season in low topography. Only CO2 fluxes were correlated with soil organic matter, the proportion of carbon and nitrogen, and redox potential.
Matthias Koschorreck, Klaus Holger Knorr, and Lelaina Teichert
Biogeosciences, 19, 5221–5236, https://doi.org/10.5194/bg-19-5221-2022, https://doi.org/10.5194/bg-19-5221-2022, 2022
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At low water levels, parts of the bottom of rivers fall dry. These beaches or mudflats emit the greenhouse gas carbon dioxide (CO2) to the atmosphere. We found that those emissions are caused by microbial reactions in the sediment and that they change with time. Emissions were influenced by many factors like temperature, water level, rain, plants, and light.
Wantong Zhang, Zhengyi Hu, Joachim Audet, Thomas A. Davidson, Enze Kang, Xiaoming Kang, Yong Li, Xiaodong Zhang, and Jinzhi Wang
Biogeosciences, 19, 5187–5197, https://doi.org/10.5194/bg-19-5187-2022, https://doi.org/10.5194/bg-19-5187-2022, 2022
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This work focused on the CH4 and N2O emissions from alpine peatlands in response to the interactive effects of altered water table levels and increased nitrogen deposition. Across the 2-year mesocosm experiment, nitrogen deposition showed nonlinear effects on CH4 emissions and linear effects on N2O emissions, and these N effects were associated with the water table levels. Our results imply the future scenario of strengthened CH4 and N2O emissions from an alpine peatland.
Karel Castro-Morales, Anna Canning, Sophie Arzberger, Will A. Overholt, Kirsten Küsel, Olaf Kolle, Mathias Göckede, Nikita Zimov, and Arne Körtzinger
Biogeosciences, 19, 5059–5077, https://doi.org/10.5194/bg-19-5059-2022, https://doi.org/10.5194/bg-19-5059-2022, 2022
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Permafrost thaw releases methane that can be emitted into the atmosphere or transported by Arctic rivers. Methane measurements are lacking in large Arctic river regions. In the Kolyma River (northeast Siberia), we measured dissolved methane to map its distribution with great spatial detail. The river’s edge and river junctions had the highest methane concentrations compared to other river areas. Microbial communities in the river showed that the river’s methane likely is from the adjacent land.
Sonja Gindorf, Hermann W. Bange, Dennis Booge, and Annette Kock
Biogeosciences, 19, 4993–5006, https://doi.org/10.5194/bg-19-4993-2022, https://doi.org/10.5194/bg-19-4993-2022, 2022
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Methane is a climate-relevant greenhouse gas which is emitted to the atmosphere from coastal areas such as the Baltic Sea. We measured the methane concentration in the water column of the western Kiel Bight. Methane concentrations were higher in September than in June. We found no relationship between the 2018 European heatwave and methane concentrations. Our results show that the methane distribution in the water column is strongly affected by temporal and spatial variabilities.
Margaret Capooci and Rodrigo Vargas
Biogeosciences, 19, 4655–4670, https://doi.org/10.5194/bg-19-4655-2022, https://doi.org/10.5194/bg-19-4655-2022, 2022
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Tidal salt marsh soil emits greenhouse gases, as well as sulfur-based gases, which play roles in global climate but are not well studied as they are difficult to measure. Traditional methods of measuring these gases worked relatively well for carbon dioxide, but less so for methane, nitrous oxide, carbon disulfide, and dimethylsulfide. High variability of trace gases complicates the ability to accurately calculate gas budgets and new approaches are needed for monitoring protocols.
Janne Rinne, Patryk Łakomiec, Patrik Vestin, Joel D. White, Per Weslien, Julia Kelly, Natascha Kljun, Lena Ström, and Leif Klemedtsson
Biogeosciences, 19, 4331–4349, https://doi.org/10.5194/bg-19-4331-2022, https://doi.org/10.5194/bg-19-4331-2022, 2022
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The study uses the stable isotope 13C of carbon in methane to investigate the origins of spatial and temporal variation in methane emitted by a temperate wetland ecosystem. The results indicate that methane production is more important for spatial variation than methane consumption by micro-organisms. Temporal variation on a seasonal timescale is most likely affected by more than one driver simultaneously.
Kukka-Maaria Kohonen, Roderick Dewar, Gianluca Tramontana, Aleksanteri Mauranen, Pasi Kolari, Linda M. J. Kooijmans, Dario Papale, Timo Vesala, and Ivan Mammarella
Biogeosciences, 19, 4067–4088, https://doi.org/10.5194/bg-19-4067-2022, https://doi.org/10.5194/bg-19-4067-2022, 2022
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Four different methods for quantifying photosynthesis (GPP) at ecosystem scale were tested, of which two are based on carbon dioxide (CO2) and two on carbonyl sulfide (COS) flux measurements. CO2-based methods are traditional partitioning, and a new method uses machine learning. We introduce a novel method for calculating GPP from COS fluxes, with potentially better applicability than the former methods. Both COS-based methods gave on average higher GPP estimates than the CO2-based estimates.
Lutz Beckebanze, Benjamin R. K. Runkle, Josefine Walz, Christian Wille, David Holl, Manuel Helbig, Julia Boike, Torsten Sachs, and Lars Kutzbach
Biogeosciences, 19, 3863–3876, https://doi.org/10.5194/bg-19-3863-2022, https://doi.org/10.5194/bg-19-3863-2022, 2022
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In this study, we present observations of lateral and vertical carbon fluxes from a permafrost-affected study site in the Russian Arctic. From this dataset we estimate the net ecosystem carbon balance for this study site. We show that lateral carbon export has a low impact on the net ecosystem carbon balance during the complete study period (3 months). Nevertheless, our results also show that lateral carbon export can exceed vertical carbon uptake at the beginning of the growing season.
Shahar Baram, Asher Bar-Tal, Alon Gal, Shmulik P. Friedman, and David Russo
Biogeosciences, 19, 3699–3711, https://doi.org/10.5194/bg-19-3699-2022, https://doi.org/10.5194/bg-19-3699-2022, 2022
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Static chambers are the most common tool used to measure greenhouse gas (GHG) fluxes. We tested the impact of such chambers on nitrous oxide emissions in drip irrigation. Field measurements and 3-D simulations show that the chamber base drastically affects the water and nutrient distribution in the soil and hence the measured GHG fluxes. A nomogram is suggested to determine the optimal diameter of a cylindrical chamber that ensures minimal disturbance.
Tracy E. Rankin, Nigel T. Roulet, and Tim R. Moore
Biogeosciences, 19, 3285–3303, https://doi.org/10.5194/bg-19-3285-2022, https://doi.org/10.5194/bg-19-3285-2022, 2022
Short summary
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Peatland respiration is made up of plant and peat sources. How to separate these sources is not well known as peat respiration is not straightforward and is more influenced by vegetation dynamics than previously thought. Results of plot level measurements from shrubs and sparse grasses in a woody bog show that plants' respiration response to changes in climate is related to their different root structures, implying a difference in the mechanisms by which they obtain water resources.
Alison Bressler and Jennifer Blesh
Biogeosciences, 19, 3169–3184, https://doi.org/10.5194/bg-19-3169-2022, https://doi.org/10.5194/bg-19-3169-2022, 2022
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Our field experiment tested if a mixture of a nitrogen-fixing legume and non-legume cover crop could reduce nitrous oxide (N2O) emissions following tillage, compared to the legume grown alone. We found higher N2O following both legume treatments, compared to those without, and lower emissions from the cover crop mixture at one of the two test sites, suggesting that interactions between cover crop types and soil quality influence N2O emissions.
Sari Juutinen, Mika Aurela, Juha-Pekka Tuovinen, Viktor Ivakhov, Maiju Linkosalmi, Aleksi Räsänen, Tarmo Virtanen, Juha Mikola, Johanna Nyman, Emmi Vähä, Marina Loskutova, Alexander Makshtas, and Tuomas Laurila
Biogeosciences, 19, 3151–3167, https://doi.org/10.5194/bg-19-3151-2022, https://doi.org/10.5194/bg-19-3151-2022, 2022
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We measured CO2 and CH4 fluxes in heterogenous Arctic tundra in eastern Siberia. We found that tundra wetlands with sedge and grass vegetation contributed disproportionately to the landscape's ecosystem CO2 uptake and CH4 emissions to the atmosphere. Moreover, we observed high CH4 consumption in dry tundra, particularly in barren areas, offsetting part of the CH4 emissions from the wetlands.
Jessica Plein, Rulon W. Clark, Kyle A. Arndt, Walter C. Oechel, Douglas Stow, and Donatella Zona
Biogeosciences, 19, 2779–2794, https://doi.org/10.5194/bg-19-2779-2022, https://doi.org/10.5194/bg-19-2779-2022, 2022
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Tundra vegetation and the carbon balance of Arctic ecosystems can be substantially impacted by herbivory. We tested how herbivory by brown lemmings in individual enclosure plots have impacted carbon exchange of tundra ecosystems via altering carbon dioxide (CO2) and methane (CH4) fluxes. Lemmings significantly decreased net CO2 uptake while not affecting CH4 emissions. There was no significant difference in the subsequent growing season due to recovery of the vegetation.
Jenie Gil, Maija E. Marushchak, Tobias Rütting, Elizabeth M. Baggs, Tibisay Pérez, Alexander Novakovskiy, Tatiana Trubnikova, Dmitry Kaverin, Pertti J. Martikainen, and Christina Biasi
Biogeosciences, 19, 2683–2698, https://doi.org/10.5194/bg-19-2683-2022, https://doi.org/10.5194/bg-19-2683-2022, 2022
Short summary
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N2O emissions from permafrost soils represent up to 11.6 % of total N2O emissions from natural soils, and their contribution to the global N2O budget will likely increase due to climate change. A better understanding of N2O production from permafrost soil is needed to evaluate the role of arctic ecosystems in the global N2O budget. By studying microbial N2O production processes in N2O hotspots in permafrost peatlands, we identified denitrification as the dominant source of N2O in these surfaces.
Cited articles
Alsdorf, D., Beighley, E., Laraque, A., Lee, H., Tshimanga, R., O'Loughlin, F.,
Mahé, G., Dinga, B., Moukandi, G., and Spencer, R. G. M.: Opportunities for
hydrologic research in the Congo Basin, Rev. Geophys., 54, 378–409,
https://doi.org/10.1002/2016RG000517, 2016. a
Andrews, J. A., Matamala, R., Westover, K. M., and Schlesinger, W. H.:
Temperature effects on the diversity of soil heterotrophs and the
δ13C of soil-respired CO2, Soil Biol. Biochem., 32,
699–706, https://doi.org/10.1016/S0038-0717(99)00206-0, 2000. a
Arias‐Navarro, C., Díaz‐Pinés, E., Klatt, S., Brandt, P., Rufino, M. C.,
Butterbach‐Bahl, K., and Verchot, L. V.: Spatial variability of soil N2O
and CO2 fluxes in different topographic positions in a tropical montane
forest in Kenya, J. Geophys. Res.-Biogeo., 122,
514–527, https://doi.org/10.1002/2016JG003667, 2017. a
Barthel, M., Hammerle, A., Sturm, P., Baur, T., Gentsch, L., and Knohl, A.: The
diel imprint of leaf metabolism on the δ13C signal of soil
respiration under control and drought conditions, New Phytol., 192,
925–938, https://doi.org/10.1111/j.1469-8137.2011.03848.x, 2011. a
Barton, K.: MuMin: Multi-Model Inference, r package version
1.43.6, available at:
https://CRAN.R-project.org/package=MuMIn (last access: 14 April 2020), 2019. a
Bastviken, D., Cole, J. J., Pace, M. L., and Van de Bogert, M. C.: Fates of
methane from different lake habitats: Connecting whole-lake budgets and
CH4 emissions, J. Geophys. Res.-Biogeo., 113, G02024,
https://doi.org/10.1029/2007JG000608, 2008. a
Baumgartner, S., Barthel, M., Drake, T. W., Makelele, I. A., Mugula, J. K., Summerauer, L., Gallarotti, N., Ntaboba, L. C., Van Oost, K., Boeckx, P., Doetterl, S., Werner, R. A., and Six, J.: Dataset: Seasonality, drivers, and isotopic composition of soil CO2 fluxes from tropical forests of the Congo Basin, Zenodo, https://doi.org/10.5281/zenodo.3757768, 2020. a
Bauters, M., Verbeeck, H., Demol, M., Bruneel, S., Taveirne, C., Van der Heyden, D., Cizungu, L., and Boeckx, P.: Parallel functional and stoichiometric trait shifts in South American and African forest communities with elevation, Biogeosciences, 14, 5313–5321, https://doi.org/10.5194/bg-14-5313-2017, 2017. a
Bauters, M., Verbeeck, H., Rütting, T., Barthel, M., Bazirake Mujinya, B.,
Bamba, F., Bodé, S., Boyemba, F., Bulonza, E., Carlsson, E., Eriksson, L.,
Makelele, I., Six, J., Cizungu Ntaboba, L., and Boeckx, P.: Contrasting
nitrogen fluxes in African tropical forests of the Congo Basin, Ecol.
Monogr., 89, e01342, https://doi.org/10.1002/ecm.1342, 2019. a, b, c, d
Blessing, C., Barthel, M., and Buchmann, N.: Strong Coupling of Shoot
Assimilation and Soil Respiration during Drought and Recovery Periods in
Beech As Indicated by Natural Abundance δ13C Measurements,
Front. Plant Sci., 7, 1710, https://doi.org/10.3389/fpls.2016.01710, 2016. a
Bond-Lamperty, B., Bailey, V. L., Chen, M., Gough, C. M., and Vargas, R.:
Globally rising soil heterotrophic respiration over recent decades, Nature,
560, 80–83, https://doi.org/10.1038/s41586-018-0358-x, 2018. a, b
Borken, W. and Matzner, E.: Reappraisal of drying and wetting effects on C and
N mineralization and fluxes in soils, Glob. Change Biol., 15, 808–824,
https://doi.org/10.1111/j.1365-2486.2008.01681.x, 2009. a
Bowling, D. R., McDowell, N. G., Bond, B. J., Law, B. E., and Ehleringer,
J. R.: 13C content of ecosystem respiration is linked to precipitation
and vapor pressure deficit, Oecologia, 131, 113–124,
https://doi.org/10.1007/s00442-001-0851-y, 2002. a
Bréchet, L., Ponton, S., Alméras, T., Bonal, D., and Epron, D.: Does
spatial distribution of tree size account for spatial variation in soil
respiration in a tropical forest?, Plant Soil, 347, 293–303,
https://doi.org/10.1007/s11104-011-0848-1, 2011. a
Brüggemann, N., Gessler, A., Kayler, Z., Keel, S. G., Badeck, F., Barthel, M., Boeckx, P., Buchmann, N., Brugnoli, E., Esperschütz, J., Gavrichkova, O., Ghashghaie, J., Gomez-Casanovas, N., Keitel, C., Knohl, A., Kuptz, D., Palacio, S., Salmon, Y., Uchida, Y., and Bahn, M.: Carbon allocation and carbon isotope fluxes in the plant-soil-atmosphere continuum: a review, Biogeosciences, 8, 3457–3489, https://doi.org/10.5194/bg-8-3457-2011, 2011. a
Buchmann, N., Guehl, J.-M., Barigah, T. S., and Ehleringer, J. R.:
Interseasonal comparison of CO2 concentrations, isotopic composition, and
carbon dynamics in an Amazonian rainforest (French Guiana), Oecologia, 110,
120–131, https://doi.org/10.1007/s004420050140, 1997. a
Chen, L., Flynn, D. F. B., Zhang, X., Gao, X., Lin, L., Luo, J., and Zhao, C.:
Divergent patterns of foliar δ13C and δ15N in Quercus aquifolioides with
an altitudinal transect on the Tibetan Plateau: an integrated study based on
multiple key leaf functional traits, J. Plant Ecol., 8, 303–312,
https://doi.org/10.1093/jpe/rtu020, 2014. a
Courtois, E. A., Stahl, C., Van den Berge, J., Bréchet, L.,
Van Langenhove, L., Richter, A., Urbina, I., Soong, J. L., Peñuelas,
J., and Janssens, I. A.: Spatial Variation of Soil CO2, CH4 and N2O
Fluxes Across Topographical Positions in Tropical Forests of the Guiana
Shield, Ecosystems, 22, 228–228, https://doi.org/10.1007/s10021-018-0281-x, 2018. a, b, c, d
Davidson, E. A. and Janssens, I. A.: Temperature sensitivity of soil carbon
decomposition and feedbacks to climate change, Nature, 440, 165–173,
https://doi.org/10.1038/nature04514, 2006. a
Davidson, E. A., Ishida, F. Y., and Nepstad, D. C.: Effects of an experimental
drought on soil emissions of carbon dioxide, methane, nitrous oxide, and
nitric oxide in a moist tropical forest, Glob. Change Biol., 10, 718–730,
https://doi.org/10.1111/j.1365-2486.2004.00762.x, 2004. a
de Araújo, A. C., Ometto, J. P. H. B., Dolman, A. J., Kruijt, B., Waterloo, M. J., and Ehleringer, J. R.: Implications of CO2 pooling on δ13C of ecosystem respiration and leaves in Amazonian forest, Biogeosciences, 5, 779–795, https://doi.org/10.5194/bg-5-779-2008, 2008. a, b
Doetterl, S., Kearsley, E., Bauters, M., Hufkens, K., Lisingo, J., Baert, G.,
Verbeeck, H., and Boeckx, P.: Aboveground vs. Belowground Carbon Stocks in
African Tropical Lowland Rainforest: Drivers and Implications, PLOS ONE, 10,
1–14, https://doi.org/10.1371/journal.pone.0143209, 2015. a
Doetterl, S., Berhe, A. A., Arnold, C., Bodé, S., Fiener, P., Finke, P.,
Fuchslueger, L., Griepentrog, M., Harden, J. W., Nadeu, E., Schnecker, J.,
Six, J., Trumbore, S., Van Oost, K., Vogel, C., and Boeckx, P.: Links among
warming, carbon and microbial dynamics mediated by soil mineral weathering,
Nat. Geosci., 11, 589–593, https://doi.org/10.1038/s41561-018-0168-7, 2018. a, b, c
Doff Sotta, E., Meir, P., Malhi, Y., Donato nobre, A., Hodnett, M., and Grace,
J.: Soil CO2 efflux in a tropical forest in the central Amazon, Glob.
Change Biol., 10, 601–617, https://doi.org/10.1111/j.1529-8817.2003.00761.x, 2004. a, b, c
Ekblad, A. and Högberg, P.: Natural abundance of 13C in CO2 respired
from forest soils reveals speed of link between tree photosynthesis and root
respiration, Oecologia, 127, 305–308, https://doi.org/10.1007/s004420100667, 2001. a, b, c
Epron, D., Nouvellon, Y., Mareschal, L., e Moreira, R. M., Koutika, L.-S.,
Geneste, B., Delgado-Rojas, J. S., Laclau, J.-P., Sola, G.,
de Moraes Gonçalves, J. L., and Bouillet, J.-P.: Partitioning of net primary
production in Eucalyptus and Acacia stands and in mixed-species plantations:
Two case-studies in contrasting tropical environments, Forest Ecol.
Manage., 301, 102–111,
https://doi.org/10.1016/j.foreco.2012.10.034, 2013. a
Farquhar, G. D. and Richards, R. A.: Isotopic Composition of Plant Carbon
Correlates With Water-Use Efficiency of Wheat Genotypes, Funct. Plant
Biol., 11, 539–552, https://doi.org/10.1071/PP9840539, 1984. a
Friedlingstein, P., Jones, M. W., O'Sullivan, M., Andrew, R. M., Hauck, J., Peters, G. P., Peters, W., Pongratz, J., Sitch, S., Le Quéré, C., Bakker, D. C. E., Canadell, J. G., Ciais, P., Jackson, R. B., Anthoni, P., Barbero, L., Bastos, A., Bastrikov, V., Becker, M., Bopp, L., Buitenhuis, E., Chandra, N., Chevallier, F., Chini, L. P., Currie, K. I., Feely, R. A., Gehlen, M., Gilfillan, D., Gkritzalis, T., Goll, D. S., Gruber, N., Gutekunst, S., Harris, I., Haverd, V., Houghton, R. A., Hurtt, G., Ilyina, T., Jain, A. K., Joetzjer, E., Kaplan, J. O., Kato, E., Klein Goldewijk, K., Korsbakken, J. I., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lenton, A., Lienert, S., Lombardozzi, D., Marland, G., McGuire, P. C., Melton, J. R., Metzl, N., Munro, D. R., Nabel, J. E. M. S., Nakaoka, S.-I., Neill, C., Omar, A. M., Ono, T., Peregon, A., Pierrot, D., Poulter, B., Rehder, G., Resplandy, L., Robertson, E., Rödenbeck, C., Séférian, R., Schwinger, J., Smith, N., Tans, P. P., Tian, H., Tilbrook, B., Tubiello, F. N., van der Werf, G. R., Wiltshire, A. J., and Zaehle, S.: Global Carbon Budget 2019, Earth Syst. Sci. Data, 11, 1783–1838, https://doi.org/10.5194/essd-11-1783-2019, 2019. a
Garcia-Montiel, D. C., Melillo, J. M., Steudler, P. A., Tian, H., Neill, C.,
Kicklighter, D. W., Feigl, B., Piccolo, M., and Cerri, C. C.: Emissions of
N2O and CO2 from terra firme forests in Rondonia, Brazil, Ecol.
Appl., 14, 214–220, https://doi.org/10.1890/01-6023, 2004. a
Hashimoto, S., Tanaka, N., Suzuki, M., Inoue, A., Takizawa, H., Kosaka, I.,
Tanaka, K., Tantasirin, C., and Tangtham, N.: Soil respiration and soil
CO2 concentration in a tropical forest, Thailand, J. Forest
Res., 9, 75–79, https://doi.org/10.1007/s10310-003-0046-y, 2004. a
Hopkins, A. and Del Prado, A.: Implications of climate change for grassland in
Europe: impacts, adaptations and mitigation options: a review, Grass
Forage Sci., 62, 118–126, https://doi.org/10.1111/j.1365-2494.2007.00575.x, 2007. a
Hultine, K. R. and Marshall, J. D.: Altitude trends in conifer leaf morphology
and stable carbon isotope composition, Oecologia, 123, 32–40,
https://doi.org/10.1007/s004420050986, 2000. a
Hutchinson, G. L. and Mosier, A. R.: Improved Soil Cover Method for Field
Measurement of Nitrous Oxide Fluxes, Soil. Sci. Soc. Am. J., 45, 311–316,
https://doi.org/10.2136/sssaj1981.03615995004500020017x, 1981. a, b
Högberg, P., Nordgren, A., Buchmann, N., Taylor, A., Ekblad, A., Högberg, M.,
Nyberg, G., Ottosson-Löfvenius, M., and Read, D.: Large-scale forest
girdling shows that current photosynthesis drives soil respiration, Nature,
411, 789–92, https://doi.org/10.1038/35081058, 2001. a
Imani, G., Zapfack, L., Kalume, J., Riera, B., Cirimwami, L., and Boyemba, F.:
Woody vegetation groups and diversity along the altitudinal gradient in
mountain forest: case study of Kahuzi-Biega National Park and its
surroundings, RD Congo, Journal of Biodiversity and Environmental Sciences,
8, 134–150, 2016. a
Janssens, I. A., Barigah, S. T., and Ceulemans, R.: Soil CO2 efflux rates in
different tropical vegetation types in French Guiana, Ann. Sci.
Forest., 55, 671–680, https://doi.org/10.1051/forest:19980603, 1998. a, b, c
Jiang, Y., Zhou, L., Tucker, C. J., Raghavendra, A., Hua, W., Liu, Y. Y., and
Joiner, J.: Widespread increase of boreal summer dry season length over the
Congo rainforest, Nat. Clim. Change, 9, 617–622,
https://doi.org/10.1038/s41558-019-0512-y, 2019. a, b
Jones, A., Breuning-Madsen, H., Brossard, M., Dampha, A., Deckers, J., Dewitte,
O., Gallali, T., Hallett, S., Jones, R., Kilasara, M., Le Roux, P., Micheli,
E., Montanarella, L., Spaargaren, O., Thiobiano, L., Van Ranst, E., Yemefack,
M., and Zougmoré, R.: Soil Atlas of Africa, European Commission, Publication
Office of the European Union, Luxembourg, 2013. a, b
Kearsley, E., Verbeeck, H., Hufkens, K., Van de Perre, F., Doetterl, S., Baert,
G., Beeckman, H., Boeckx, P., and Huygens, D.: Functional community structure
of African monodominant Gilbertiodendron dewevrei forest influenced by local
environmental filtering, Ecol. Evol., 7, 295–304,
https://doi.org/10.1002/ece3.2589, 2017. a
Keeling, C. D.: The concentration and isotopic abundances of atmospheric carbon
dioxide in rural areas, Geochim. Cosmochim. Ac., 13, 322–334,
https://doi.org/10.1016/0016-7037(58)90033-4, 1958. a
Knohl, A., Werner, R., Geilmann, H., and Brand, W.: Kel-F (TM) discs improve
storage time of canopy air samples in 10-mL vials for CO2-delta C-13
analysis, Rapid Commun. Mass Sp., 18, 1663–1665,
https://doi.org/10.1002/rcm.1528, 2004. a
Körner, C., Farquhar, G. D., and Roksandic, Z.: A global survey of carbon
isotope discrimination in plants from high altitude, Oecologia, 74, 623–632,
https://doi.org/10.1007/BF00380063, 1988. a
Kuznetsova, A., Brockhoff, P. B., and Christensen, R. H. B.: lmerTest
Package: Tests in Linear Mixed Effects Models, J. Stat.
Softw., 82, 1–26, https://doi.org/10.18637/jss.v082.i13, 2017. a
Maldague, M. E. and Hilger, F.: Observations Faunastiques et Microbiologiques
Dans Quelques Biotopes Forestiers Equatoriaux, in: Soil Organisms: Proceedings of the colloquium on soil fauna, soil microflora and their relationships,
Oosterbeek, the Netherlands, 10–16 September 1962,
368–374, 1962. a, b
Manzoni, S., Moyano, F., Kätterer, T., and Schimel, J.: Modeling coupled
enzymatic and solute transport controls on decomposition in drying soils,
Soil Biol. Biochem., 95, 275–287,
https://doi.org/10.1016/j.soilbio.2016.01.006, 2016. a
McDowell, N. G., Bowling, D. R., Bond, B. J., Irvine, J. R., Law, B. E.,
Anthoni, P., and Ehleringer, J. R.: Response of the carbon isotopic content
of ecosystem, leaf, and soil respiration to meteorological and physiological
driving factors in a Pinus ponderosa ecosystem, Global Biogeochem. Cy.,
18, GB1013, https://doi.org/10.1029/2003GB002049, 2004. a
Melillo, J. M., McGuire, D. A., Kicklighter, D. W., Moore, Berrien, M. I.,
Vorosmarty, C. J., and Schloss, A. L.: Global Climate-Change and Terrestrial
Net Primary Production, Nature, 363, 234–240, https://doi.org/10.1038/363234a0, 1993. a
Merbold, L., Ardö, J., Arneth, A., Scholes, R. J., Nouvellon, Y., de Grandcourt, A., Archibald, S., Bonnefond, J. M., Boulain, N., Brueggemann, N., Bruemmer, C., Cappelaere, B., Ceschia, E., El-Khidir, H. A. M., El-Tahir, B. A., Falk, U., Lloyd, J., Kergoat, L., Le Dantec, V., Mougin, E., Muchinda, M., Mukelabai, M. M., Ramier, D., Roupsard, O., Timouk, F., Veenendaal, E. M., and Kutsch, W. L.: Precipitation as driver of carbon fluxes in 11 African ecosystems, Biogeosciences, 6, 1027–1041, https://doi.org/10.5194/bg-6-1027-2009, 2009. a
Moyano, F. E., Vasilyeva, N., Bouckaert, L., Cook, F., Craine, J., Curiel Yuste, J., Don, A., Epron, D., Formanek, P., Franzluebbers, A., Ilstedt, U., Kätterer, T., Orchard, V., Reichstein, M., Rey, A., Ruamps, L., Subke, J.-A., Thomsen, I. K., and Chenu, C.: The moisture response of soil heterotrophic respiration: interaction with soil properties, Biogeosciences, 9, 1173–1182, https://doi.org/10.5194/bg-9-1173-2012, 2012. a
Moyano, F. E., Manzoni, S., and Chenu, C.: Responses of soil heterotrophic
respiration to moisture availability: An exploration of processes and models,
Soil Biol. Biochem., 59, 72–85,
https://doi.org/10.1016/j.soilbio.2013.01.002, 2013. a
Nakagawa, S. and Schielzeth, H.: A general and simple method for obtaining R2
from generalized linear mixed-effects models, Methods Ecol.
Evol., 4, 133–142, https://doi.org/10.1111/j.2041-210x.2012.00261.x, 2013. a, b
Ogle, K.: Microbes weaken soil carbon sink, Nature, 560, 32–33,
https://doi.org/10.1038/d41586-018-05842-2, 2018. a
Ometto, J. P. H. B., Flanagan, L. B., Martinelli, L. A., Moreira, M. Z.,
Higuchi, N., and Ehleringer, J. R.: Carbon isotope discrimination in forest
and pasture ecosystems of the Amazon Basin, Brazil, Global Biogeochem.
Cy., 16, 56-1–56-10, https://doi.org/10.1029/2001GB001462, 2002. a
Palmer, P. I., Feng, L., Baker, D., Chevallier, F., Bösch, H., and Somkut, P.:
Net carbon emissions from African biosphere dominate pan-tropical atmospheric
CO2 signal, Nat. Commun., 10, 3344, https://doi.org/10.1038/s41467-019-11097-w,
2019. a
Pan, Y., Birdsey, R., Fang, J., Houghton, R., Kauppi, P., Kurz, W., Phillips,
O., Shvidenko, A., Lewis, S., Canadell, J., Ciais, P., Jackson, R., Pacala,
S., McGuire, A., Piao, S., Rautiainen, A., Sitch, S., and Hayes, D.: A Large
and Persistent Carbon Sink in the World's Forests, Science, 333, 988–993,
https://doi.org/10.1126/science.1201609, 2011. a
Pendall, E., Schwendemann, L., Rahn, T., Miller, J. B., Tans, P. P., and White,
J. W. C.: Land use and season affect fluxes of CO2, CH4, CO, N2O,
H2 and isotopic source signatures in Panama: evidence from nocturnal
boundary layer profiles, Glob. Change Biol., 16, 2721–2736,
https://doi.org/10.1111/j.1365-2486.2010.02199.x, 2010. a
Quay, P., King, S., Wilbur, D., Wofsy, S., and Rickey, J.: 13C ∕ 12C of
atmospheric CO2 in the Amazon Basin: Forest and river sources, J.
Geophys. Res.-Atmos., 94, 18327–18336,
https://doi.org/10.1029/JD094iD15p18327, 1989. a
Raich, J. W. and Schlesinger, W. H.: The global carbon dioxide flux in soil
respiration and its relationship to vegetation and climate, Tellus B, 44, 81–99,
https://doi.org/10.1034/j.1600-0889.1992.t01-1-00001.x, 1992. a
Raich, J. W., Potter, C. S., and Bhagawati, D.: Interannual variability in
global soil respiration, 1980–94, Glob. Change Biol., 8, 800–812,
https://doi.org/10.1046/j.1365-2486.2002.00511.x, 2002. a, b
R Development Core Team: R: A Language and Environment for Statistical
Computing, R Foundation for Statistical Computing, Vienna, Austria,
available at: http://www.R-project.org (last access: 14 April 2020), 2019. a
Rey, A., Pegoraro, E., Tedeschi, V., De Parri, I., Jarvis, P. G., and
Valentini, R.: Annual variation in soil respiration and its components in a
coppice oak forest in Central Italy, Glob. Change Biol., 8, 851–866,
https://doi.org/10.1046/j.1365-2486.2002.00521.x, 2002. a
Roderick, M. L. and Berry, S. L.: Linking wood density with tree growth and
environment: a theoretical analysis based on the motion of water, New
Phytol., 149, 473–485, https://doi.org/10.1046/j.1469-8137.2001.00054.x, 2001. a, b
Ruehr, N. K., Offermann, C. A., Gessler, A., Winkler, J. B., Ferrio, J. P.,
Buchmann, N., and Barnard, R. L.: Drought effects on allocation of recent
carbon: from beech leaves to soil CO2 efflux, New Phytol., 184,
950–961, https://doi.org/10.1111/j.1469-8137.2009.03044.x, 2009. a
Ruehr, N. K., Knohl, A., and Buchmann, N.: Environmental variables controlling
soil respiration on diurnal, seasonal and annual time-scales in a mixed
mountain forest in Switzerland, Biogeochemistry, 98, 153–170,
https://doi.org/10.1007/s10533-009-9383-z, 2010. a, b
Rustad, L. E., Huntington, T. G., and Boone, R. D.: Controls on Soil
Respiration: Implications for Climate Change, Biogeochemistry, 48, 1–6,
2000. a
Salmon, Y., Dietrich, L., Sevanto, S., Hölttä, T., Dannoura, M., and Epron,
D.: Drought impacts on tree phloem: from cell-level responses to ecological
significance, Tree Physiol., 39, 173–191, https://doi.org/10.1093/treephys/tpy153,
2019. a
Sotta, E. D., Veldkamp, E., Schwendemann, L., Guimaraes, B. R., Paixao, R. K.,
Ruivo, M. d. L. P., Lola da Costa, A. C., and Meir, P.: Effects of an induced
drought on soil carbon dioxide (CO2) efflux and soil CO2 production in
an Eastern Amazonian rainforest, Brazil, Glob. Change Biol., 13,
2218–2229, https://doi.org/10.1111/j.1365-2486.2007.01416.x, 2007. a
Sousa Neto, E., Carmo, J. B., Keller, M., Martins, S. C., Alves, L. F., Vieira, S. A., Piccolo, M. C., Camargo, P., Couto, H. T. Z., Joly, C. A., and Martinelli, L. A.: Soil-atmosphere exchange of nitrous oxide, methane and carbon dioxide in a gradient of elevation in the coastal Brazilian Atlantic forest, Biogeosciences, 8, 733–742, https://doi.org/10.5194/bg-8-733-2011, 2011.
a, b, c
Szaran, J.: Carbon isotope fractionation between dissolved and gaseous carbon
dioxide, Chem. Geol., 150, 331–337,
https://doi.org/10.1016/S0009-2541(98)00114-4, 1998. a
Townsend, A. R., Vitousek, P. M., and Trumbore, S. E.: Soil Organic Matter
Dynamics Along Gradients in Temperature and Land Use on the Island of Hawaii,
Ecology, 76, 721–733, https://doi.org/10.2307/1939339, 1995. a
Verhegghen, A., Mayaux, P., de Wasseige, C., and Defourny, P.: Mapping Congo Basin vegetation types from 300 m and 1 km multi-sensor time series for carbon stocks and forest areas estimation, Biogeosciences, 9, 5061–5079, https://doi.org/10.5194/bg-9-5061-2012, 2012. a
Waring, B. G. and Powers, J. S.: Unraveling the mechanisms underlying pulse
dynamics of soil respiration in tropical dry forests, Environ. Res.
Lett., 11, 105005, https://doi.org/10.1088/1748-9326/11/10/105005, 2016. a
Werner, C., Kiese, R., and Butterbach-Bahl, K.: Soil-atmosphere exchange of
N2O, CH4, and CO2 and controlling environmental factors for
tropical rain forest sites in western Kenya, J. Geophys.
Res., 112, D03308, https://doi.org/10.1029/2006JD007388, 2007. a
Werner, R. A. and Brand, W. A.: Referencing strategies and techniques in stable
isotope ratio analysis, Rapid Commun. Mass Sp., 15,
501–519, https://doi.org/10.1002/rcm.258, 2001. a
Werner, R. A., Rothe, M., and Brand, W. A.: Extraction of CO2 from air
samples for isotopic analysis and limits to ultra high precision
δ18O determination in CO2 gas, Rapid Commun. Mass
S., 15, 2152–2167, https://doi.org/10.1002/rcm.487, 2001. a
Xu, M. and Qi, Y.: Soil-surface CO2 efflux and its spatial and temporal
variations in a young ponderosa pine plantation in northern California,
Glob. Change Biol., 7, 667–677, https://doi.org/10.1046/j.1354-1013.2001.00435.x,
2001. a
Zeeman, M., Werner, R., Eugster, W., Siegwolf, R., Wehrle, G., Mohn, J., and
Buchmann, N.: Optimization of automated gas sample collection and isotope
ratio mass spectrometric analysis of δ13C of CO2 in air, Rapid
Commun. Mass Sp., 22, 3883–3892,
https://doi.org/10.1002/rcm.3772, 2008. a
Short summary
Soil respiration is an important carbon flux and key process determining the net ecosystem production of terrestrial ecosystems. The Congo Basin lacks studies quantifying carbon fluxes. We measured soil CO2 fluxes from different forest types in the Congo Basin and were able to show that, even though soil CO2 fluxes are similarly high in lowland and montane forests, the drivers were different: soil moisture in montane forests and C availability in the lowland forests.
Soil respiration is an important carbon flux and key process determining the net ecosystem...
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