Articles | Volume 10, issue 12
Research article 06 Dec 2013
Research article | 06 Dec 2013
Shifting environmental controls on CH4 fluxes in a sub-boreal peatland
T. G. Pypker et al.
P. Attarod, Q. Tang, J. T. Van Stan II, T. G. Pypker, and X. Liu
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-4-W18, 117–125,
P. Attarod, Q. Tang, J. T. Van Stan II, T. G. Pypker, and X. Liu
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-4-W18, 117–125,
Paul A. Moore, Maxwell C. Lukenbach, Dan K. Thompson, Nick Kettridge, Gustaf Granath, and James M. Waddington
Biogeosciences, 16, 3491–3506,Short summary
Using very-high-resolution digital elevation models (DEMs), we assessed the basic structure and microtopographic variability of hummock–hollow plots at boreal and hemi-boreal sites primarily in North America. Using a simple model of peatland biogeochemical function, our results suggest that both surface heating and moss productivity may not be adequately resolved in models which only consider idealized hummock–hollow units.
Gustaf Granath, Håkan Rydin, Jennifer L. Baltzer, Fia Bengtsson, Nicholas Boncek, Luca Bragazza, Zhao-Jun Bu, Simon J. M. Caporn, Ellen Dorrepaal, Olga Galanina, Mariusz Gałka, Anna Ganeva, David P. Gillikin, Irina Goia, Nadezhda Goncharova, Michal Hájek, Akira Haraguchi, Lorna I. Harris, Elyn Humphreys, Martin Jiroušek, Katarzyna Kajukało, Edgar Karofeld, Natalia G. Koronatova, Natalia P. Kosykh, Mariusz Lamentowicz, Elena Lapshina, Juul Limpens, Maiju Linkosalmi, Jin-Ze Ma, Marguerite Mauritz, Tariq M. Munir, Susan M. Natali, Rayna Natcheva, Maria Noskova, Richard J. Payne, Kyle Pilkington, Sean Robinson, Bjorn J. M. Robroek, Line Rochefort, David Singer, Hans K. Stenøien, Eeva-Stiina Tuittila, Kai Vellak, Anouk Verheyden, James Michael Waddington, and Steven K. Rice
Biogeosciences, 15, 5189–5202,Short summary
Peat constitutes a long-term archive for climate reconstruction by using the isotopic composition of carbon and oxygen. We analysed isotopes in two peat moss species across North America and Eurasia. Peat (moss tissue) isotope composition was predicted by soil moisture and isotopic composition of the rainwater but differed between species. Our results suggest that isotope composition can be used on a large scale for climatic reconstructions but that such models should be species-specific.
Simon J. Dixon, Max C. Lukenbach, Nicholas Kettridge, Kevin J. Devito, Richard M. Petrone, Carl A. Mendoza, and J. Michael Waddington
Hydrol. Earth Syst. Sci. Discuss.,
Revised manuscript has not been submittedShort summary
Using a computer model we are able to show that a layer of frozen soil that forms in peatlands during the winter can substantially affect how dry or wet the surface of the peat remains as it starts to grow after winter snowmelt. We find there is a lot of variability in moisture contents driven by the frozen layer and this will lead to variability in which areas of a peatland are vulnerable to burning during spring wildfires.
Related subject area
Biogeochemistry: WetlandsFactors controlling Carex brevicuspis leaf litter decomposition and its contribution to surface soil organic carbon pool at different water levelsExploring constraints on a wetland methane emission ensemble (WetCHARTs) using GOSAT observationsGlobal peatland area and carbon dynamics from the Last Glacial Maximum to the present – a process-based model investigationVascular plants affect properties and decomposition of moss-dominated peat, particularly at elevated temperaturesDenitrification and associated nitrous oxide and carbon dioxide emissions from the Amazonian wetlandsDrivers of seasonal- and event-scale DOC dynamics at the outlet of mountainous peatlands revealed by high-frequency monitoringComparison of eddy covariance CO2 and CH4 fluxes from mined and recently rewetted sections in a northwestern German cutover bogMicrotopography is a fundamental organizing structure of vegetation and soil chemistry in black ash wetlandsInteracting effects of vegetation components and water level on methane dynamics in a boreal fenLow methane emissions from a boreal wetland constructed on oil sand mine tailingsEvidence for preferential protein depolymerization in wetland soils in response to external nitrogen availability provided by a novel FTIR routineSaltwater reduces potential CO2 and CH4 production in peat soils from a coastal freshwater forested wetlandReviews and syntheses: Greenhouse gas exchange data from drained organic forest soils – a review of current approaches and recommendations for future researchEffects of sterilization techniques on chemodenitrification and N2O production in tropical peat soil microcosmsModelling long-term blanket peatland development in eastern ScotlandCushion bogs are stronger carbon dioxide net sinks than moss-dominated bogs as revealed by eddy covariance measurements on Tierra del Fuego, ArgentinaHumic surface waters of frozen peat bogs (permafrost zone) are highly resistant to bio- and photodegradationMulti-year methane ebullition measurements from water and bare peat surfaces of a patterned boreal bogSulfate deprivation triggers high methane production in a disturbed and rewetted coastal peatlandRhizosphere to the atmosphere: contrasting methane pathways, fluxes, and geochemical drivers across the terrestrial–aquatic wetland boundaryMulti-year effect of wetting on CH4 flux at taiga–tundra boundary in northeastern Siberia deduced from stable isotope ratios of CH4Zero to moderate methane emissions in a densely rooted, pristine Patagonian bog – biogeochemical controls as revealed from isotopic evidenceFluvial organic carbon fluxes from oil palm plantations on tropical peatlandReviews and syntheses: 210Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems – setting the record straightResponse of hydrology and CO2 flux to experimentally altered rainfall frequency in a temperate poor fen, southern Ontario, CanadaGlobal-change effects on early-stage decomposition processes in tidal wetlands – implications from a global survey using standardized litterYear-round simulated methane emissions from a permafrost ecosystem in Northeast SiberiaSmall spatial variability in methane emission measured from a wet patterned boreal bogTechnical note: A simple approach for efficient collection of field reference data for calibrating remote sensing mapping of northern wetlandsTechnical note: Comparison of methane ebullition modelling approaches used in terrestrial wetland modelsGeomorphic influences on the contribution of vegetation to soil C accumulation and accretion in Spartina alterniflora marshesSouthern Hemisphere bog persists as a strong carbon sink during droughtsThe effect of drought on dissolved organic carbon (DOC) release from peatland soil and vegetation sourcesAnnual greenhouse gas budget for a bog ecosystem undergoing restoration by rewettingTemporal changes in photoreactivity of dissolved organic carbon and implications for aquatic carbon fluxes from peatlandsSymbiosis revisited: phosphorus and acid buffering stimulate N2 fixation but not Sphagnum growthAttaining whole-ecosystem warming using air and deep-soil heating methods with an elevated CO2 atmosphereAquatic macrophytes can be used for wastewater polishing but not for purification in constructed wetlandsControls on soil organic carbon stocks in tidal marshes along an estuarine salinity gradientWetland eco-engineering: measuring and modeling feedbacks of oxidation processes between plants and clay-rich materialMapping of West Siberian taiga wetland complexes using Landsat imagery: implications for methane emissionsWater level, vegetation composition, and plant productivity explain greenhouse gas fluxes in temperate cutover fens after inundationHigh net CO2 and CH4 release at a eutrophic shallow lake on a formerly drained fenMercury methylation in paddy soil: source and distribution of mercury species at a Hg mining area, Guizhou Province, ChinaThe fate of 15N-nitrate in mesocosms from five European peatlands differing in long-term nitrogen deposition rateSpatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basinSeasonal dynamics of carbon and nutrients from two contrasting tropical floodplain systems in the Zambezi River basinModel estimates of climate controls on pan-Arctic wetland methane emissionsSediment properties and CO2 efflux from intact and cleared temperate mangrove forestsModeling micro-topographic controls on boreal peatland hydrology and methane fluxes
Lianlian Zhu, Zhengmiao Deng, Yonghong Xie, Xu Li, Feng Li, Xinsheng Chen, Yeai Zou, Chengyi Zhang, and Wei Wang
Biogeosciences, 18, 1–11,Short summary
We conducted a Carex brevicuspis leaf litter input experiment to clarify the intrinsic factors controlling litter decomposition and quantify its contribution to the soil organic carbon pool at different water levels. Our results revealed that the water level in natural wetlands influenced litter decomposition mainly by leaching and microbial activity, by extension, and affected the wetland surface carbon pool.
Robert J. Parker, Chris Wilson, A. Anthony Bloom, Edward Comyn-Platt, Garry Hayman, Joe McNorton, Hartmut Boesch, and Martyn P. Chipperfield
Biogeosciences, 17, 5669–5691,Short summary
Wetlands contribute the largest uncertainty to the atmospheric methane budget. WetCHARTs is a simple, data-driven model that estimates wetland emissions using observations of precipitation and temperature. We perform the first detailed evaluation of WetCHARTs against satellite data and find it performs well in reproducing the observed wetland methane seasonal cycle for the majority of wetland regions. In regions where it performs poorly, we highlight incorrect wetland extent as a key reason.
Jurek Müller and Fortunat Joos
Biogeosciences, 17, 5285–5308,Short summary
We present an in-depth model analysis of transient peatland area and carbon dynamics over the last 22 000 years. Our novel results show that the consideration of both gross positive and negative area changes are necessary to understand the transient evolution of peatlands and their net effect on atmospheric carbon. The study includes the attributions to drivers through factorial simulations, assessments of uncertainty from climate forcing, and determination of the global net carbon balance.
Lilli Zeh, Marie Theresa Igel, Judith Schellekens, Juul Limpens, Luca Bragazza, and Karsten Kalbitz
Biogeosciences, 17, 4797–4813,
Jérémy Guilhen, Ahmad Al Bitar, Sabine Sauvage, Marie Parrens, Jean-Michel Martinez, Gwenael Abril, Patricia Moreira-Turcq, and José-Miguel Sánchez-Pérez
Biogeosciences, 17, 4297–4311,Short summary
The quantity of greenhouse gases (GHGs) released to the atmosphere by human industries and agriculture, such as carbon dioxide (CO2) and nitrous oxide (N2O), has been constantly increasing for the last few decades. This work develops a methodology which makes consistent both satellite observations and modelling of the Amazon basin to identify and quantify the role of wetlands in GHG emissions. We showed that these areas produce non-negligible emissions and are linked to land use.
Thomas Rosset, Stéphane Binet, Jean-Marc Antoine, Emilie Lerigoleur, François Rigal, and Laure Gandois
Biogeosciences, 17, 3705–3722,Short summary
Peatlands export a large amount of DOC through inland waters. This study aims at identifying the mechanisms controlling the DOC concentration at the outlet of two mountainous peatlands in the French Pyrenees. Peat water temperature and water table dynamics are shown to drive seasonal- and event-scale DOC concentration variation. According to water recession times, peatlands appear as complexes of different hydrological and biogeochemical units supplying inland waters at different rates.
David Holl, Eva-Maria Pfeiffer, and Lars Kutzbach
Biogeosciences, 17, 2853–2874,Short summary
We measured greenhouse gas (GHG) fluxes at a bog site in northwestern Germany that has been heavily degraded by peat mining. During the 2-year investigation period, half of the area was still being mined, whereas the remaining half had been rewetted shortly before. We could therefore estimate the impact of rewetting on GHG flux dynamics. Rewetting had a considerable effect on the annual GHG balance and led to increased (up to 84 %) methane and decreased (up to 40 %) carbon dioxide release.
Jacob S. Diamond, Daniel L. McLaughlin, Robert A. Slesak, and Atticus Stovall
Biogeosciences, 17, 901–915,Short summary
Many wetland systems exhibit lumpy, or uneven, soil surfaces where higher points are called hummocks and lower points are called hollows. We found that, while hummocks extended only ~ 20 cm above hollow surfaces, they exhibited distinct plant communities, plant growth, and soil properties. Differences between hummocks and hollows were the greatest in wetter sites, supporting the hypothesis that plants create and maintain their own hummocks in response to saturated soil conditions.
Terhi Riutta, Aino Korrensalo, Anna M. Laine, Jukka Laine, and Eeva-Stiina Tuittila
Biogeosciences, 17, 727–740,Short summary
We studied the role of plant species groups in peatland methane fluxes under natural conditions and lowered water level. At a natural water level, sedges and mosses increased the fluxes. At a lower water level, the impact of plant groups on the fluxes was small. Only at a high water level did vegetation regulate the fluxes. The results are relevant for assessing peatland methane fluxes in a changing climate, as peatland water level and vegetation are predicted to change.
M. Graham Clark, Elyn R. Humphreys, and Sean K. Carey
Biogeosciences, 17, 667–682,Short summary
Natural and restored wetlands typically emit methane to the atmosphere. However, we found that a wetland constructed after oil sand mining in boreal Canada using organic soils from local peatlands had negligible emissions of methane in its first 3 years. Methane production was likely suppressed due to an abundance of alternate inorganic electron acceptors. Methane emissions may increase in the future if the alternate electron acceptors continue to decrease.
Hendrik Reuter, Julia Gensel, Marcus Elvert, and Dominik Zak
Biogeosciences, 17, 499–514,Short summary
Using infrared spectroscopy, we developed a routine to disentangle microbial nitrogen (N) and plant N in decomposed litter. In a decomposition experiment in three wetland soils, this routine revealed preferential protein depolymerization as a decomposition-site-dependent parameter, unaffected by variations in initial litter N content. In Sphagnum peat, preferential protein depolymerization led to a N depletion of still-unprocessed litter tissue, i.e., a gradual loss of litter quality.
Kevan J. Minick, Bhaskar Mitra, Asko Noormets, and John S. King
Biogeosciences, 16, 4671–4686,Short summary
Sea level rise alters hydrology and vegetation in coastal wetlands. We studied effects of freshwater, saltwater, and wood on soil microbial activity in a freshwater forested wetland. Saltwater reduced CO2/CH4 production compared to freshwater, suggesting large changes in greenhouse gas production and microbial activity are possible due to saltwater intrusion into freshwater wetlands but that the availability of C in the form of dead wood (as forests transition to marsh) may alter the magnitude.
Jyrki Jauhiainen, Jukka Alm, Brynhildur Bjarnadottir, Ingeborg Callesen, Jesper R. Christiansen, Nicholas Clarke, Lise Dalsgaard, Hongxing He, Sabine Jordan, Vaiva Kazanavičiūtė, Leif Klemedtsson, Ari Lauren, Andis Lazdins, Aleksi Lehtonen, Annalea Lohila, Ainars Lupikis, Ülo Mander, Kari Minkkinen, Åsa Kasimir, Mats Olsson, Paavo Ojanen, Hlynur Óskarsson, Bjarni D. Sigurdsson, Gunnhild Søgaard, Kaido Soosaar, Lars Vesterdal, and Raija Laiho
Biogeosciences, 16, 4687–4703,Short summary
We collated peer-reviewed publications presenting GHG flux data for drained organic forest soils in boreal and temperate climate zones, focusing on data that have been used, or have the potential to be used, for estimating net annual soil GHG emission/removals. We evaluated the methods in data collection and identified major gaps in background/environmental data. Based on these, we developed suggestions for future GHG data collection to increase data applicability in syntheses and inventories.
Steffen Buessecker, Kaitlyn Tylor, Joshua Nye, Keith E. Holbert, Jose D. Urquiza Muñoz, Jennifer B. Glass, Hilairy E. Hartnett, and Hinsby Cadillo-Quiroz
Biogeosciences, 16, 4601–4612,Short summary
We investigated the potential for chemical reduction of nitrite into nitrous oxide (N2O) in soils from tropical peat. Among treatments, irradiation resulted in the lowest biological interference and least change of native soil chemistry (iron and organic matter). Nitrite depletion was as high in live or irradiated soils, and N2O production was significant in all tests. Thus, nonbiological production of N2O may be widely underestimated in wetlands and tropical peatlands.
Ward Swinnen, Nils Broothaerts, and Gert Verstraeten
Biogeosciences, 16, 3977–3996,Short summary
In this study, a new model is presented, which was specifically designed to study the development and carbon storage of blanket peatlands since the last ice age. In the past, two main processes (declining forest cover and rising temperatures) have been proposed as drivers of blanket peatland development on the British Isles. The simulations performed in this study support the temperature hypothesis for the blanket peatlands in the Cairngorms Mountains of central Scotland.
David Holl, Verónica Pancotto, Adrian Heger, Sergio Jose Camargo, and Lars Kutzbach
Biogeosciences, 16, 3397–3423,Short summary
We present 2 years of eddy covariance carbon dioxide flux data from two Southern Hemisphere peatlands on Tierra del Fuego. One of the investigated sites is a type of bog exclusive to the Southern Hemisphere, which is dominated by vascular, cushion-forming plants and is particularly understudied. One result of this study is that these cushion bogs apparently are highly productive in comparison to Northern and Southern Hemisphere moss-dominated bogs.
Liudmila S. Shirokova, Artem V. Chupakov, Svetlana A. Zabelina, Natalia V. Neverova, Dahedrey Payandi-Rolland, Carole Causserand, Jan Karlsson, and Oleg S. Pokrovsky
Biogeosciences, 16, 2511–2526,Short summary
Regardless of the size and landscape context of surface water in frozen peatland in NE Europe, the bio- and photo-degradability of dissolved organic matter (DOM) over a 1-month incubation across a range of temperatures was below 10 %. We challenge the paradigm of dominance of photolysis and biodegradation in DOM processing in surface waters from frozen peatland, and we hypothesize peat pore-water DOM degradation and respiration of sediments to be the main drivers of CO2 emission in this region.
Elisa Männistö, Aino Korrensalo, Pavel Alekseychik, Ivan Mammarella, Olli Peltola, Timo Vesala, and Eeva-Stiina Tuittila
Biogeosciences, 16, 2409–2421,Short summary
We studied methane emitted as episodic bubble release (ebullition) from water and bare peat surfaces of a boreal bog over three years. There was more ebullition from water than from bare peat surfaces, and it was controlled by peat temperature, water level, atmospheric pressure and the weekly temperature sum. However, the contribution of methane bubbles to the total ecosystem methane emission was small. This new information can be used to improve process models of peatland methane dynamics.
Franziska Koebsch, Matthias Winkel, Susanne Liebner, Bo Liu, Julia Westphal, Iris Schmiedinger, Alejandro Spitzy, Matthias Gehre, Gerald Jurasinski, Stefan Köhler, Viktoria Unger, Marian Koch, Torsten Sachs, and Michael E. Böttcher
Biogeosciences, 16, 1937–1953,Short summary
In natural coastal wetlands, high supplies of marine sulfate suppress methane production. We found these natural methane suppression mechanisms to be suspended by humane interference in a brackish wetland. Here, diking and freshwater rewetting had caused an efficient depletion of the sulfate reservoir and opened up favorable conditions for an intensive methane production. Our results demonstrate how human disturbance can turn coastal wetlands into distinct sources of the greenhouse gas methane.
Luke C. Jeffrey, Damien T. Maher, Scott G. Johnston, Kylie Maguire, Andrew D. L. Steven, and Douglas R. Tait
Biogeosciences, 16, 1799–1815,Short summary
Wetlands represent the largest natural source of methane (CH4), so understanding CH4 drivers is important for management and climate models. We compared several CH4 pathways of a remediated subtropical Australian wetland. We found permanently inundated sites emitted more CH4 than seasonally inundated sites and that the soil properties of each site corresponded to CH4 emissions. This suggests that selective wetland remediation of favourable soil types may help to mitigate unwanted CH4 emissions.
Ryo Shingubara, Atsuko Sugimoto, Jun Murase, Go Iwahana, Shunsuke Tei, Maochang Liang, Shinya Takano, Tomoki Morozumi, and Trofim C. Maximov
Biogeosciences, 16, 755–768,Short summary
(1) Wetting event with extreme precipitation increased methane emission from wetland, especially two summers later, despite the decline in water level after the wetting. (2) Isotopic compositions of methane in soil pore water suggested enhancement of production and less significance of oxidation in the following two summers after the wetting event. (3) Duration of water saturation in the active layer may be important for predicting methane emission after a wetting event in permafrost ecosystems.
Wiebke Münchberger, Klaus-Holger Knorr, Christian Blodau, Verónica A. Pancotto, and Till Kleinebecker
Biogeosciences, 16, 541–559,Short summary
Processes governing CH4 dynamics have been scarcely studied in southern hemispheric bogs. These can be dominated by cushion-forming plants with deep and dense roots suppressing emissions. Here we demonstrate how the spatial distribution of root activity drives a pronounced pattern of CH4 emissions, likewise also possible in densely rooted northern bogs. We conclude that presence of cushion vegetation as a proxy for negligible CH4 emissions from cushion bogs needs to be interpreted with caution.
Sarah Cook, Mick J. Whelan, Chris D. Evans, Vincent Gauci, Mike Peacock, Mark H. Garnett, Lip Khoon Kho, Yit Arn Teh, and Susan E. Page
Biogeosciences, 15, 7435–7450,Short summary
This paper presents the first comprehensive assessment of fluvial organic carbon loss from oil palm plantations on tropical peat: a carbon loss pathway previously unaccounted for from carbon budgets. Carbon in the water draining four plantations in Sarawak was monitored across a 1-year period. Greater fluvial carbon losses were linked to sites with lower water tables. These data will be used to complete the carbon budget from these ecosystems and assess the full impact of this land conversion.
Ariane Arias-Ortiz, Pere Masqué, Jordi Garcia-Orellana, Oscar Serrano, Inés Mazarrasa, Núria Marbà, Catherine E. Lovelock, Paul S. Lavery, and Carlos M. Duarte
Biogeosciences, 15, 6791–6818,Short summary
Efforts to include tidal marsh, mangrove and seagrass ecosystems in existing carbon mitigation strategies are limited by a lack of estimates of carbon accumulation rates (CARs). We discuss the use of 210Pb dating to determine CARs in these habitats, which are often composed of heterogeneous sediments and affected by sedimentary processes. Results show that obtaining reliable geochronologies in these systems is ambitious, but estimates of mean 100-year CARs are mostly secure within 20 % error.
Danielle D. Radu and Tim P. Duval
Biogeosciences, 15, 3937–3951,Short summary
Climate change can shift rainfall into fewer, more intense events with longer dry periods, leading to changes in peatland hydrology and carbon cycling. We manipulated rain events over three peatland plant types (moss, sedge, and shrub). We found increasing regime intensity led to drier surface soils and deeper water tables, reducing plant carbon uptake. Mosses became sources of CO2 after >3 consecutive dry days. This study shows peatlands may become smaller sinks for carbon due to rain changes.
Peter Mueller, Lisa M. Schile-Beers, Thomas J. Mozdzer, Gail L. Chmura, Thomas Dinter, Yakov Kuzyakov, Alma V. de Groot, Peter Esselink, Christian Smit, Andrea D'Alpaos, Carles Ibáñez, Magdalena Lazarus, Urs Neumeier, Beverly J. Johnson, Andrew H. Baldwin, Stephanie A. Yarwood, Diana I. Montemayor, Zaichao Yang, Jihua Wu, Kai Jensen, and Stefanie Nolte
Biogeosciences, 15, 3189–3202,
Karel Castro-Morales, Thomas Kleinen, Sonja Kaiser, Sönke Zaehle, Fanny Kittler, Min Jung Kwon, Christian Beer, and Mathias Göckede
Biogeosciences, 15, 2691–2722,Short summary
We present year-round methane emissions from wetlands in Northeast Siberia that were simulated with a land surface model. Ground-based flux measurements from the same area were used for evaluation of the model results, finding a best agreement with the observations in the summertime emissions that take place in this region predominantly through plants. During winter, methane emissions through the snow contribute 4 % of the total annual methane budget, but these are still underestimated.
Aino Korrensalo, Elisa Männistö, Pavel Alekseychik, Ivan Mammarella, Janne Rinne, Timo Vesala, and Eeva-Stiina Tuittila
Biogeosciences, 15, 1749–1761,Short summary
We measured methane fluxes of a boreal bog from six different plant community types in 2012–2014. We found only little variation in methane fluxes among plant community types. Peat temperature as well as both leaf area of plant species with air channels and of all vegetation are important factors controlling the fluxes. We also detected negative net fluxes indicating methane consumption each year. Our results can be used to improve the models of peatland methane dynamics under climate change.
Magnus Gålfalk, Martin Karlson, Patrick Crill, Philippe Bousquet, and David Bastviken
Biogeosciences, 15, 1549–1557,Short summary
We describe a quick in situ method for mapping ground surface cover, calculating areas of each surface type in a 10 x 10 m plot for each measurement. The method is robust, weather-independent, easily carried out, and uses wide-field imaging with a standard remote-controlled camera mounted on a very long extendible monopod from a height of 3–4.5 m. The method enables collection of detailed field reference data, critical in many remote sensing applications, such as wetland mapping.
Olli Peltola, Maarit Raivonen, Xuefei Li, and Timo Vesala
Biogeosciences, 15, 937–951,Short summary
Emission via bubbling, i.e. ebullition, is one of the main CH4 emission pathways from wetlands to the atmosphere, yet it is still coarsely represented in wetland CH4 models. In this study three ebullition modelling approaches are evaluated. Modeled annual CH4 emissions were similar, whereas temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence realistic description of ebullition is needed when models are compared to and calibrated against measurements.
Tracy Elsey-Quirk and Viktoria Unger
Biogeosciences, 15, 379–397,Short summary
Salt marshes have high rates of plant productivity and carbon accumulation. For this study, we found that differences in environmental conditions between estuary types were important in determining the source and stability of soil organic carbon. Specifically, sediment availability was extremely important in promoting high plant productivity and carbon accumulation in an estuary which was sediment-limited. In a sediment-rich estuary vegetation–soil-carbon relationships were weaker.
Jordan P. Goodrich, David I. Campbell, and Louis A. Schipper
Biogeosciences, 14, 4563–4576,
Jonathan P. Ritson, Richard E. Brazier, Nigel J. D. Graham, Chris Freeman, Michael R. Templeton, and Joanna M. Clark
Biogeosciences, 14, 2891–2902,Short summary
Peatlands are a globally important store of carbon; however increased droughts in the future may affect their ability to sequester carbon. Using laboratory simulations we show that droughts, through exposure to oxygen, greatly increase the quantity and alter the quality of dissolved organic carbon (DOC) released from peat. Catchment management which keeps water tables high to limit oxygen exposure is therefore likely to deliver positive water quality outcomes.
Sung-Ching Lee, Andreas Christen, Andrew T. Black, Mark S. Johnson, Rachhpal S. Jassal, Rick Ketler, Zoran Nesic, and Markus Merkens
Biogeosciences, 14, 2799–2814,Short summary
Burns Bog in Vancouver is the largest peatland on North America's west coast. It is undergoing rewetting as a restoration management after peat harvesting. Rewetting of disturbed areas facilitates their ecological recovery but has an immediate impact on carbon dioxide and methane exchange. On the floating flux tower, we quantified annual carbon dioxide and methane exchange to inform future management. Our results suggested that the study area was a net carbon sink after 7-year rewetting.
Amy E. Pickard, Kate V. Heal, Andrew R. McLeod, and Kerry J. Dinsmore
Biogeosciences, 14, 1793–1809,Short summary
Peatland catchments export significant volumes of photoreactive carbon to aquatic systems, particularly headwater streams. Delivery of photoreactive material is subject to seasonal variation, and is also influenced by the timing and magnitude of rainfall events. We suggest that photoprocessing of peatland derived carbon may contribute to carbon dioxide emissions from aquatic systems, although considerable uncertainty remains as to how much material is processed
in situwithin these systems.
Eva van den Elzen, Martine A. R. Kox, Sarah F. Harpenslager, Geert Hensgens, Christian Fritz, Mike S. M. Jetten, Katharina F. Ettwig, and Leon P. M. Lamers
Biogeosciences, 14, 1111–1122,Short summary
Peatlands are important because they sequester large amounts of carbon, for which nitrogen is needed. In peatlands dominated by peat mosses, atmospheric nitrogen is fixed by associated microorganisms. We here show for the first time experimentally that phosphorus availability and acid buffering, both showing large variations among peatlands, can explain the strong differences reported for nitrogen fixation. This improves our understanding of peatland functioning in relation to global change.
Paul J. Hanson, Jeffery S. Riggs, W. Robert Nettles, Jana R. Phillips, Misha B. Krassovski, Leslie A. Hook, Lianhong Gu, Andrew D. Richardson, Donald M. Aubrecht, Daniel M. Ricciuto, Jeffrey M. Warren, and Charlotte Barbier
Biogeosciences, 14, 861–883,Short summary
This paper describes operational methods to achieve whole-ecosystem warming (WEW) for tall-stature, high-carbon, boreal forest peatlands. The methods enable scientists to study immediate and longer-term (1 decade) responses of organisms (microbes to trees) and ecosystem functions (carbon, water and nutrient cycles). The WEW technology allows researchers to have a plausible glimpse of future environmental conditions for study that are not available in the current observational record.
Yingying Tang, Sarah F. Harpenslager, Monique M. L. van Kempen, Evi J. H. Verbaarschot, Laury M. J. M. Loeffen, Jan G. M. Roelofs, Alfons J. P. Smolders, and Leon P. M. Lamers
Biogeosciences, 14, 755–766,Short summary
Aquatic macrophytes can be used for wastewater polishing but not for purification. At a low nutrient loading M. spicatum and A. filiculoides performed equally well for P removal, whereas at loads ≥ 22 mg P m−2 d−1, A. filiculoides removes P more efficiently. We provide an easily applicable method to select efficient macrophytes species for wastewater polishing, which is essential for decision support in water management using constructed wetlands for nutrient removal by plant harvesting.
Marijn Van de Broek, Stijn Temmerman, Roel Merckx, and Gerard Govers
Biogeosciences, 13, 6611–6624,Short summary
The results of this study on the organic carbon (OC) stocks of tidal marshes show that variations in OC stocks along estuaries are important and should be taken into account to make accurate estimates of the total amount of OC stored in these ecosystems. Moreover, our results clearly show that most studies underestimate the variation in OC stocks along estuaries due to a shallow sampling depth, neglecting the variation in OC decomposition after burial along estuaries.
Rémon Saaltink, Stefan C. Dekker, Jasper Griffioen, and Martin J. Wassen
Biogeosciences, 13, 4945–4957,Short summary
We identified biogeochemical plant–soil feedback processes that occur when oxidation, drying and modification by plants alter sediment conditions. Wetland construction in Markermeer (a lake in the Netherlands) is used as a case study. Natural processes will be utilized during and after construction to accelerate ecosystem development. We conducted a 6-month greenhouse experiment to identify the key biogeochemical processes in the mud when Phragmites australis is used as an eco-engineer.
Irina Evgenievna Terentieva, Mikhail Vladimirovich Glagolev, Elena Dmitrievna Lapshina, Alexandr Faritovich Sabrekov, and Shamil Maksyutov
Biogeosciences, 13, 4615–4626,Short summary
West Siberia (WS) wetlands are the world’s largest high-latitude wetland system. WS methane emission estimates suffered from large uncertainty due to high emission rate variability across the wetland vegetation cover. We mapped WS taiga zone wetlands with Landsat imagery and applied wetland typology specifically developed to reflect heterogeneity of methane fluxes. The map provides a benchmark for validation of coarse-resolution land cover products and wetland data sets in high latitudes.
Merten Minke, Jürgen Augustin, Andrei Burlo, Tatsiana Yarmashuk, Hanna Chuvashova, Annett Thiele, Annette Freibauer, Vitalij Tikhonov, and Mathias Hoffmann
Biogeosciences, 13, 3945–3970,Short summary
We studied GHG emissions along water-level gradients of two inundated cutover fens with closed chambers. N2O fluxes were negligible. CO2 and CH4 fluxes were controlled by vegetation composition and plant productivity, which in turn depended on water level and nutrient conditions. CH4 fluxes from mesotrophic sites were low and largely compensated for by CO2 uptake. Eutrophic sites were strong CH4 sources, and GHG balances depended on the plant's net C sink, which strongly differed between species.
Daniela Franz, Franziska Koebsch, Eric Larmanou, Jürgen Augustin, and Torsten Sachs
Biogeosciences, 13, 3051–3070,Short summary
Based on the eddy covariance method we investigate the ecosystem–atmosphere exchange of CH4 and CO2 at a eutrophic shallow lake as a challenging ecosystem often evolving during peatland rewetting. Both open water and emergent vegetation are net emitters of CH4 and CO2, but with strikingly different release rates. Even after 9 years of rewetting the lake ecosystem exhibits a considerable carbon loss and global warming impact, the latter mainly driven by high CH4 emissions from the open waterbody.
Lei Zhao, Christopher W. N Anderson, Guangle Qiu, Bo Meng, Dingyong Wang, and Xinbin Feng
Biogeosciences, 13, 2429–2440,
K. Zając and C. Blodau
Biogeosciences, 13, 707–722,Short summary
Peatlands have been exposed to nitrogen (N) deposition in Europe for decades. In this greenhouse study we investigated how N concentration and mobility in plants and peat have responded by sampling five sites across Europe and experimentally depositing labeled nitrogen on samples in a greenhouse. The peat moss retained its ability to absorb labeled nitrogen, but in the polluted sites more of it reached the deeper peat and was taken up by shrubs and grasses, indicating increased mobility of N.
R. L. Sobrinho, M. C. Bernardes, G. Abril, J.-H. Kim, C. I Zell, J.-M. Mortillaro, T. Meziane, P. Moreira-Turcq, and J. S. Sinninghe Damsté
Biogeosciences, 13, 467–482,Short summary
The principal objective of the present work is to quantify the fractions of the principal sources of sedimentary organic matter (SOM) in floodplain lakes of the central Amazon basin. The results indicate that the main source of SOM is not the riverine particulate material, as postulated by the literature, but the macrophytes and the forests.
A. L. Zuijdgeest, R. Zurbrügg, N. Blank, R. Fulcri, D. B. Senn, and B. Wehrli
Biogeosciences, 12, 7535–7547,Short summary
Two large floodplains hold the peak flows in the Zambezi River system – the dam-impacted Kafue Flats and the largely pristine Barotse Plains. Here we show that the inputs of organic matter and nutrients from such floodplains to the river are strongly affected by the presence of hydropower dams and highlight how floodplains act as large biogeochemical reactors that can behave distinctly differently from the entire catchment.
X. Chen, T. J. Bohn, and D. P. Lettenmaier
Biogeosciences, 12, 6259–6277,Short summary
We used a process-based model to investigate the sensitivities of pan-Arctic wetland methane emissions to climate factors, as a function of climate. Over the period 1960-2006, temperature was the dominant driver of trends in emissions. Wetlands north of 60N were temperature-limited, and wetlands south of 60N latitude were water-limited. Projected future warming will cause water-limited wetlands to expand northward over the next century, lessening the role of temperature in the future.
R. H. Bulmer, C. J. Lundquist, and L. Schwendenmann
Biogeosciences, 12, 6169–6180,Short summary
This is the first study investigating the effect of clearing on sediment CO2 efflux in temperate Avicennia marina forests. We found that rates of sediment CO2 efflux from cleared and intact temperate Avicennia marina forests are comparable to rates observed in other temperate and tropical forests. Our results show that greater consideration should be made regarding the rate of carbon released from mangrove forest following clearance and the relative contribution to global carbon emissions.
F. Cresto Aleina, B. R. K. Runkle, T. Kleinen, L. Kutzbach, J. Schneider, and V. Brovkin
Biogeosciences, 12, 5689–5704,Short summary
We developed a process-based model for peatland micro-topography and hydrology, the Hummock-Hollow (HH) model, which explicitly represents small-scale surface elevation changes. By coupling the HH model with a model for soil methane processes, we are able to model the effects of micro-topography on hydrology and methane emissions in a typical boreal peatland. We also identify potential biases that models without a micro-topographic representation can introduce in large-scale models.
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