Articles | Volume 12, issue 8
https://doi.org/10.5194/bg-12-2431-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-12-2431-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
24 Apr 2015
Research article |
| 24 Apr 2015
Dynamics of greenhouse gases (CO2, CH4, N2O) along the Zambezi River and major tributaries, and their importance in the riverine carbon budget
C. R. Teodoru
CORRESPONDING AUTHOR
KU Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium
F. C. Nyoni
University of Zambia, Integrated Water Research Management Centre, Lusaka, Zambia
A. V. Borges
University of Liège, Chemical Oceanography Unit, Liège, Belgium
F. Darchambeau
University of Liège, Chemical Oceanography Unit, Liège, Belgium
I. Nyambe
University of Zambia, Integrated Water Research Management Centre, Lusaka, Zambia
S. Bouillon
KU Leuven, Department of Earth and Environmental Sciences, Leuven, Belgium
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Short summary
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Biogeosciences, 11, 3547–3602, https://doi.org/10.5194/bg-11-3547-2014, https://doi.org/10.5194/bg-11-3547-2014, 2014
W. Thiery, A. Martynov, F. Darchambeau, J.-P. Descy, P.-D. Plisnier, L. Sushama, and N. P. M. van Lipzig
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T. R. Marwick, F. Tamooh, B. Ogwoka, C. Teodoru, A. V. Borges, F. Darchambeau, and S. Bouillon
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F. Tamooh, A. V. Borges, F. J. R. Meysman, K. Van Den Meersche, F. Dehairs, R. Merckx, and S. Bouillon
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Ensemble estimates of global wetland methane emissions over 2000–2020
A case study on topsoil removal and rewetting for paludiculture: effect on biogeochemistry and greenhouse gas emissions from Typha latifolia, Typha angustifolia, and Azolla filiculoides
Seasonal carbon fluxes from vegetation and soil in a Mediterranean non-tidal salt marsh
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
Tidal influence on carbon dioxide and methane fluxes from tree stems and soils in mangrove forests
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
Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in Northern Europe
Identifying landscape hot and cold spots of soil greenhouse gas fluxes by combining field measurements and remote sensing data
Explainable machine learning for modelling of net ecosystem exchange in boreal forest
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
Nathaniel B. Weston, Cynthia Troy, Patrick J. Kearns, Jennifer L. Bowen, William Porubsky, Christelle Hyacinthe, Christof Meile, Philippe Van Cappellen, and Samantha B. Joye
Biogeosciences, 21, 4837–4851, https://doi.org/10.5194/bg-21-4837-2024, https://doi.org/10.5194/bg-21-4837-2024, 2024
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Nitrous oxide (N2O) is a potent greenhouse and ozone-depleting gas produced largely from microbial nitrogen cycling processes, and human activities have resulted in increases in atmospheric N2O. We investigate the role of physical and chemical disturbances to soils and sediments in N2O production. We demonstrate that physicochemical perturbation increases N2O production, microbial community adapts over time, and initial perturbation appears to confer resilience to subsequent disturbance.
Sigrid Trier Kjær, Sebastian Westermann, Nora Nedkvitne, and Peter Dörsch
Biogeosciences, 21, 4723–4737, https://doi.org/10.5194/bg-21-4723-2024, https://doi.org/10.5194/bg-21-4723-2024, 2024
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Permafrost peatlands are thawing due to climate change, releasing large quantities of carbon that degrades upon thawing and is released as CO2, CH4 or dissolved organic carbon (DOC). We incubated thawed Norwegian permafrost peat plateaus and thermokarst pond sediment found next to permafrost for up to 350 d to measure carbon loss. CO2 production was initially the highest, whereas CH4 production increased over time. The largest carbon loss was measured at the top of the peat plateau core as DOC.
Silvie Lainela, Erik Jacobs, Stella-Theresa Luik, Gregor Rehder, and Urmas Lips
Biogeosciences, 21, 4495–4519, https://doi.org/10.5194/bg-21-4495-2024, https://doi.org/10.5194/bg-21-4495-2024, 2024
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We evaluate the variability of carbon dioxide and methane in the surface layer of the north-eastern basins of the Baltic Sea in 2018. We show that the shallower coastal areas have considerably higher spatial variability and seasonal amplitude of surface layer pCO2 and cCH4 than measured in the offshore areas of the Baltic Sea. Despite this high variability, caused mostly by coastal physical processes, the average annual air–sea CO2 fluxes differed only marginally between the sub-basins.
Martti Honkanen, Mika Aurela, Juha Hatakka, Lumi Haraguchi, Sami Kielosto, Timo Mäkelä, Jukka Seppälä, Simo-Matti Siiriä, Ken Stenbäck, Juha-Pekka Tuovinen, Pasi Ylöstalo, and Lauri Laakso
Biogeosciences, 21, 4341–4359, https://doi.org/10.5194/bg-21-4341-2024, https://doi.org/10.5194/bg-21-4341-2024, 2024
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The exchange of CO2 between the sea and the atmosphere was studied in the Archipelago Sea, Baltic Sea, in 2017–2021, using an eddy covariance technique. The sea acted as a net source of CO2 with an average yearly emission of 27.1 gC m-2 yr-1, indicating that the marine ecosystem respired carbon that originated elsewhere. The yearly CO2 emission varied between 18.2–39.2 gC m-2 yr-1, mostly due to the yearly variation of ecosystem carbon uptake.
Ralf C. H. Aben, Daniël van de Craats, Jim Boonman, Stijn H. Peeters, Bart Vriend, Coline C. F. Boonman, Ype van der Velde, Gilles Erkens, and Merit van den Berg
Biogeosciences, 21, 4099–4118, https://doi.org/10.5194/bg-21-4099-2024, https://doi.org/10.5194/bg-21-4099-2024, 2024
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Drained peatlands cause high CO2 emissions. We assessed the effectiveness of subsurface water infiltration systems (WISs) in reducing CO2 emissions related to increases in water table depth (WTD) on 12 sites for up to 4 years. Results show WISs markedly reduced emissions by 2.1 t CO2-C ha-1 yr-1. The relationship between the amount of carbon above the WTD and CO2 emission was stronger than the relationship between WTD and emission. Long-term monitoring is crucial for accurate emission estimates.
Ingeborg Bussmann, Eric P. Achterberg, Holger Brix, Nicolas Brüggemann, Götz Flöser, Claudia Schütze, and Philipp Fischer
Biogeosciences, 21, 3819–3838, https://doi.org/10.5194/bg-21-3819-2024, https://doi.org/10.5194/bg-21-3819-2024, 2024
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Methane (CH4) is an important greenhouse gas and contributes to climate warming. However, the input of CH4 from coastal areas to the atmosphere is not well defined. Dissolved and atmospheric CH4 was determined at high spatial resolution in or above the North Sea. The atmospheric CH4 concentration was mainly influenced by wind direction. With our detailed study on the spatial distribution of CH4 fluxes we were able to provide a detailed and more realistic estimation of coastal CH4 fluxes.
Niu Zhu, Jinniu Wang, Dongliang Luo, Xufeng Wang, Cheng Shen, and Ning Wu
Biogeosciences, 21, 3509–3522, https://doi.org/10.5194/bg-21-3509-2024, https://doi.org/10.5194/bg-21-3509-2024, 2024
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Our study delves into the vital role of subalpine forests in the Qinghai–Tibet Plateau as carbon sinks in the context of climate change. Utilizing advanced eddy covariance systems, we uncover their significant carbon sequestration potential, observing distinct seasonal patterns influenced by temperature, humidity, and radiation. Notably, these forests exhibit robust carbon absorption, with potential implications for global carbon balance.
Jessica Ashley Valerie Breavington, Alexandra Steckbauer, Chuancheng Fu, Mongi Ennasri, and Carlos Manuel Duarte
EGUsphere, https://doi.org/10.5194/egusphere-2024-1831, https://doi.org/10.5194/egusphere-2024-1831, 2024
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Mangroves are known for storing large amounts of carbon in their soils, but this is lower in the Red Sea due to challenging growth conditions. We collected soil cores over multiple seasons to measure soil properties, and the greenhouse gasses (GHG) of carbon dioxide and methane. We found that GHG emissions are generally a small offset to carbon storage but punctuated by periods of very high GHG emission and this variability is linked to multiple environmental and soil properties.
Colette L. Kelly, Nicole M. Travis, Pascale Anabelle Baya, Claudia Frey, Xin Sun, Bess B. Ward, and Karen L. Casciotti
Biogeosciences, 21, 3215–3238, https://doi.org/10.5194/bg-21-3215-2024, https://doi.org/10.5194/bg-21-3215-2024, 2024
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Nitrous oxide, a potent greenhouse gas, accumulates in regions of the ocean that are low in dissolved oxygen. We used a novel combination of chemical tracers to determine how nitrous oxide is produced in one of these regions, the eastern tropical North Pacific Ocean. Our experiments showed that the two most important sources of nitrous oxide under low-oxygen conditions are denitrification, an anaerobic process, and a novel “hybrid” process performed by ammonia-oxidizing archaea.
Hella van Asperen, Thorsten Warneke, Alessandro Carioca de Araújo, Bruce Forsberg, Sávio José Filgueiras Ferreira, Thomas Röckmann, Carina van der Veen, Sipko Bulthuis, Leonardo Ramos de Oliveira, Thiago de Lima Xavier, Jailson da Mata, Marta de Oliveira Sá, Paulo Ricardo Teixeira, Julie Andrews de França e Silva, Susan Trumbore, and Justus Notholt
Biogeosciences, 21, 3183–3199, https://doi.org/10.5194/bg-21-3183-2024, https://doi.org/10.5194/bg-21-3183-2024, 2024
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Carbon monoxide (CO) is regarded as an important indirect greenhouse gas. Soils can emit and take up CO, but, until now, uncertainty remains as to which process dominates in tropical rainforests. We present the first soil CO flux measurements from a tropical rainforest. Based on our observations, we report that tropical rainforest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.
Ihab Alfadhel, Ignacio Peralta-Maraver, Isabel Reche, Enrique P. Sánchez-Cañete, Sergio Aranda-Barranco, Eva Rodríguez-Velasco, Andrew S. Kowalski, and Penélope Serrano-Ortiz
EGUsphere, https://doi.org/10.5194/egusphere-2024-1562, https://doi.org/10.5194/egusphere-2024-1562, 2024
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Inland saline lakes are crucial in the global carbon cycle, but increased droughts may alter their carbon exchange capacity. We measured CO2 and CH4 fluxes in a Mediterranean saline lake using the Eddy Covariance method under dry and wet conditions. We found the lake acts as a carbon sink during wet periods but not during droughts. These results highlight the importance of saline lakes in carbon sequestration and their vulnerability to climate change-induced droughts.
Johnathan D. Maxey, Neil D. Hartstein, Hermann W. Bange, and Mortiz Müller
EGUsphere, https://doi.org/10.5194/egusphere-2024-1731, https://doi.org/10.5194/egusphere-2024-1731, 2024
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The distribution of N2O in fjord-like estuaries is poorly described in the southern hemisphere. Our study describes N2O distribution and its drivers in one such system Macquarie Harbour, Tasmania. Water samples were collected seasonally from 2022/2023. Results show the system is a sink for atmospheric N2O when river flow is high; and the system emits N2O when the river flow is low. N2O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.
Wael Al Hamwi, Maren Dubbert, Joerg Schaller, Matthias Lueck, Marten Schmidt, and Mathias Hoffmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-1806, https://doi.org/10.5194/egusphere-2024-1806, 2024
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We present a fully automatic, low-cost soil-plant enclosure system to monitor CO2 and ET fluxes within greenhouse experiments. It operates in two modes: independent, using low-cost sensors, and dependent, connecting multiple chambers to a single gas analyzer via a low-cost multiplexer. This system offers precise and accurate measurements, cost and labor efficiency, and high temporal resolution, enabling comprehensive monitoring of plant-soil responses to various treatments and conditions.
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.
Zhen Zhang, Benjamin Poulter, Joe R. Melton, William J. Riley, George H. Allen, David J. Beerling, Philippe Bousquet, Josep G. Canadell, Etienne Fluet-Chouinard, Philippe Ciais, Nicola Gedney, Peter O. Hopcroft, Akihiko Ito, Robert B. Jackson, Atul K. Jain, Katherine Jensen, Fortunat Joos, Thomas Kleinen, Sara Knox, Tingting Li, Xin Li, Xiangyu Liu, Kyle McDonald, Gavin McNicol, Paul A. Miller, Jurek Müller, Prabir K. Patra, Changhui Peng, Shushi Peng, Zhangcai Qin, Ryan M. Riggs, Marielle Saunois, Qing Sun, Hanqin Tian, Xiaoming Xu, Yuanzhi Yao, Xi Yi, Wenxin Zhang, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
EGUsphere, https://doi.org/10.5194/egusphere-2024-1584, https://doi.org/10.5194/egusphere-2024-1584, 2024
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This study assesses global methane emissions from wetlands between 2000 and 2020 using multiple models. We found that wetland emissions increased by 6–7 Tg CH4 per year in the 2010s compared to the 2000s. Rising temperatures primarily drove this increase, while changes in precipitation and CO2 levels also played roles. Our findings highlight the importance of wetlands in the global methane budget and the need for continuous monitoring to understand their impact on climate change.
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.
Lorena Carrasco-Barea, Dolors Verdaguer, Maria Gispert, Xavier D. Quintana, Hélène Bourhis, and Laura Llorens
EGUsphere, https://doi.org/10.5194/egusphere-2024-1320, https://doi.org/10.5194/egusphere-2024-1320, 2024
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Carbon dioxide fluxes have been measured seasonally in four plant species in a Mediterranean non-tidal salt marsh highlighting the high carbon removal potential that these species have. Carbon dioxide and methane emissions from soil showed high variability among the habitats studied and they were generally higher than those observed in tidal salt marshes. Our results are important to make more accurate predictions regarding carbon emissions from these ecosystems.
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.
Zhao-Jun Yong, Wei‐Jen Lin, Chiao-Wen Lin, and Hsing-Juh Lin Lin
EGUsphere, https://doi.org/10.5194/egusphere-2024-533, https://doi.org/10.5194/egusphere-2024-533, 2024
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This study is the first to simultaneously measure mangrove CH4 emissions from both stems and soils throughout tidal cycles. The stems served as both net CO2 and CH4 sources. Compared to those of the soils, the stems exhibited markedly lower CH4 emissions, but no difference in CO2 emissions. Sampling only during low tides might overestimate the stem CO2 and CH4 emissions on a diurnal scale. This study also highlights species distinctness (with pneumatophores) in the emissions.
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.
Tuula Aalto, Aki Tsuruta, Jarmo Mäkelä, Jurek Mueller, Maria Tenkanen, Eleanor Burke, Sarah Chadburn, Yao Gao, Vilma Mannisenaho, Thomas Kleinen, Hanna Lee, Antti Leppänen, Tiina Markkanen, Stefano Materia, Paul Miller, Daniele Peano, Olli Peltola, Benjamin Poulter, Maarit Raivonen, Marielle Saunois, David Wårlind, and Sönke Zaehle
EGUsphere, https://doi.org/10.5194/egusphere-2023-2873, https://doi.org/10.5194/egusphere-2023-2873, 2024
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Wetland methane responses to temperature and precipitation were studied in a boreal wetland-rich region in Northern Europe using ecosystem models, atmospheric inversions and up-scaled flux observations. The ecosystem models differed in their responses to temperature and precipitation and in their seasonality. However, multi-model means, inversions and up-scaled fluxes had similar seasonality, and they suggested co-limitation by temperature and precipitation.
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.
Ekaterina Ezhova, Topi Laanti, Anna Lintunen, Pasi Kolari, Tuomo Nieminen, Ivan Mammarella, Keijo Heljanko, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2023-2559, https://doi.org/10.5194/egusphere-2023-2559, 2023
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ML models are gaining popularity in biogeosciences. They are applied as gapfilling methods and used to upscale carbon fluxes to larger areas based on local measurements. In this study, we use Explainable ML methods to elucidate performance of machine learning models for carbon dioxide fluxes in boreal forest. We show that statistically equal models treat input variables differently. Explainable ML can help scientists to make informed solutions when applying ML models in their research.
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.
Cited articles
Abril, G., Martinez. J. M., Artigas, L. F., Moreira-Turcq. P., Benedetti, M. F., 5 Vidal, L., Meziane, T., Kin, J. H., Bernardes, M. C., Savoye, N., Deborde, J., Souza, E. L., Albéric, P., Landim de Souza, M. F., and Roland, F.: Amazon River carbon dioxide outgassing fuelled by wetlands, Nature, 505, 395–398, https://doi.org/10.1038/nature12797, 2014.
Abril, G., Bouillon, S., Darchambeau, F., Teodoru, C. R., Marwick, T. R., Tamooh, F., Ochieng Omengo, F., Geeraert, N., Deirmendjian, L., Polsenaere, P., and Borges, A. V.: Technical Note: Large overestimation of pCO2 calculated from pH and alkalinity in acidic, organic-rich freshwaters, Biogeosciences, 12, 67–78, https://doi.org/10.5194/bg-12-67-2015, 2015.
Amiotte-Suchet, P., Aubert, D., Probst, J. L., Gauthier-Lafaye, F., Probst, A., Andreux, F., and Viville, D.: δ13C pattern of dissolved inorganic carbon in a small granitic catchment: the Strengbach case study (Vosges mountains, France), Chem. Geol., 159, 129–145, 1999.
Ashton, P. J., Love, D., Mahachi, H., and Dirks, P. H. G. M.: An overview of the impact of mining and mineral processing operations on water resources and water quality in the Zambezi, Limpopo and Olifants Catchments in Southern Africa., Contract Report to the Mining, Minerals and Sustainable Development (SOUTHERN AFRICA), Project by CSIR-Environmentek, Pretoria, South Africa and Geology Department, University of Zimbabwe, Harare, Zimbabwe, Rep. ENV-P-C 2001–042, 336 pp., available at: http://pubs.iied.org/pdfs/G00599.pdf (last access: 15 September 2014), 2001.
Aufdenkampe, E. K., Mayorga, E., Raymond, P. A., Melack, J. M., Doney, S. C., Alin, S. R., Aalto, R. E., and Yoo, K.: Rivers key to coupling biogeochemical cycles between land, oceans and atmosphere, Front. Ecol. Environ. 9, 53–60, https://doi.org/10.1890/100014, 2011.
Bastviken, D., Tranvik, L. J., Downing, J. A., Crill, P. M., and Enrich-Prast, A.: Freshwater methane emissions offset the continental carbon sink, Science, 331, 6013, 50, https://doi.org/10.1126/science.1196808, 2011.
Battin, T. J., Luyssaert, S., Kaplan, L. A., Aufdenkampe, A. K., Richter, A., and Tranvik, L. J.: The boundless carbon cycle, Nat. Geosci., 2, 598–600, https://doi.org/10.1038/ngeo618, 2009.
Beilfuss, R. and dos Santos, D.: Patterns of hydrological change in the Zambezi Delta, Mozambique, Working Paper #2: Program for the sustainable management of Cahora Bassa Dam and the Lower Zambezi Valley, USA, International Crane Foundation, Direcção Naçional de Aguas, Mozambique, 2001.
Berggren, M., Lapierre, J.-F., and del Giorgio, P. A.: Magnitude and regulation of bacterioplankton respiratory quotient across freshwater environmental gradients, ISME J., 6, 984–993, https://doi.org/10.1038/ismej.2011.157, 2012.
Bouillon, S., Abril, G., Borges, A. V., Dehairs, F., Govers, G., Hughes, H. J., Merckx, R., Meysman, F. J. R., Nyunja, J., Osburn, C., and Middelburg, J. J.: Distribution, origin and cycling of carbon in the Tana River (Kenya): a dry season basin-scale survey from headwaters to the delta, Biogeosciences, 6, 2475–2493, https://doi.org/10.5194/bg-6-2475-2009, 2009.
Bouillon, S., Yambélé, A., Spencer, R. G. M., Gillikin, D. P., Hernes, P. J., Six, J., Merckx, R., and Borges, A. V.: Organic matter sources, fluxes and greenhouse gas exchange in the Oubangui River (Congo River basin), Biogeosciences, 9, 2045–2062, https://doi.org/10.5194/bg-9-2045-2012, 2012.
Bouillon, S., Yambélé, A., Gillikin, D. P., Teodoru, C. R., Darchambeau, F., Lambert, T., and Borges, A. V.: Contrasting biogeochemical characteristics of the Oubangui River and tributaries (Congo River basin), Sci. Rep., 4, 1–10, https://doi.org/10.1038/srep05402, 2014.
Briggs, D. A. and Mitchell, C. J.: Mineralogy and beneficiation of some industrial minerals from Zambia, Zamb, J. Appl. Earth Sci., 5, 18–27, 1991.
Butman, D. and Raymond, P. A.: Significant efflux of carbon dioxide from streams and rivers in the United States, Nat. Geosci., 4, 839–842, https://doi.org/10.1038/ngeo1294, 2011.
Cole, J. J. and Caraco, N. F.: Carbon in catchments: connecting terrestrial carbon losses with aquatic metabolism, Mar. Freshwater Res., 52, 101–110, 2001.
Cole, J. J., Prairie, Y. T., Caraco, N. F., McDowell, W. H., Tranvik, L. J., Striegl, R. G., Duarte, C. M., Kortelainen, P., Downing, J. A., Middelburg, J. J., and Melack, J.: Plumbing the global carbon cycle: integrating inland waters into the terrestrial carbon budget, Ecosystems, 10, 171–184, 2007.
Chenje, M.: State of the Environment Zambezi Basin 2000, SADC, IUCN, ZRA, and SARDC, Maseru, Lusaka and Harare, 334 pp., ISBN 978-1-77910-009-2, 2000.
Dauchez, S., Legendre, L., and Fortier, L.: Assessment of simultaneous uptake of nitrogenous nutrients (15N) and inorganic carbon (13C) by natural phytoplankton populations, Mar. Biol., 123, 651–666, 1995.
Doctor, D. H., Kendall, C., Sebestyen, S. D., Shanley, J. B., Ohte, N., and Boyer, E. W.: Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream, Hydrol. Process., 22, 2410–2423, 2008.
Driscoll, C. T., Fuller, R. D., and Schecher, W. D.: The role of organic acids in the acidification of surface waters in the eastern US, Water Air Soil Poll., 43, 21–40, 1989.
Einola, E., Rantakari, M., Kankaala, P., Kortelainen, P., Ojala, A., Pajunen, H., Mäkelä, S., and Arvola, L.: Carbon pools and fluxes in a chain of five boreal lakes: a dry and wet year comparison, J. Geophys. Res., 116, G03009, https://doi.org/10.1029/2010JG001636, 2011.
Finlay, J. C.: Controls of streamwater dissolved inorganic carbon dynamics in a forested watershed, Biogeochemistry, 62, 231–252, https://doi.org/10.1023/A:1021183023963, 2003.
Finlay, J. C. and Kendall, C.: Stable isotope tracing of temporal and spatial variability in organic matter sources to freshwater ecosystems, in: Stable Isotopes in Ecology and Environmental Science, 2nd edn., edited by: Michener, R. and Lajtha, K., Blackwell Publishing, Oxford, UK, 283–333, 2007.
Garrels, R. M. and Mackenzie, F. T.: Evolution of Sedimentary Rocks, W. W. Norton, New York, 397 pp., 1971.
Gillikin, D. P. and Bouillon, S.: Determination of δ18O of water and δ13C of dissolved inorganic carbon using a simple modification of an elemental analyzer – isotope ratio mass spectrometer (EA-IRMS): an evaluation, Rapid Commun. Mass Sp., 21, 1475–1478, 2007.
Guasch, H., Armengol, J., Martí, E., and Sabater, S.: Diurnal variation in dissolved oxygen and carbon dioxide in two low-order streams, Water Res., 32, 1067–1074, https://doi.org/10.1016/S0043-1354(97)00330-8, 1998.
Guérin, F., Abril, G., Richard, S., Burban, B., Reynouard, C., Seyler, P., and Delmas, R.: Methane and carbon dioxide emissions from tropical reservoirs: significance of downstream rivers. Geophys. Res. Lett., 33, L21407, https://doi.org/10.1029/2006GL027929, 2006.
Hemold, H. F.: Acid neutralizing capacity, alkalinity, and acid-base status of natural waters containing organic acids, Environ. Sci. Technol., 24, 1486–1489, 1990.
Hunt, C. W., Salisbury, J. E., and Vandemark, D.: Contribution of non-carbonate anions to total alkalinity and overestimation of pCO2 in New England and New Brunswick rivers, Biogeosciences, 8, 3069–3076, https://doi.org/10.5194/bg-8-3069-2011, 2011.
IPCC: Working group I contribution to the fifth assessment report (AR5) of the intergovernmental panel on climate change, in: Climate Change 2013: The Physical Science Basis, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1552 pp., 2013.
Kling, G. W, Kipphut, G. W., and Miller, M. C.: Arctic lakes and streams as gas conduits to the atmosphere: implications for tundra carbon budgets, Science, 251, 298–301, https://doi.org/10.1126/science.251.4991.298, 1991.
Kling, H., Stanzel, P., and Preishuber, M.: Impact modelling of water resources development and climate scenarios on Zambezi River discharge, J. Hydrol. Reg. Stud., 1, 17–43 2014.
Koné, Y. J. M., Abril, G., Kouadio, K. N., Delille, B., and Borges, A. V.: Seasonal variability of carbon dioxide in the rivers and lagoons of Ivory Coast (West Africa), Estuar. Coast., 32, 246–260, 2009.
Koné, Y. J. M., Abril, G., Delille, B., and Borges, A. V.: Seasonal variability of methane in the rivers and lagoons of Ivory Coast (West Africa), Biogeochemistry, 100, 21–37, 2010.
Kunz, M. J., Anselmetti, F. S., Wuestm, A., Wehrli, B., Vollenweider, A., Thuring, S., and Senn, D. B.: Sediment accumulation and carbon, nitrogen, and phosphorus deposition in the large tropical reservoir Lake Kariba (Zambia/Zimbabwe), J. Geophys. Res., 116, G03003, https://doi.org/10.1029/2010JG001538, 2011a.
Kunz, M. J., Wuest, A., Wehrli, B., Landert, J., and Senn, D. B.: Impact of a large tropical reservoir on riverine transport of sediment, carbon and nutrients to downstream wetlands, Water Resour. Res., 47, W12531, https://doi.org/10.1029/2011WR010996, 2011b.
Kunz, M. J., Senn, D. B., Wehrli, B., Mwelwa, E. M., and Wüest, A.: Optimizing turbine withdrawal from a tropical reservoir for improved water quality in downstream wetlands. Water Resour. Res, 49, 1–15, https://doi.org/10.1002/wrcr.20358, 2013.
Lambert, T., Darchambeau, F., Bouillon, S., Alhou, B., Mbega, J - D, Teodoru, C. R., Nyoni, F. C., and A V Borges, A. V.: The effect of vegetation cover on the spatial and temporal variability of dissolved organic carbon and chromophoric dissolved organic matter in large African rivers, submitted, 2015.
Lewis, E. and Wallace, D. W. R.: Program developed for CO2 system calculations, ORNL/CDIAC-105, published by Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, 1998.
Ludwig, W., Probst, J.-L., and Kempe, S.: Predicting the oceanic input of organic carbon by continental erosion, Global Biogeochem. Cy., 10, 23–41, 1996.
Mann, P. J., Spencer, E. G. M., Dinga., B. J., Poulsen, J. R., Hernes, P. J., Fiske, G., Salter, M. E., Wang, Z. A., Hoering, K. A., Six, J., and Holmes, R. M.: The biogeochemistry of carbon across a gradient of streams and rivers within the Congo Basin, J. Geophys. Res.-Biogeo., 119, 687–702, 2014.
Marwick, T. R., Tamooh, F., Ogwoka, B., Teodoru, C., Borges, A. V., Darchambeau, F., and Bouillon, S.: Dynamic seasonal nitrogen cycling in response to anthropogenic N loading in a tropical catchment, Athi-Galana-Sabaki River, Kenya, Biogeosciences, 11, 443–460, https://doi.org/10.5194/bg-11-443-2014, 2014.
McCartney, M. P. and Houghton-Carr, H. A.: Modelling approach to assess inter-sectoral competition for water resources in the Kafue Flats, Zambia, Water Environ. J., 12, 101–106, https://doi.org/10.1111/j.1747-6593.1998.tb00157.x, 1998.
McCartney, M., Cai, X., and Smakhtin, V.: Evaluating the flow regulating functions of natural ecosystems in the Zambezi River Basin, IWMI Res. Rep. 148, International Water Management Institute (IWMI), Colombo, Sri Lanka, 59 pp., https://doi.org/10.5337/2013.206, 2013.
Mengis, M. R., Gächter, R., and Wehrli, B.: Sources and sinks of nitrous oxide (N2O) in deep lakes, Biogeochemistry, 38, 281–301, 1997.
Meybeck, M.: Global chemical-weathering of surficial rocks estimated from river dissolved loads, Am. J. Sci., 287, 401–428, 1987.
Millero, F. J.: The thermodynamics of the carbonic acid system in seawater, Geochim. Cosmochim. Ac., 43, 1651–1661, 1979.
Moore, A. E., Cotterill, F. P. D., Main, M. P. L., and Williams, H. B.: The Zambezi River, in: Large Rivers: Geomorphology and Management, edited by: Gupta, A., John Wiley & Sons, Ltd, Chichester, UK, 311–333, 2007.
Mook, W. G., Koopmans, M., Carter, A. F., and Keeling, C. D.: Seasonal, latitudinal, and secular variations in the abundance and isotopic ratios of atmospheric carbon dioxide: 1. Results from land stations, J. Geophys. Res., 88, 10915–10933, 1983.
Mumba, M. and Thompson, J. R.: Hydrological and ecological impacts of dams on the Kafue Flats floodplain system, southern Zambia, Phys. Chem. Earth, 30, 442–447, 2005.
Parker, S. R., Poulson, S. R., Gammons, C. H., and Degrandpre, M. D.: Biogeochemical controls on diel cycling of stable isotopes of dissolved O2 and dissolved inorganic carbon in the Big Hole River, Montana, Environ. Sci. Technol., 39, 7134–7140, 2005.
Rantakari, M. and Kortelainen, P.: Controls of total organic and inorganic carbon in randomly selected Boreal lakes in varied catchments, Biogeochemistry, 91, 151–162, 2008.
Raymond, P. A., Zappa, C. J., Butman, D., Bott, T. L., Potter, C., Mulholland, P., Laursen, A. E., McDowell, W. H., and Newbold, D.: Scaling the gas transfer velocity and hydraulic geometry in streams and small rivers, Limnol. Oceanogr., 2, 41–53, https://doi.org/10.1215/21573689-1597669, 2012.
Raymond, P. A., Hartmann, J., Lauerwald, R., Sobek, S., McDonald, C., Hoover, M., Butman, D., Striegl, R., Mayorga, E., Humborg, C., Kortelainen, P., Dürr, H., Meybeck, M., Ciais, P., and Guth, P.: Global carbon dioxide emissions from inland waters, Nature, 503, 355–359, https://doi.org/10.1038/nature12760, 2013.
Richardson, D. C., Newbold, J. D., Aufdenkampe, A. K., Taylor, P. G., and Kaplan, L. A.: Measuring heterotrophic respiration rates of suspended particulate organic carbon from stream ecosystems, Limnol. Oceanogr.-Meth., 11, 247–261, 2013.
Richey, J. E., Devol, A. H., Wofy, S. C., Victoria, R., and Riberio, M. N. G.: Biogenic gases and the oxidation and reduction of carbon in Amazon River and floodplain waters, Limnol. Oceanogr., 33, 551–561, 1988.
Richey, J. E., Melack, J. M., Aufdenkampe, A. K., Ballester, V. M., and Hess, L.: Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2, Nature, 416, 617–620, 2002.
SADC, SARDC, GRID-Arendal, and ZAMCOM: Zambezi River Basin Atlas of the Changing Environment, Southern African Development Community (SADC), Southern African Research and Documentation Centre (SARDC), United Nations Environment Programme (UNEP)/GRID-Arendal, Zambezi Watercourse Commission (ZAMCOM), Gaborone, Harare and Arendal, 134 pp., 2012.
Sawakuchi, H. O., Bastviken, D., Sawakuchi, A. O., Krusche, A. V., Ballester, M. V. R., and Richey, J. E.: Methane emissions from Amazonian Rivers and their contribution to the global methane budget, Glob. Change Biol., 20, 2829–2840, https://doi.org/10.1111/gcb.12646, 2014.
Schlünz, B. and Schneider, R. R.: Transport of organic carbon to the oceans by rivers: reestimating flux and burial rates, Int. J. Earth Sci., 88, 599–606, 2000.
Tamooh, F., Van den Meersche, K., Meysman, F., Marwick, T. R., Borges, A. V., Merckx, R., Dehairs, F., Schmidt, S., Nyunja, J., and Bouillon, S.: Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya, Biogeosciences, 9, 2905–2920, https://doi.org/10.5194/bg-9-2905-2012, 2012.
Tamooh, F., Borges, A. V., Meysman, F. J. R., Van Den Meersche, K., Dehairs, F., Merckx, R., and Bouillon, S.: Dynamics of dissolved inorganic carbon and aquatic metabolism in the Tana River basin, Kenya, Biogeosciences, 10, 6911–6928, https://doi.org/10.5194/bg-10-6911-2013, 2013.
Teodoru, C. R., del Giorgio, P., Prairie, Y. T., and Camire, M.: pCO2 dynamics in boreal streams of northern Quebec, Canada, Global Biogeochem. Cy., 23, GB2012, https://doi.org/10.1029/2008GB003404, 2009.
Teodoru, C. R., del Giorgio, P., and Prairie, Y. T.: Spatial heterogeneity of surface CO2 fluxes in a newly created Eastmain-1 reservoir in northern Quebec, Canada, Ecosystems, 14, 28–46, https://doi.org/10.1007/s10021-010-9393-7, 2010.
Tranvik, L. J., Downing, J. A., Cotner, J. B., Loiselle, S. A., Striegl, R. G., Ballatore, T. J., Dillon, P., Finlay, K., Knoll, L. B., Kortelainen, P. L., Kutser, T., Larsen, S., Laurion, I., Leech, D. M., McCallister, L. S., McKnight, D. M., Melack, J. M., Porter, J. A., Prairie, Y. T., Renwick, W. H., Roland, F., Sherman, B. S., Schindler, D. W., Sobeck, S., Tremblay, A., Vanni, M. J., Verschoor, A. M., von Wachenfelds, E., and Weyhenmeyer, G. A.: Lakes and reservoirs as regulators of carbon cycling and climate, Limnol. Oceanogr., 54, 2298–2314, https://doi.org/10.4319/lo.2009.54.6_part_2.2298, 2009.
Waldron, S., Scott, E. M., and Soulsby, C.: Stable isotope analysis reveals lower-order river dissolved inorganic carbon pools are highly dynamic, Environ. Sci. Technol., 41, 6156–6162, https://doi.org/10.1021/es0706089, 2007.
Wang, Z. A., Bienvenu, D. J., Mann, P. J., Hoering, K. A., Poulsen, J. R., Spencer, R. G. M., and Holmes, R. M.: Inorganic carbon speciation and fluxes in the Congo River, Geophys. Res. Lett., 40, 511–516, https://doi.org/10.1002/grl.50160, 2013.
Weiss, F. R. and Price, B. A.: Nitrous oxide solubility in water and seawater, Mar. Chem., 8, 347–359, 1980.
Weiss, R. F.: Determinations of carbon dioxide and methane by dual catalyst flame ionization chromatography and nitrous oxide by electron capture chromatography, J. Chromatogr. Sci., 19, 611–616, 1981.
Wellington, J. H.: Southern Africa – a Geographic Study, vol. 1, Physical Geography, Cambridge University Press, Cambridge, 528 pp., 1955.
Whitfield, P. H., Aherne, J., and Watmough, S.: Predicting the partial pressure of carbon dioxide in boreal lakes, Can. Water Resour. J., 34, 415–426, 2009.
World Bank.: The Zambezi River Basin, A multi-sector investment opportunities analysis, vol. 3: State of the basin, published by the International Bank for Reconstruction and Development/The World Bank, 1818 H Street NW, Washington DC 20433, USA, 202 pp., 2010.
Worrall, F., Burt, T., and Adamson, J.: Fluxes of dissolved carbon dioxide and inorganic carbon from an upland peat catchment: implications for soil respiration, Biogeochemistry, 73, 515–539, https://doi.org/10.1007/s10533-004-1717-2, 2005.
Yamamoto, S., Alcauskas, J. B., and Crozier, T. E.: Solubility of methane in distilled water and seawater, J. Chem. Eng. Data, 21, 78–80, 1976.
Zurbrügg, R., Wamulume, J., Kamanga, R., Wehrli, B., and Senn, D. B.: River-floodplain exchange and its effects on the fluvial oxygen regime in a large tropical river system (Kafue Flats, Zambia), J. Geophys. Res., 117, G03008, https://doi.org/10.1029/2011JG001853, 2012.
Short summary
CO2 and CH4 concentrations and fluxes in the Zambezi River basin are well below the median/average values reported previously for tropical rivers, streams and reservoirs, and mainly controlled by the connectivity with floodplains and the presence of waterfalls and man-made reservoirs. The mass balance suggests that carbon transport to the ocean represents the major component (~60%) of the budget, while emissions to the atmosphere account for less than 40% of the total carbon yield.
CO2 and CH4 concentrations and fluxes in the Zambezi River basin are well below the...
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