Articles | Volume 18, issue 1
14 Jan 2021
Research article | 14 Jan 2021
Estimating immediate post-fire carbon fluxes using the eddy-covariance technique
Bruna R. F. Oliveira et al.
Bruna R. F. Oliveira, Jan J. Keizer, and Thomas Foken
Biogeosciences, 19, 2235–2243,Short summary
This study analyzes the impacts of this windthrow on the aerodynamic characteristics of zero-plane displacement and roughness length and, ultimately, their implications for the turbulent fluxes. The turbulent fluxes were only affected to a minor degree by the windthrow, but the footprint area of the flux tower changed markedly so that the target area of the measurements had to be redetermined.
Bruna R. F. Oliveira, Jan J. Keizer, and Thomas Foken
Biogeosciences, 19, 2235–2243,Short summary
This study analyzes the impacts of this windthrow on the aerodynamic characteristics of zero-plane displacement and roughness length and, ultimately, their implications for the turbulent fluxes. The turbulent fluxes were only affected to a minor degree by the windthrow, but the footprint area of the flux tower changed markedly so that the target area of the measurements had to be redetermined.
Katharina Jentzsch, Julia Boike, and Thomas Foken
Atmos. Meas. Tech., 14, 7291–7296,Short summary
Very small CO2 fluxes are measured at night in Arctic regions. If the sensible heat flux is not close to zero under these conditions, the WPL correction will take values on the order of the flux. A special quality control is proposed for these cases.
Mathias Göckede, Fanny Kittler, and Carsten Schaller
Biogeosciences, 16, 3113–3131,Short summary
Methane is one of the most important greenhouse gases. Methane emissions from land sources to the atmosphere often occur in the form of short but intense outbursts, which are difficult to measure. We developed a new software tool based on wavelets which reliably quantifies such methane outbursts. Using these results as a reference, our study shows that regular data processing using the eddy-covariance technique provides solid long-term methane budgets, but short-term uncertainties can be high.
Carsten Schaller, Fanny Kittler, Thomas Foken, and Mathias Göckede
Atmos. Chem. Phys., 19, 4041–4059,Short summary
Methane emissions from biogenic sources, e.g. Arctic permafrost ecosystems, are associated with uncertainties due to the high variability of fluxes in both space and time. Besides the traditional eddy covariance method, we evaluated a method based on wavelet analysis, which does not require a stationary time series, to calculate fluxes. The occurrence of extreme methane flux events was strongly correlated with the soil temperature. They were triggered by atmospheric non-turbulent mixing.
Thomas Foken, Wolfgang Babel, and Christoph Thomas
Atmos. Meas. Tech., 12, 971–976,Short summary
Recently reported trends of carbon dioxide uptake pose the question of whether trends may be the result of the limited digitalization of gas analysers and sonic anemometers used in the 1990s. Modifying a 12 bit digitalization and the instrument error reported for the R2 and R3 sonic anemometers found elsewhere, the influence of these deficits in comparison to the now commonly used 16 bit digitalization were quantified. Both issues have an effect only on trace gas fluxes of small magnitude.
Kathrin Gatzsche, Wolfgang Babel, Eva Falge, Rex David Pyles, Kyaw Tha Paw U, Armin Raabe, and Thomas Foken
Biogeosciences, 15, 2945–2960,Short summary
The ecosystem is a significant sink of carbon dioxide. To quantify this sink, very complex and validated models are required. However, the comparison of modeled and measured energy and matter fluxes in a heterogeneous landscape is still a challenge. On the one hand, models must be applied for various surface types, while on the other hand the comparison of the fluxes is only possible based on the flux source areas. This paper treats the potential aggregation of modeled fluxes and its validation.
Carsten Schaller, Mathias Göckede, and Thomas Foken
Atmos. Meas. Tech., 10, 869–880,Short summary
The eddy covariance (EC) method allows for measuring and calculating vertical turbulent exchange fluxes between ecosystems and the atmosphere. It fails in non-steady-state flow conditions, e.g. in Arctic regions. Two alternative calculation methods, conditional sampling and wavelet analysis, were implemented and compared to EC. Wavelet analysis for allows calculating a trustworthy flux even in non-stationary times and offers new possibilities for exact flux calculation in difficult environments.
Yiying Chen, James Ryder, Vladislav Bastrikov, Matthew J. McGrath, Kim Naudts, Juliane Otto, Catherine Ottlé, Philippe Peylin, Jan Polcher, Aude Valade, Andrew Black, Jan A. Elbers, Eddy Moors, Thomas Foken, Eva van Gorsel, Vanessa Haverd, Bernard Heinesch, Frank Tiedemann, Alexander Knohl, Samuli Launiainen, Denis Loustau, Jérôme Ogée, Timo Vessala, and Sebastiaan Luyssaert
Geosci. Model Dev., 9, 2951–2972,Short summary
In this study, we compiled a set of within-canopy and above-canopy measurements of energy and water fluxes, and used these data to parametrize and validate the new multi-layer energy budget scheme for a range of forest types. An adequate parametrization approach has been presented for the global-scale land surface model (ORCHIDEE-CAN). Furthermore, model performance of the new multi-layer parametrization was compared against the existing single-layer scheme.
T. Gerken, W. Babel, M. Herzog, K. Fuchs, F. Sun, Y. Ma, T. Foken, and H.-F. Graf
Hydrol. Earth Syst. Sci., 19, 4023–4040,Short summary
Surface moisture is an important control for the development of clouds and precipitation on the Tibetan Plateau. While dry surface conditions do not provided enough water for the development of precipitation and convection, wet surface conditions lead to increased cloud cover and a decrease in solar irradiation, which also reduces convection development. It was found that intermediate soil moistures are associated with the strongest convection.
J. J. Keizer, M. A. S. Martins, S. A. Prats, L. F. Santos, D. C. S. Vieira, R. Nogueira, and L. Bilro
SOIL, 1, 641–650,Short summary
In this study, a novel plastic optical fibre turbidity sensor was exhaustively tested with a large set of runoff samples, mainly from a recently burnt area. The different types of samples from the distinct study sites revealed without exception an increase in normalized light loss with increasing sediment concentrations that agreed (reasonably) well with a power function. Nevertheless, sensor-based predictions of sediment concentration should ideally involve site-specific calibrations.
D. Hawtree, J. P. Nunes, J. J. Keizer, R. Jacinto, J. Santos, M. E. Rial-Rivas, A.-K. Boulet, F. Tavares-Wahren, and K.-H. Feger
Hydrol. Earth Syst. Sci., 19, 3033–3045,
A. Moravek, P. Stella, T. Foken, and I. Trebs
Atmos. Chem. Phys., 15, 899–911,
M. Riederer, J. Hübner, J. Ruppert, W. A. Brand, and T. Foken
Atmos. Meas. Tech., 7, 4237–4250,Short summary
The REA technique cannot be applied on grassland shortly after management without the risk of REA-flux errors due to large uncertainties of b-factors and lacking scalar similarity. The NEE flux partitioning model based on REA measurement results is complex but can enhance results of common partitioning by considering ecosystem discrimination of 13C and wind velocity.
W. Babel, T. Biermann, H. Coners, E. Falge, E. Seeber, J. Ingrisch, P.-M. Schleuß, T. Gerken, J. Leonbacher, T. Leipold, S. Willinghöfer, K. Schützenmeister, O. Shibistova, L. Becker, S. Hafner, S. Spielvogel, X. Li, X. Xu, Y. Sun, L. Zhang, Y. Yang, Y. Ma, K. Wesche, H.-F. Graf, C. Leuschner, G. Guggenberger, Y. Kuzyakov, G. Miehe, and T. Foken
Biogeosciences, 11, 6633–6656,
J. Hübner, J. Olesch, H. Falke, F. X. Meixner, and T. Foken
Atmos. Meas. Tech., 7, 2967–2980,
A. Moravek, T. Foken, and I. Trebs
Atmos. Meas. Tech., 7, 2097–2119,
M. Riederer, A. Serafimovich, and T. Foken
Atmos. Meas. Tech., 7, 1057–1064,
S. C. Pereira, A. C. Carvalho, J. Ferreira, J. P. Nunes, J. J. Keizer, and A. Rocha
Hydrol. Earth Syst. Sci., 17, 3741–3758,
P. Stella, M. Kortner, C. Ammann, T. Foken, F. X. Meixner, and I. Trebs
Biogeosciences, 10, 5997–6017,
S. Metzger, W. Junkermann, M. Mauder, K. Butterbach-Bahl, B. Trancón y Widemann, F. Neidl, K. Schäfer, S. Wieneke, X. H. Zheng, H. P. Schmid, and T. Foken
Biogeosciences, 10, 2193–2217,
M. Li, W. Babel, K. Tanaka, and T. Foken
Atmos. Meas. Tech., 6, 221–229,
Related subject area
Biogeochemistry: Greenhouse GasesExcess soil moisture and fresh carbon input are prerequisites for methane production in podzolic soilLow biodegradability of particulate organic carbon mobilized from thaw slumps on the Peel Plateau, NT, and possible chemosynthesis and sorption effectsGrazing enhances carbon cycling but reduces methane emission during peak growing season in the Siberian Pleistocene Park tundra siteIdeas and perspectives: Enhancing research and monitoring of carbon pools and land-to-atmosphere greenhouse gases exchange in developing countriesIgnoring carbon emissions from thermokarst ponds results in overestimation of tundra net carbon uptakeQuantification of potential methane emissions associated with organic matter amendments following oxic-soil inundationAssessing the spatial and temporal variability of greenhouse gas emissions from different configurations of on-site wastewater treatment system using discrete and continuous gas flux measurementDimethylated sulfur compounds in the Peruvian upwelling systemPartitioning carbon sources between wetland and well-drained ecosystems to a tropical first-order stream – implications for carbon cycling at the watershed scale (Nyong, Cameroon)Extreme events driving year-to-year differences in gross primary productivity across the USEvaluating alternative ebullition models for predicting peatland methane emission and its pathways via data-model fusionMethane gas emissions from savanna fires: what analysis of local burning regimes in a working West African landscape tell usMethane in Zackenberg Valley, NE Greenland: multidecadal growing season fluxes of a high-Arctic tundraResponse of vegetation and carbon fluxes to brown lemming herbivory in Northern AlaskaField-scale CH4 emission at a subarctic mire with heterogeneous permafrost thaw statusEvaluation of denitrification and decomposition from three biogeochemical models using laboratory measurements of N2, N2O and CO2Temporal trends in methane emissions from a small eutrophic reservoir: the key role of a spring burstGreenhouse gases emissions from riparian wetlands: an example from the Inner Mongolia grassland region in ChinaSources of nitrous oxide and fate of mineral nitrogen in sub-Arctic permafrost peat soilsVariability of North Atlantic CO2 fluxes for the 2000–2017 period estimated from atmospheric inverse analysesEffects of clear-fell harvesting on soil CO2, CH4, and N2O fluxes in an upland Sitka spruce stand in EnglandConventional subsoil irrigation techniques do not lower carbon emissions from drained peat meadowsDifferent responses of ecosystem CO2 and N2O emissions and CH4 uptake to seasonally asymmetric warming in an alpine grassland of the TianshanThe role of termite CH4 emissions on the ecosystem scale: a case study in the Amazon rainforestBiogeochemical and plant trait mechanisms drive enhanced methane emissions in response to whole-ecosystem warmingA decade of dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO) measurements in the southwestern Baltic SeaMethane dynamics in three different Siberian water bodies under winter and summer conditionsTopography-based statistical modelling reveals high spatial variability and seasonal emission patches in forest floor methane fluxTechnical note: CO2 is not like CH4 – limits of and corrections to the headspace method to analyse pCO2 in fresh waterComparison of greenhouse gas fluxes from tropical forests and oil palm plantations on mineral soilAre there memory effects on greenhouse gas emissions (CO2, N2O and CH4) following grassland restoration?Intraseasonal variability of greenhouse gas emission factors from biomass burning in the Brazilian CerradoEvaluating stream CO2 outgassing via drifting and anchored flux chambers in a controlled flume experimentCarbon dioxide and methane exchange of a patterned subarctic fen during two contrasting growing seasonsUsing satellite data to identify the methane emission controls of South Sudan's wetlandsIdeas and perspectives: patterns of soil CO2, CH4, and N2O fluxes along an altitudinal gradient – a pilot study from an Ecuadorian neotropical montane forestWater flow controls the spatial variability of methane emissions in a northern valley fen ecosystemSeasonality, drivers, and isotopic composition of soil CO2 fluxes from tropical forests of the Congo BasinSpatially resolved evaluation of Earth system models with satellite column-averaged CO2Ideas and perspectives: A strategic assessment of methane and nitrous oxide measurements in the marine environmentStem and soil nitrous oxide fluxes from rainforest and cacao agroforest on highly weathered soils in the Congo BasinMethane paradox in tropical lakes? Sedimentary fluxes rather than pelagic production in oxic conditions sustain methanotrophy and emissions to the atmosphereOrganic matter and sediment properties determine in-lake variability of sediment CO2 and CH4 production and emissions of a small and shallow lakeMineralization of organic matter in boreal lake sediments: rates, pathways, and nature of the fermenting substratesTechnical note: Facilitating the use of low-cost methane (CH4) sensors in flux chambers – calibration, data processing, and an open-source make-it-yourself loggerN2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactionsCarbon dioxide and methane fluxes from different surface types in a created urban wetlandA decade of methane measurements at the Boknis Eck Time Series Station in Eckernförde Bay (southwestern Baltic Sea)Dissolved CH4 coupled to photosynthetic picoeukaryotes in oxic waters and to cumulative chlorophyll a in anoxic waters of reservoirsCarbon dioxide dynamics in an agricultural headwater stream driven by hydrology and primary production
Mika Korkiakoski, Tiia Määttä, Krista Peltoniemi, Timo Penttilä, and Annalea Lohila
Biogeosciences, 19, 2025–2041,Short summary
We measured CH4 fluxes and production and oxidation potentials from irrigated and non-irrigated podzolic soil in a boreal forest. CH4 sink was smaller at the irrigated site but did not cause CH4 emission, with one exception. We also showed that under laboratory conditions, not only wet conditions, but also fresh carbon, are needed to make podzolic soil into a CH4 source. Our study provides important data for improving the process models describing the upland soil CH4 dynamics.
Sarah Shakil, Suzanne E. Tank, Jorien E. Vonk, and Scott Zolkos
Biogeosciences, 19, 1871–1890,Short summary
Permafrost thaw-driven landslides in the western Arctic are increasing organic carbon delivered to headwaters of drainage networks in the western Canadian Arctic by orders of magnitude. Through a series of laboratory experiments, we show that less than 10 % of this organic carbon is likely to be mineralized to greenhouse gases during transport in these networks. Rather most of the organic carbon is likely destined for burial and sequestration for centuries to millennia.
Wolfgang Fischer, Christoph K. Thomas, Nikita Zimov, and Mathias Göckede
Biogeosciences, 19, 1611–1633,Short summary
Arctic permafrost ecosystems may release large amounts of carbon under warmer future climates and may therefore accelerate global climate change. Our study investigated how long-term grazing by large animals influenced ecosystem characteristics and carbon budgets at a Siberian permafrost site. Our results demonstrate that such management can contribute to stabilizing ecosystems to keep carbon in the ground, particularly through drying soils and reducing methane emissions.
Dong-Gill Kim, Ben Bond-Lamberty, Youngryel Ryu, Bumsuk Seo, and Dario Papale
Biogeosciences, 19, 1435–1450,Short summary
As carbon (C) and greenhouse gas (GHG) research has adopted appropriate technology and approach (AT&A), low-cost instruments, open-source software, and participatory research and their results were well accepted by scientific communities. In terms of cost, feasibility, and performance, the integration of low-cost and low-technology, participatory and networking-based research approaches can be AT&A for enhancing C and GHG research in developing countries.
Lutz Beckebanze, Zoé Rehder, David Holl, Christian Wille, Charlotta Mirbach, and Lars Kutzbach
Biogeosciences, 19, 1225–1244,Short summary
Arctic permafrost landscapes feature many water bodies. In contrast to the terrestrial parts of the landscape, the water bodies release carbon to the atmosphere. We compare carbon dioxide and methane fluxes from small water bodies to the surrounding tundra and find not accounting for the carbon dioxide emissions leads to an overestimation of the tundra uptake by 11 %. Consequently, changes in hydrology and water body distribution may substantially impact the overall carbon budget of the Arctic.
Brian Scott, Andrew H. Baldwin, and Stephanie A. Yarwood
Biogeosciences, 19, 1151–1164,Short summary
Carbon dioxide and methane contribute to global warming. What can we do? We can build wetlands: they store carbon dioxide and should cause global cooling. But when first built they produce excess methane. Eventually built wetlands will cause cooling, but it may take decades or even centuries. How we build wetlands matters. We show that a common practice, using organic matter, such as manure, can make a big difference whether or not the wetlands we build start global cooling within our lifetime.
Jan Knappe, Celia Somlai, and Laurence W. Gill
Biogeosciences, 19, 1067–1085,Short summary
Two domestic on-site wastewater treatment systems have been monitored for greenhouse gas (carbon dioxide, methane and nitrous oxide) emissions coming from the process units, soil and vent pipes. This has enabled the net greenhouse gas per person to be quantified for the first time, as well as the impact of pre-treatment on the effluent before being discharged to soil. These decentralised wastewater treatment systems serve approx. 20 % of the population in both Europe and the United States.
Yanan Zhao, Dennis Booge, Christa A. Marandino, Cathleen Schlundt, Astrid Bracher, Elliot L. Atlas, Jonathan Williams, and Hermann W. Bange
Biogeosciences, 19, 701–714,Short summary
We present here, for the first time, simultaneously measured dimethylsulfide (DMS) seawater concentrations and DMS atmospheric mole fractions from the Peruvian upwelling region during two cruises in December 2012 and October 2015. Our results indicate low oceanic DMS concentrations and atmospheric DMS molar fractions in surface waters and the atmosphere, respectively. In addition, the Peruvian upwelling region was identified as an insignificant source of DMS emissions during both periods.
Moussa Moustapha, Loris Deirmendjian, David Sebag, Jean-Jacques Braun, Stéphane Audry, Henriette Ateba Bessa, Thierry Adatte, Carole Causserand, Ibrahima Adamou, Benjamin Ngounou Ngatcha, and Frédéric Guérin
Biogeosciences, 19, 137–163,Short summary
We monitor the spatio-temporal variability of organic and inorganic carbon (C) species in the tropical Nyong River (Cameroon), across groundwater and increasing stream orders. We show the significant contribution of wetland as a C source for tropical rivers. Thus, ignoring the river–wetland connectivity might lead to the misrepresentation of C dynamics in tropical watersheds. Finally, total fluvial carbon losses might offset ~10 % of the net C sink estimated for the whole Nyong watershed.
Alexander J. Turner, Philipp Köhler, Troy S. Magney, Christian Frankenberg, Inez Fung, and Ronald C. Cohen
Biogeosciences, 18, 6579–6588,Short summary
This work builds a high-resolution estimate (500 m) of gross primary productivity (GPP) over the US using satellite measurements of solar-induced chlorophyll fluorescence (SIF) from the TROPOspheric Monitoring Instrument (TROPOMI) between 2018 and 2020. We identify ecosystem-specific scaling factors for estimating gross primary productivity (GPP) from TROPOMI SIF. Extreme precipitation events drive four regional GPP anomalies that account for 28 % of year-to-year GPP differences across the US.
Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, and Yiqi Luo
Revised manuscript accepted for BGShort summary
The relative ratio of wetland methane (CH4) emission pathways determines how much CH4 is oxidized before leaving the soil. We found an ebullition modeling approach that has a better performance in deep layer pore water CH4 concentration. We suggest using this approach in Land Surface Models to accurately represent CH4 emission dynamics and its response to climate change. Our results also highlight that both CH4 flux and belowground concentration data are important to constrain model parameters.
Paul Laris, Moussa Koné, Fadiala Dembélé, Christine M. Rodrigue, Lilian Yang, Rebecca Jacobs, and Quincy Laris
Biogeosciences, 18, 6229–6244,Short summary
Savanna fires play a key role in the global carbon cycle because they release methane. Although it burns the most, there are few studies from West Africa. We conducted 36 experimental fires according to local practice to collect smoke samples. We found that fires set early in the season had higher methane emissions than those set later, and head fires had double the emissions of backfires. We conclude policies to reduce emissions will not have the desired effects if fire type is not considered.
Johan H. Scheller, Mikhail Mastepanov, Hanne H. Christiansen, and Torben R. Christensen
Biogeosciences, 18, 6093–6114,Short summary
Our study presents a time series of methane emissions in a high-Arctic-tundra landscape over 14 summers, which shows large variations between years. The methane emissions from the valley are expected to more than double in the late 21st century. This warming increases permafrost thaw, which could increase surface erosion in the valley. Increased erosion could offset some of the rise in methane fluxes from the valley, but this would require large-scale impacts on vegetated surfaces.
Jessica Plein, Rulon W. Clark, Kyle A. Arndt, Walter C. Oechel, Douglas Stow, and Donatella Zona
Preprint under review for BGShort summary
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 impacted carbon exchange of tundra ecosystems via altering carbon dioxide (CO2) and methane (CH4) fluxes. Lemmings significantly decreased CO2 uptake, while not affecting CH4 emissions. There was no significant difference the following growing season due to recovery of the vegetation.
Patryk Łakomiec, Jutta Holst, Thomas Friborg, Patrick Crill, Niklas Rakos, Natascha Kljun, Per-Ola Olsson, Lars Eklundh, Andreas Persson, and Janne Rinne
Biogeosciences, 18, 5811–5830,Short summary
Methane emission from the subarctic mire with heterogeneous permafrost status was measured for the years 2014–2016. Lower methane emission was measured from the palsa mire sector while the thawing wet sector emitted more. Both sectors have a similar annual pattern with a gentle rise during spring and a decrease during autumn. The highest emission was observed in the late summer. Winter emissions were positive during the measurement period and have a significant impact on the annual budgets.
Balázs Grosz, Reinhard Well, Rene Dechow, Jan Reent Köster, Mohammad Ibrahim Khalil, Simone Merl, Andreas Rode, Bianca Ziehmer, Amanda Matson, and Hongxing He
Biogeosciences, 18, 5681–5697,Short summary
To assure quality predictions biogeochemical models must be current. We use data measured using novel incubation methods to test the denitrification sub-modules of three models. We aim to identify limitations in the denitrification modeling to inform next steps for development. Several areas are identified, most urgently improved denitrification control parameters and further testing with high-temporal-resolution datasets. Addressing these would significantly improve denitrification modeling.
Sarah Waldo, Jake J. Beaulieu, William Barnett, D. Adam Balz, Michael J. Vanni, Tanner Williamson, and John T. Walker
Biogeosciences, 18, 5291–5311,Short summary
Human-made reservoirs impact the carbon cycle. In particular, the breakdown of organic matter in reservoir sediments can result in large emissions of greenhouse gases (especially methane) to the atmosphere. This study takes an intensive look at the patterns in greenhouse gas emissions from a single reservoir in Ohio (United States) and the role of water temperature, precipitation, and algal blooms in emissions. We saw a "spring burst" of elevated emissions that challenged our assumptions.
Xinyu Liu, Xixi Lu, Ruihong Yu, Heyang Sun, Hao Xue, Zhen Qi, Zhengxu Cao, Zhuangzhuang Zhang, and Tingxi Liu
Biogeosciences, 18, 4855–4872,Short summary
Gradual riparian wetland drying is increasingly sensitive to global warming and contributes to climate change. We analyzed the emissions of CO2, CH4, and N2O from riparian wetlands in the Xilin River basin to understand the role of these ecosystems in greenhouse gas emissions. Our study showed that anthropogenic activities have extensively changed the hydrological characteristics of the riparian wetlands and might accelerate carbon loss, which could further affect greenhouse gas emissions.
Jenie A. Gil, Maija E. Marushchak, Tobias Rütting, Elizabeth M. Baggs, Tibisay Pérez, Alexander Novakovskiy, Tatiana Trubnikova, Dmitry Kaverin, Pertti J. Martikainen, and Christina Biasi
Revised manuscript accepted for BGShort summary
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 soils 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.
Zhaohui Chen, Parvadha Suntharalingam, Andrew J. Watson, Ute Schuster, Jiang Zhu, and Ning Zeng
Biogeosciences, 18, 4549–4570,Short summary
As the global temperature continues to increase, carbon dioxide (CO2) is a major driver of this global warming. The increased CO2 is mainly caused by emissions from fossil fuel use and land use. At the same time, the ocean is a significant sink in the carbon cycle. The North Atlantic is a critical ocean region in reducing CO2 concentration. We estimate the CO2 uptake in this region based on a carbon inverse system and atmospheric CO2 observations.
Sirwan Yamulki, Jack Forster, Georgios Xenakis, Adam Ash, Jacqui Brunt, Mike Perks, and James I. L. Morison
Biogeosciences, 18, 4227–4241,Short summary
The effect of clear-felling on soil greenhouse gas (GHG) fluxes was assessed in a Sitka spruce forest. Measurements over 4 years showed that CO2, CH4, and N2O fluxes responded differently to clear-felling due to significant changes in soil biotic and abiotic factors and showed large variations between years. Over 3 years since felling, the soil GHG flux was reduced by 45% due to a much larger reduction in CO2 efflux than increases in N2O (up to 20%) and CH4 (changed from sink to source) fluxes.
Stefan Theodorus Johannes Weideveld, Weier Liu, Merit van den Berg, Leon Peter Maria Lamers, and Christian Fritz
Biogeosciences, 18, 3881–3902,Short summary
Raising the groundwater table (GWT) trough subsoil irrigation does not lead to a reduction of carbon emissions from drained peat meadows, even though there was a clear increase in the GWT during summer. Most likely, the largest part of the peat oxidation takes place in the top 70 cm of the soil, which stays above the GWT with the use of subsoil irrigation. We conclude that the use of subsoil irrigation is ineffective as a mitigation measure to sufficiently lower peat oxidation rates.
Yanming Gong, Ping Yue, Kaihui Li, Anwar Mohammat, and Yanyan Liu
Biogeosciences, 18, 3529–3537,Short summary
At present, data on the influence of asymmetric warming on the GHG flux on a temporal scale are scarce. GHG fluxes were measured using static chambers and a gas chromatograph. Our study showed that the effect of seasonally asymmetrical warming on CO2 flux was obvious, with the GHG flux being able to adapt to continuous warming. Warming in the non-growing season increased the temperature dependence of GHG flux.
Hella van Asperen, João Rafael Alves-Oliveira, Thorsten Warneke, Bruce Forsberg, Alessandro Carioca de Araújo, and Justus Notholt
Biogeosciences, 18, 2609–2625,Short summary
Termites are insects that are highly abundant in tropical ecosystems. It is known that termites emit CH4, an important greenhouse gas, but their absolute emission remains uncertain. In the Amazon rainforest, we measured CH4 emissions from termite nests and groups of termites. In addition, we tested a fast and non-destructive field method to estimate termite nest colony size. We found that termites play a significant role in an ecosystem's CH4 budget and probably emit more than currently assumed.
Genevieve L. Noyce and J. Patrick Megonigal
Biogeosciences, 18, 2449–2463,Short summary
Methane (CH4) is a potent greenhouse gas that contributes to global radiative forcing. A mechanistic understanding of how wetland CH4 cycling will respond to global warming is crucial for improving prognostic models. We present results from the first 4 years of a novel whole-ecosystem warming experiment in a coastal wetland, showing that warming increases CH4 emissions and identifying four potential mechanisms that can be added to future modeling efforts.
Yanan Zhao, Cathleen Schlundt, Dennis Booge, and Hermann W. Bange
Biogeosciences, 18, 2161–2179,Short summary
We present a unique and comprehensive time-series study of biogenic sulfur compounds in the southwestern Baltic Sea, from 2009 to 2018. Dimethyl sulfide is one of the key players regulating global climate change, as well as dimethylsulfoniopropionate and dimethyl sulfoxide. Their decadal trends did not follow increasing temperature but followed some algae group abundances at the Boknis Eck Time Series Station.
Ingeborg Bussmann, Irina Fedorova, Bennet Juhls, Pier Paul Overduin, and Matthias Winkel
Biogeosciences, 18, 2047–2061,Short summary
Arctic rivers, lakes, and bays are affected by a warming climate. We measured the amount and consumption of methane in waters from Siberia under ice cover and in open water. In the lake, methane concentrations under ice cover were much higher than in summer, and methane consumption was highest. The ice cover leads to higher methane concentration under ice. In a warmer Arctic, there will be more time with open water when methane is consumed by bacteria, and less methane will escape into the air.
Elisa Vainio, Olli Peltola, Ville Kasurinen, Antti-Jussi Kieloaho, Eeva-Stiina Tuittila, and Mari Pihlatie
Biogeosciences, 18, 2003–2025,Short summary
We studied forest floor methane exchange over an area of 10 ha in a boreal pine forest. The results demonstrate high spatial variability in soil moisture and consequently in the methane flux. We detected wet patches emitting high amounts of methane in the early summer; however, these patches turned to methane uptake in the autumn. We concluded that the small-scale spatial variability of the boreal forest methane flux highlights the importance of soil chamber placement in similar studies.
Matthias Koschorreck, Yves T. Prairie, Jihyeon Kim, and Rafael Marcé
Biogeosciences, 18, 1619–1627,Short summary
The concentration of carbon dioxide (CO2) in water samples is often measured using a gas chromatograph. Depending on the chemical composition of the water, this method can produce wrong results. We quantified the possible error and how it depends on water composition and the analytical procedure. We propose a method to correct wrong results by additionally analysing alkalinity in the samples. We provide an easily usable computer code to perform the correction calculations.
Julia Drewer, Melissa M. Leduning, Robert I. Griffiths, Tim Goodall, Peter E. Levy, Nicholas Cowan, Edward Comynn-Platt, Garry Hayman, Justin Sentian, Noreen Majalap, and Ute M. Skiba
Biogeosciences, 18, 1559–1575,Short summary
In Southeast Asia, oil palm plantations have largely replaced tropical forests. The impact of this shift in land use on greenhouse gas fluxes and soil microbial communities remains uncertain. We have found emission rates of the potent greenhouse gas nitrous oxide on mineral soil to be higher from oil palm plantations than logged forest over a 2-year study and concluded that emissions have increased over the last 42 years in Sabah, with the proportion of emissions from plantations increasing.
Lutz Merbold, Charlotte Decock, Werner Eugster, Kathrin Fuchs, Benjamin Wolf, Nina Buchmann, and Lukas Hörtnagl
Biogeosciences, 18, 1481–1498,Short summary
Our study investigated the exchange of the three major greenhouse gases (GHGs) over a temperate grassland prior to and after restoration through tillage in central Switzerland. Our results show that irregular management events, such as tillage, have considerable effects on GHG emissions in the year of tillage while leading to enhanced carbon uptake and similar nitrogen losses via nitrous oxide in the years following tillage to those observed prior to tillage.
Roland Vernooij, Marcos Giongo, Marco Assis Borges, Máximo Menezes Costa, Ana Carolina Sena Barradas, and Guido R. van der Werf
Biogeosciences, 18, 1375–1393,Short summary
We used drones to measure greenhouse gas emission factors from fires in the Brazilian Cerrado. We compared early-dry-season management fires and late-dry-season fires to determine if fire management can be a tool for abating emissions. Although we found some evidence of increased CO and CH4 emission factors, the seasonal effect was smaller than that found in previous studies. For N2O, the third most important greenhouse gas, we found opposite trends in grass- and shrub-dominated areas.
Filippo Vingiani, Nicola Durighetto, Marcus Klaus, Jakob Schelker, Thierry Labasque, and Gianluca Botter
Biogeosciences, 18, 1223–1240,Short summary
Flexible foil chamber design and the anchored deployment might be useful techniques to enhance the robustness and the accuracy of CO2 measurements in low-order streams. Moreover, the study demonstrates the value of analytical and numerical techniques for the estimation of gas exchange velocities. These results may contribute to the development of novel procedures for chamber data analysis which might improve the robustness and reliability of chamber-based CO2 measurements in first-order streams.
Lauri Heiskanen, Juha-Pekka Tuovinen, Aleksi Räsänen, Tarmo Virtanen, Sari Juutinen, Annalea Lohila, Timo Penttilä, Maiju Linkosalmi, Juha Mikola, Tuomas Laurila, and Mika Aurela
Biogeosciences, 18, 873–896,Short summary
We studied ecosystem- and plant-community-level carbon (C) exchange between subarctic mire and the atmosphere during 2017–2018. We found strong spatial variation in CO2 and CH4 dynamics between the main plant communities. The earlier onset of growing season in 2018 strengthened the CO2 sink of the ecosystem, but this gain was counterbalanced by a later drought period. Variation in water table level, soil temperature and vegetation explained most of the variation in ecosystem-level C exchange.
Sudhanshu Pandey, Sander Houweling, Alba Lorente, Tobias Borsdorff, Maria Tsivlidou, A. Anthony Bloom, Benjamin Poulter, Zhen Zhang, and Ilse Aben
Biogeosciences, 18, 557–572,Short summary
We use atmospheric methane observations from the novel TROPOspheric Monitoring Instrument (TROPOMI; Sentinel-5p) to estimate methane emissions from South Sudan's wetlands. Our emission estimates are an order of magnitude larger than the estimate of process-based wetland models. We find that this underestimation by the models is likely due to their misrepresentation of the wetlands' inundation extent and temperature dependences.
Paula Alejandra Lamprea Pineda, Marijn Bauters, Hans Verbeeck, Selene Baez, Matti Barthel, Samuel Bodé, and Pascal Boeckx
Biogeosciences, 18, 413–421,Short summary
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.
Hui Zhang, Eeva-Stiina Tuittila, Aino Korrensalo, Aleksi Räsänen, Tarmo Virtanen, Mika Aurela, Timo Penttilä, Tuomas Laurila, Stephanie Gerin, Viivi Lindholm, and Annalea Lohila
Biogeosciences, 17, 6247–6270,Short summary
We studied the impact of a stream on peatland microhabitats and CH4 emissions in a northern boreal fen. We found that there were higher water levels, lower peat temperatures, and greater oxygen concentrations close to the stream; these supported the highest biomass production but resulted in the lowest CH4 emissions. Further from the stream, the conditions were drier and CH4 emissions were also low. CH4 emissions were highest at an intermediate distance from the stream.
Simon Baumgartner, Matti Barthel, Travis William Drake, Marijn Bauters, Isaac Ahanamungu Makelele, John Kalume Mugula, Laura Summerauer, Nora Gallarotti, Landry Cizungu Ntaboba, Kristof Van Oost, Pascal Boeckx, Sebastian Doetterl, Roland Anton Werner, and Johan Six
Biogeosciences, 17, 6207–6218,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.
Bettina K. Gier, Michael Buchwitz, Maximilian Reuter, Peter M. Cox, Pierre Friedlingstein, and Veronika Eyring
Biogeosciences, 17, 6115–6144,Short summary
Models from Coupled Model Intercomparison Project (CMIP) phases 5 and 6 are compared to a satellite data product of column-averaged CO2 mole fractions (XCO2). The previously believed discrepancy of the negative trend in seasonal cycle amplitude in the satellite product, which is not seen in in situ data nor in the models, is attributed to a sampling characteristic. Furthermore, CMIP6 models are shown to have made progress in reproducing the observed XCO2 time series compared to CMIP5.
Samuel T. Wilson, Alia N. Al-Haj, Annie Bourbonnais, Claudia Frey, Robinson W. Fulweiler, John D. Kessler, Hannah K. Marchant, Jana Milucka, Nicholas E. Ray, Parvadha Suntharalingam, Brett F. Thornton, Robert C. Upstill-Goddard, Thomas S. Weber, Damian L. Arévalo-Martínez, Hermann W. Bange, Heather M. Benway, Daniele Bianchi, Alberto V. Borges, Bonnie X. Chang, Patrick M. Crill, Daniela A. del Valle, Laura Farías, Samantha B. Joye, Annette Kock, Jabrane Labidi, Cara C. Manning, John W. Pohlman, Gregor Rehder, Katy J. Sparrow, Philippe D. Tortell, Tina Treude, David L. Valentine, Bess B. Ward, Simon Yang, and Leonid N. Yurganov
Biogeosciences, 17, 5809–5828,Short summary
The oceans are a net source of the major greenhouse gases; however there has been little coordination of oceanic methane and nitrous oxide measurements. The scientific community has recently embarked on a series of capacity-building exercises to improve the interoperability of dissolved methane and nitrous oxide measurements. This paper derives from a workshop which discussed the challenges and opportunities for oceanic methane and nitrous oxide research in the near future.
Najeeb Al-Amin Iddris, Marife D. Corre, Martin Yemefack, Oliver van Straaten, and Edzo Veldkamp
Biogeosciences, 17, 5377–5397,Short summary
We quantified the changes in stem and soil nitrous oxide (N2O) fluxes with forest conversion to cacao agroforestry in the Congo Basin, Cameroon. All forest and cacao trees consistently emitted N2O, contributing 8–38 % of the total (soil and stem) emissions. Forest conversion to extensively managed (>–20 years old) cacao agroforestry had no effect on stem and soil N2O fluxes. Our results highlight the importance of including tree-mediated fluxes in the ecosystem-level N2O budget.
Cédric Morana, Steven Bouillon, Vimac Nolla-Ardèvol, Fleur A. E. Roland, William Okello, Jean-Pierre Descy, Angela Nankabirwa, Erina Nabafu, Dirk Springael, and Alberto V. Borges
Biogeosciences, 17, 5209–5221,Short summary
A growing body of studies challenges the paradigm that methane (CH4) production occurs only under anaerobic conditions. Our field experiments revealed that oxic CH4 production is closely related to phytoplankton metabolism and is indeed a common feature in five contrasting African lakes. Nevertheless, we found that methanotrophic activity in surface waters and CH4 emissions to the atmosphere were predominantly fuelled by CH4 generated in sediments and physically transported to the surface.
Leandra Stephanie Emilia Praetzel, Nora Plenter, Sabrina Schilling, Marcel Schmiedeskamp, Gabriele Broll, and Klaus-Holger Knorr
Biogeosciences, 17, 5057–5078,Short summary
Small lakes are important but variable sources of greenhouse gas emissions. We performed lab experiments to determine spatial patterns and drivers of CO2 and CH4 emission and sediment gas production within a lake. The observed high spatial variability of emissions and production could be explained by the degradability of the sediment organic matter. We did not see correlations between production and emissions and suggest on-site flux measurements as the most accurate way for determing emissions.
François Clayer, Yves Gélinas, André Tessier, and Charles Gobeil
Biogeosciences, 17, 4571–4589,Short summary
Here, we quantified the sediment production of methane and carbon dioxide in lake sediments to better characterize the nature of the organic matter at the origin of these two greenhouse gases. We demonstrate that the production of these gases is not adequately represented in models for deep lake sediments. We thus propose to improve the representation of organic matter degradation reactions in current models for improving predictions of greenhouse gas cycling in aquatic sediments.
David Bastviken, Jonatan Nygren, Jonathan Schenk, Roser Parellada Massana, and Nguyen Thanh Duc
Biogeosciences, 17, 3659–3667,Short summary
This study presents a low-cost way to measure methane emissions applicable in nature and society. This facilitates widespread and affordable methane measurements, which are greatly needed for verifying that greenhouse gas mitigation is effective and for improved quantification of fluxes and how they are regulated. The paper also describes an open-source do-it-yourself methane–carbon dioxide–humidity–temperature logger, to increase the distributed capacity to measure greenhouse gases.
Fortunat Joos, Renato Spahni, Benjamin D. Stocker, Sebastian Lienert, Jurek Müller, Hubertus Fischer, Jochen Schmitt, I. Colin Prentice, Bette Otto-Bliesner, and Zhengyu Liu
Biogeosciences, 17, 3511–3543,Short summary
Results of the first globally resolved simulations of terrestrial carbon and nitrogen (N) cycling and N2O emissions over the past 21 000 years are compared with reconstructed N2O emissions. Modelled and reconstructed emissions increased strongly during past abrupt warming events. This evidence appears consistent with a dynamic response of biological N fixation to increasing N demand by ecosystems, thereby reducing N limitation of plant productivity and supporting a land sink for atmospheric CO2.
Xuefei Li, Outi Wahlroos, Sami Haapanala, Jukka Pumpanen, Harri Vasander, Anne Ojala, Timo Vesala, and Ivan Mammarella
Biogeosciences, 17, 3409–3425,Short summary
We measured CO2 and CH4 fluxes and quantified the global warming potential of different surface areas in a recently created urban wetland in Southern Finland. The ecosystem has a small net climate warming effect which was mainly contributed by the open-water areas. Our results suggest that limiting open-water areas and setting a design preference for areas of emergent vegetation in the establishment of urban wetlands can be a beneficial practice when considering solely the climate impact.
Xiao Ma, Mingshuang Sun, Sinikka T. Lennartz, and Hermann W. Bange
Biogeosciences, 17, 3427–3438,Short summary
Monthly measurements of dissolved methane (CH4), a potent greenhouse gas, were conducted at Boknis Eck (BE), a time-series station in the southwestern Baltic Sea, from June 2006. In general CH4 concentrations increased with depth. High concentrations in the upper layer were linked to saline water inflow. Eckernförde Bay emitted CH4 to the atmosphere throughout the monitoring period. No significant trend was detected in CH4 concentrations or emissions during 2006–2017.
Elizabeth León-Palmero, Alba Contreras-Ruiz, Ana Sierra, Rafael Morales-Baquero, and Isabel Reche
Biogeosciences, 17, 3223–3245,Short summary
CH4 emissions from reservoirs are responsible for the majority of the climatic forcing of these ecosystems. The origin of the recurrent CH4 supersaturation in oxic waters is still controversial. We found that the dissolved CH4 concentration varied by up to 4 orders of magnitude in the water column of 12 reservoirs and was consistently supersaturated. Our findings suggest that photosynthetic picoeukaryotes can play a significant role in determining CH4 concentration in oxic waters.
Marcus B. Wallin, Joachim Audet, Mike Peacock, Erik Sahlée, and Mattias Winterdahl
Biogeosciences, 17, 2487–2498,Short summary
Here we show that small streams draining agricultural areas are potential hotspots for emissions of CO2 to the atmosphere. We further conclude that the variability in stream CO2 concentration over time is very high, caused by variations in both water discharge and primary production. Given the observed high levels of CO2 and its temporally variable nature, agricultural streams clearly need more attention in order to understand and incorporate these dynamics in large-scale extrapolations.
Amiro, B. D., Barr, A. G., Black, T. A., Iwashita, H., Kljun, N., McCaughey, J. H., Morgenstern, K., Murayama, S., Nesic, Z., Orchansky, A. L., and Saigusa, N.: Carbon, energy and water fluxes at mature and disturbed forest sites, Saskatchewan, Canada, Agr. Forest Meteorol., 136, 237–251, https://doi.org/10.1016/j.agrformet.2004.11.012, 2006.
Aubinet, M., Vesala, T., and Papale, D. (eds.): Eddy Covariance: A Practical Guide to Measurement and Data analysis, Springer, Dordrecht, Heidelberg, New York, 2012.
Collineau, S. and Brunet, Y.: Detection of turbulent coherent motions in a forest canopy part I: Wavelet analysis, Bound.-Lay. Meteorol., 65, 357–379, https://doi.org/10.1007/BF00707033, 1993.
Dadi, T., Rubio, E., Martínez-García, E., López-Serrano, F. R., Andrés-Abellán, M., García-Morote, F. A., and De las Heras, J.: Post-wildfire effects on carbon and water vapour dynamics in a Spanish black pine forest, Environ. Sci. Pollut. Res., 22, 4851–62, https://doi.org/10.1007/s11356-014-3744-4, 2015.
de Vries, D. A.: Thermal Properties of Soils, in: Physics of Plant Environme, edited by: van Wijk, W. R., North-Holland Publishing Company, Amsterdam, 210–235, 1963.
Dore, S., Kolb, T. E., Montes-Helu, M., Sullivan, B. W., Winslow, W. D., Hart, S. C., Kaye, J. P., Koch, G. W., and Hungate, B. A.: Long-term impact of a stand-replacing fire on ecosystem CO2 exchange of a ponderosa pine forest, Glob. Change Biol., 14, 1801–1820, https://doi.org/10.1111/j.1365-2486.2008.01613.x, 2008.
EFFIS: COPERNICUS – Emergency Management Service, EFFIS – European Forest Fire Information System, available at: https://effis.jrc.ec.europa.eu/ (last access: 7 January 2021), 2017.
Falge, E., Baldocchi, D., Olson, R., Anthoni, P., Aubinet, M., Bernhofer, C., Burba, G., Ceulemans, R., Clement, R., Dolman, H., Granier, A., Gross, P., Grünwald, T., Hollinger, D., Jensen, N. O., Katul, G., Keronen, P., Kowalski, A., Lai, C. T., Law, B. E., Meyers, T., Moncrieff, J., Moors, E., Munger, J. W., Pilegaard, K., Rannik, Ü., Rebmann, C., Suyker, A., Tenhunen, J., Tu, K., Verma, S., Vesala, T., Wilson, K., and Wofsy, S.: Gap filling strategies for defensible annual sums of net ecosystem exchange, Agr. Forest Meteorol., 107, 43–69, https://doi.org/10.1016/S0168-1923(00)00225-2, 2001.
Foken, T.: Eddy Flux Measurements the Energy Balance Closure Problem: an Overview, Ecol. Appl., 18, 1351–1367, https://doi.org/10.1890/06-0922.1, 2008.
Foken, T., Leuning, R., Oncley, S., Mauder, M., and Aubinet, M.: Corrections and data quality, in: Eddy Covariance: A Practical Guide to Measurement and Data Analysis, edited by: Aubinet, M., Vesala, T., and Papale, D., Springer, Dordrecht, Heidelberg, New York, 85–131, 2012.
Foken, T., Hellmuth, O., Huwe, B., and Sonntag, D.: Physical quantities, in: Handbook of Atmospheric Measurements, edited by: Foken, T., Springer, Cham, in print, 2021.
Fratini, G. and Mauder, M.: Towards a consistent eddy-covariance processing: an intercomparison of EddyPro and TK3, Atmos. Meas. Tech., 7, 2273–2281, https://doi.org/10.5194/amt-7-2273-2014, 2014.
Göckede, M., Foken, T., Aubinet, M., Aurela, M., Banza, J., Bernhofer, C., Bonnefond, J. M., Brunet, Y., Carrara, A., Clement, R., Dellwik, E., Elbers, J., Eugster, W., Fuhrer, J., Granier, A., Grünwald, T., Heinesch, B., Janssens, I. A., Knohl, A., Koeble, R., Laurila, T., Longdoz, B., Manca, G., Marek, M., Markkanen, T., Mateus, J., Matteucci, G., Mauder, M., Migliavacca, M., Minerbi, S., Moncrieff, J., Montagnani, L., Moors, E., Ourcival, J.-M., Papale, D., Pereira, J., Pilegaard, K., Pita, G., Rambal, S., Rebmann, C., Rodrigues, A., Rotenberg, E., Sanz, M. J., Sedlak, P., Seufert, G., Siebicke, L., Soussana, J. F., Valentini, R., Vesala, T., Verbeeck, H., and Yakir, D.: Quality control of CarboEurope flux data – Part 1: Coupling footprint analyses with flux data quality assessment to evaluate sites in forest ecosystems, Biogeosciences, 5, 433–450, https://doi.org/10.5194/bg-5-433-2008, 2008.
Göckede, M., Kittler, F., and Schaller, C.: Quantifying the impact of emission outbursts and non-stationary flow on eddy-covariance CH4 flux measurements using wavelet techniques, Biogeosciences, 16, 3113–3131, https://doi.org/10.5194/bg-16-3113-2019, 2019.
Goulden, M. L., Munger, J. W., Fan, S.-M., Daube, B. C., and Wofsy, S. C.: Measurements of carbon sequestration by long-term eddy covariance: methods and a critical evaluation of accuracy, Glob. Change Biol., 2, 169–182, https://doi.org/10.1111/j.1365-2486.1996.tb00070.x, 1996.
Hillel, D.: Environmental Soil Physics: Fundamentals, Applications, and Environmental Considerations, Academic Press, New York, 1998.
ICNF: 10.o Relatório provisório de incêndios florestais – 2017, available at: http://www2.icnf.pt/portal/florestas/dfci/Resource/doc/rel/2017/10-rel-prov-1jan-31out-2017.pdf (last access: 7 January 2021), 2017.
IPCC: Global Warming of 1.5 ∘C. An IPCC Special Report on the impacts of global warming of 1.5 ∘C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, edited by: Masson-Delmotte, V., Zhai, P., Pörtner, H.-O., Roberts, D., Skea, J., Shukla, P. R., Pirani, A., Moufouma-Okia, W., Péan, C., Pidcock, R., Connors, S., Matthews, J. B. R., Chen, Y., Zhou, X., Gomis, M. I., Lonnoy, E., Maycock, T., Tignor, M., and Waterfield, T., available at: https://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf (last access: 7 January 2021), 2018.
Keeley, J. and Syphard, A.: Climate Change and Future Fire Regimes: Examples from California, Geosciences, 6, 37, https://doi.org/10.3390/geosciences6030037, 2016.
Kohsiek, W., Liebethal, C., Foken, T., Vogt, R., Oncley, S. P., Bernhofer, C., and Debruin, H. A. R.: The Energy Balance Experiment EBEX-2000. Part III: Behaviour and quality of the radiation measurements, Bound.-Lay. Meteorol., 123, 55–75, https://doi.org/10.1007/s10546-006-9135-8, 2007.
Lasslop, G., Reichstein, M., Papale, D., Richardson, A., Arneth, A., Barr, A., Stoy, P., and Wohlfahrt, G.: Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: Critical issues and global evaluation, Glob. Change Biol., 16, 187–208, https://doi.org/10.1111/j.1365-2486.2009.02041.x, 2010.
Leighton-Boyce, G., Doerr, S. H., Shakesby, R. A., and Walsh, R. P. D.: Quantifying the impact of soil water repellency on overland flow generation and erosion: a new approach using rainfall simulation and wetting agent on in situ soil, Hydrol. Process., 21, 2337–2345, https://doi.org/10.1002/hyp.6744, 2007.
Li, M., Babel, W., Tanaka, K., and Foken, T.: Note on the application of planar-fit rotation for non-omnidirectional sonic anemometers, Atmos. Meas. Tech., 6, 221–229, https://doi.org/10.5194/amt-6-221-2013, 2013.
Luyssaert, S., Ciais, P., Piao, S. L., Schulze, E. D., Jung, M., Zaehle, S., Schelhaas, M. J., Reichstein, M., Churkina, G., Papale, D., Abril, G., Beer, C., Grace, J., Loustau, D., Matteucci, G., Magnani, F., Nabuurs, G. J., Verbeeck, H., Sulkava, M., van der Werf, G. R., and Janssens, I. A.: The European carbon balance. Part 3: Forests, Glob. Change Biol., 16, 1429–1450, https://doi.org/10.1111/j.1365-2486.2009.02056.x, 2010.
Maia, P., Pausas, J. G., Arcenegui, V., Guerrero, C., Pérez-Bejarano, A., Mataix-Solera, J., Varela, M. E. T., Fernandes, I., Pedrosa, E. T., and Keizer, J. J.: Wildfire effects on the soil seed bank of a maritime pine stand – The importance of fire severity, Geoderma, 191, 80–88, https://doi.org/10.1016/J.GEODERMA.2012.02.001, 2012.
Marañón-Jiménez, S., Castro, J., Kowalski, A. S., Serrano-Ortiz, P., Reverter, B. R., Sánchez-Cañete, E. P., and Zamora, R.: Post-fire soil respiration in relation to burnt wood management in a Mediterranean mountain ecosystem, Forest Ecol. Manag., 261, 1436–1447, https://doi.org/10.1016/j.foreco.2011.01.030, 2011.
Mauder, M., Foken, T., and Cuxart, J.: Surface-Energy-Balance Closure over Land: A Review, Bound.-Lay. Meteorol., 177, 395–426, https://doi.org/10.1007/s10546-020-00529-6, 2020.
Metzger, S., Ayres, E., Durden, D., Florian, C., Lee, R., Lunch, C., Luo, H., Pingintha-Durden, N., Roberti, J. A., SanClements, M., Sturtevant, C., Xu, K., and Zulueta, R. C.: From NEON field sites to data portal: A community resource for surface-atmosphere research comes online, B. Am. Meteorol. Soc., 100, 2305–2325, https://doi.org/10.1175/BAMS-D-17-0307.1, 2019.
Mkhabela, M. S., Amiro, B. D., Barr, A. G., Black, T. A., Hawthorne, I., Kidston, J., McCaughey, J. H., Orchansky, A. L., Nesic, Z., Sass, A., Shashkov, A., and Zha, T.: Comparison of carbon dynamics and water use efficiency following fire and harvesting in Canadian boreal forests, Agr. Forest Meteorol., 149, 783–794, https://doi.org/10.1016/j.agrformet.2008.10.025, 2009.
Moffat, A. M., Papale, D., Reichstein, M., Hollinger, D. Y., Richardson, A. D., Barr, A. G., Beckstein, C., Braswell, B. H., Churkina, G., Desai, A. R., Falge, E., Gove, J. H., Heimann, M., Hui, D., Jarvis, A. J., Kattge, J., Noormets, A., and Stauch, V. J.: Comprehensive comparison of gap-filling techniques for eddy covariance net carbon fluxes, Agr. Forest Meteorol., 147, 209–232, https://doi.org/10.1016/j.agrformet.2007.08.011, 2007.
Moreaux, V., Lamaud, É., Bosc, A., Bonnefond, J. M., Medlyn, B. E., and Loustau, D.: Paired comparison of water, energy and carbon exchanges over two young maritime pine stands (Pinus pinaster Ait.): Effects of thinning and weeding in the early stage of tree growth, Tree Physiol., 31, 903–921, https://doi.org/10.1093/treephys/tpr048, 2011.
Papale, D., Reichstein, M., Aubinet, M., Canfora, E., Bernhofer, C., Kutsch, W., Longdoz, B., Rambal, S., Valentini, R., Vesala, T., and Yakir, D.: Towards a standardized processing of Net Ecosystem Exchange measured with eddy covariance technique: algorithms and uncertainty estimation, Biogeosciences, 3, 571–583, https://doi.org/10.5194/bg-3-571-2006, 2006.
Rebmann, C., Aubinet, M., Schmid, H., Arriga, N., Aurela, M., Burba, G., Clement, R., De Ligne, A., Fratini, G., Gielen, B., Grace, J., Graf, A., Gross, P., Haapanala, S., Herbst, M., Hörtnagl, L., Ibrom, A., Joly, L., Kljun, N., Kolle, O., Kowalski, A., Lindroth, A., Loustau, D., Mammarella, I., Mauder, M., Merbold, L., Metzger, S., Mölder, M., Montagnani, L., Papale, D., Pavelka, M., Peichl, M., Roland, M., Serrano-Ortiz, P., Siebicke, L., Steinbrecher, R., Tuovinen, J. P., Vesala, T., Wohlfahrt, G., and Franz, D.: ICOS eddy covariance flux-station site setup: A review, Int. Agrophys., 32, 471–494, https://doi.org/10.1515/intag-2017-0044, 2018.
Reichstein, M., Falge, E., Baldocchi, D., Papale, D., Aubinet, M., Berbigier, P., Bernhofer, C., Buchmann, N., Gilmanov, T., Granier, A., Grünwald, T., Havránková, K., Ilvesniemi, H., Janous, D., Knohl, A., Laurila, T., Lohila, A., Loustau, D., Matteucci, G., Meyers, T., Miglietta, F., Ourcival, J. M., Pumpanen, J., Rambal, S., Rotenberg, E., Sanz, M., Tenhunen, J., Seufert, G., Vaccari, F., Vesala, T., Yakir, D., and Valentini, R.: On the separation of net ecosystem exchange into assimilation and ecosystem respiration: Review and improved algorithm, Glob. Change Biol., 11, 1424–1439, https://doi.org/10.1111/j.1365-2486.2005.001002.x, 2005.
Richardson, A. D., Braswell, B. H., Hollinger, D. Y., Burman, P., Davidson, E. A., Evans, R. S., Flanagan, L. B., Munger, J. W., Savage, K., Urbanski, S. P., and Wofsy, S. C.: Comparing simple respiration models for eddy flux and dynamic chamber data, Agr. Forest Meteorol., 141, 219–234, https://doi.org/10.1016/j.agrformet.2006.10.010, 2006.
Ruiz-Peinado, R., Bravo-Oviedo, A., Lopez-Senespleda, E., Bravo, F., and Rio, M.: Forest management and carbon sequestration in the Mediterranean region: A review, For. Syst., 26, eR04S, https://doi.org/10.5424/fs/2017262-11205, 2017.
Santana, V. M., González-Pelayo, O., Maia, P. A. A., Varela T., M. E., Valdecantos, A., Ramón Vallejo, V., and Jacob Keizer, J.: Effects of fire recurrence and different salvage logging techniques on carbon storage in Pinus pinaster forests from northern Portugal, Eur. J. For. Res., 135, 1107–1117, https://doi.org/10.1007/s10342-016-0997-0, 2016.
Schaller, C., Göckede, M., and Foken, T.: Flux calculation of short turbulent events – comparison of three methods, Atmos. Meas. Tech., 10, 869–880, https://doi.org/10.5194/amt-10-869-2017, 2017.
Schaller, C., Kittler, F., Foken, T., and Göckede, M.: Characterisation of short-term extreme methane fluxes related to non-turbulent mixing above an Arctic permafrost ecosystem, Atmos. Chem. Phys., 19, 4041–4059, https://doi.org/10.5194/acp-19-4041-2019, 2019.
Serrano-Ortiz, P., Roland, M., Sanchez-Moral, S., Janssens, I. A., Domingo, F., Goddéris, Y., and Kowalski, A. S.: Hidden, abiotic CO2 flows and gaseous reservoirs in the terrestrial carbon cycle: Review and perspectives, Agr. Forest Meteorol., 150, 321–329, https://doi.org/10.1016/j.agrformet.2010.01.002, 2010.
Serrano-Ortiz, P., Marañón-Jiménez, S., Reverter, B. R., Sánchez-Cañete, E. P., Castro, J., Zamora, R., and Kowalski, A. S.: Post-fire salvage logging reduces carbon sequestration in Mediterranean coniferous forest, Forest Ecol. Manag., 262, 2287–2296, https://doi.org/10.1016/j.foreco.2011.08.023, 2011.
Sommers, W. T., Loehman, R. A., and Hardy, C. C.: Wildland fire emissions, carbon, and climate: Science overview and knowledge needs, Forest Ecology and Management, 317, 1–8, https://doi.org/10.1016/J.FORECO.2013.12.014, 2014.
Vega, J. A., Fontúrbel, T., Merino, A., Fernández, C., Ferreiro, A., and Jiménez, E.: Testing the ability of visual indicators of soil burn severity to reflect changes in soil chemical and microbial properties in pine forests and shrubland, Plant Soil, 369, 73–91, https://doi.org/10.1007/s11104-012-1532-9, 2013.
Wutzler, T., Lucas-Moffat, A., Migliavacca, M., Knauer, J., Sickel, K., Šigut, L., Menzer, O., and Reichstein, M.: Basic and extensible post-processing of eddy covariance flux data with REddyProc, Biogeosciences, 5015–5030, https://doi.org/10.5194/bg-15-5015-2018, 2018.
Forest fires have a significant impact on carbon dioxide emissions. The present study from a pine forest in Portugal is one of the few where measurements of CO2 fluxes were started immediately (1.5 months) after the forest fire. Carbon dioxide emissions were linked to soil humidity. Therefore, they started after the beginning of the rainfall in autumn. Due to the beginning of vegetation, the site was already a carbon dioxide sink the following year.
Forest fires have a significant impact on carbon dioxide emissions. The present study from a...