This work presents a review of the main processes leading to the production and sinking of methane in wetlands and how they affect the stable isotope composition of carbon and hydrogen. Isotope fractionation factors associated to diffusion, ebullition, bacterial oxidation, etc., have been gathered from relevant literature in an intent of providing researchers in this thematic with practical procedures and tools for the interpretation of experimental data. Also it is presented guidelines of the most reliable field and laboratory methods used at present for the correct sampling and analyzing methane in different stages of occurrence, as well the most common tools used in their interpretation. Each statement is fully referenced to a long updated list of publications.
KeywordsC and H Stable IsotopesCH<sub>4</sub>and CO<sub>2</sub>EmissionsWetlands
IPCC (2015) Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, IPCC, Geneva.
Kirschke, S., Bousquet, P., Ciais, P., Saunois, M., Canadell, J.G., Dlugokencky, E.J., et al. (2013) Three Decades of Global Methane Sources and Sinks. Nature Geoscience, 6, 813-823. http://dx.doi.org/10.1038/ngeo1955
Stenke, A., Deckert, R. and Gottschaldt, K. (2012) Methane modeling: From Process Modeling to Global Climate Models. In: Schumann, U., Ed., Atmospheric Physics: Background-Methods-Trends, Springer, Berlin, 781-797, http://dx.doi.org/10.1007/978-3-642-30183-4_47
IPCC (2007) The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the intergovernmental Panel on Climate Change. In: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., Miller, H.L., Eds., Climate Change 2007, Cambridge University Press, Cambridge and New York, 996.
Keppler, F., Hamilton, J.T.G., Brab, M. and Rockmann, T. (2006) Methane Emissions from Terrestrial Plants under Aerobic Conditions. Nature, 439, 187-191. http://dx.doi.org/10.1038/nature04420
Mikaloff Fletcher, S.E., Tans, P.P., Bruhwiler, L.M., Miller, J.B. and Heimann, M. (2004) CH4 Source Estimated from Atmospheric Observations of CH4 and Its 13C/12C Isotopic Ratios: 1. Inverse Modeling of Source Processes. Global Biogeochemical Cycles, 18, Article ID: GB4004.
Mikaloff Fletcher, S.E., Tans, P.P., Bruhwiler, L.M., Miller, J.B. and Heimann, M. (2004) CH4 Source Estimated from Atmospheric Observations of CH4 and Its 13C/12C Isotopic Ratios: 2. Inverse Modeling of CH4 Fluxes from Geographic Regions. Global Biogeochemical Cycles, 18, Article ID: GB4004.
Bousquet, P., Ciais, P., Miller, J.B., Dlugokencky, E.J., Hauglustaine, D.A., Prigent, C., et al. (2006) Contribution of Anthropogenic and Natural Sources to Atmospheric Methane Variability. Nature, 443, 439-443. http://dx.doi.org/10.1038/nature05132
Chen, Y.-H. and Prinn, R.G. (2006) Estimation of Atmospheric Methane Emissions between 1996 and 2001 Using a Three-Dimensional Global Chemical Transport Model. Journal of Geophysical Research, 111, Article ID: D10307. http://dx.doi.org/10.1029/2005jd006058
Neef, L., van Weele, M. and van Velthoven, P. (2010) Optimal Estimation of the Present-Day Global Methane Budget. Global Biogeochemical Cycles, 24, Article ID: GB4024. http://dx.doi.org/10.1029/2009gb003661
Whiticar, M.J., Faber, E. and Schoell, M. (1986) Biogenic Methane Formation in Marine and Freshwater Environments: CO2 Reduction vs. Acetate Fermentation—Isotope Evidence. Geochimica et Cosmochimica Acta, 50, 693-709. http://dx.doi.org/10.1016/0016-7037(86)90346-7
Conrad, R. (1989) Control of Methane Production in Terrestrial Ecosystems, In: Andreae, M.O. and Schimel, D.S., Ed., Exchange of Trace Gases between Terrestrial Ecosystems and the Atmosphere, John Wiley, New York, 39-58.
Whiticar, M.J. (1999) Carbon and Hydrogen Isotope Systematics of Bacterial Formation and Oxidation of Methane. Chemical Geology, 161, 291-314. http://dx.doi.org/10.1016/S0009-2541(99)00092-3
Monteil, G., Houweling, S., Dlugockenky, E.J., Maenhout, G., Vaughn, B.H., White, J.W. and Rockmann, T. (2011) Interpreting Methane Variations in the Past Two Decades Using Measurements of CH4 Mixing Ratio and Isotopic Composition. Atmospheric Chemistry and Physics, 11, 9141-9153. http://dx.doi.org/10.5194/acp-11-9141-2011
Fisher, R.E., Sriskantharajah, S., Lowry, D., Lanoiselle, M., Fowler, C.M.R., et al. (2011) Arctic Methane Sources: Isotopic Evidence for Atmospheric Inputs. Geophysical Research Letters, 38, Article ID: L21803. http://dx.doi.org/10.1029/2011gl049319
Khalil, M. (2000) Atmospheric Methane. Springer, New York. http://dx.doi.org/10.1007/978-3-662-04145-1
Wuebbles, D.J. and Hayhoe, K. (2002) Atmospheric Methane and Global Change. Earth-Science Reviews, 57, 177-210. http://dx.doi.org/10.1016/S0012-8252(01)00062-9
EPA (2001) Environmental Protection Agency of United States, Office of Water EPA 843-F-01-002b, Oceans and Watersheds (4502T). http://water.epa.gov/type/wetlands/types_index.cfm
MacDonald, J.A., Fowler, D., Hargreaves, K.J., Skiba, U., Leith, I.D. and Murray, M.B. (1998) Methane Emission Rates from a Northern Wetland: Response to Temperature, Water Table and Transport. Atmospheric Environment, 32, 3219-3227. http://dx.doi.org/10.1016/s1352-2310(97)00464-0
Christensen, T.R., Panikov, N., Mastepanov, M., Joabsson, M.A., Stewart, A., ?quist, M., Sommerkorn, M., Reynaud, S. and Svensson, B. (2003) Biotic Controls on CO2 and CH4 Exchange in Wetlands—A Closed Environment Study. Biogeochemistry, 64, 337-354. http://dx.doi.org/10.1023/A:1024913730848
Olson, D.M., Griffis, T.J., Noormets, A., Kolka, R. and Chen, J. (2013) Interannual, Seasonal, and Retrospective Analysis of the Methane and Carbon Dioxide Budgets of a Temperate Peatland. Journal of Geophysical Research: Biogeosciences, 118, 226-238. http://dx.doi.org/10.1002/jgrg.20031
Le Mer, J. and Roger, P. (2001) Production, Oxidation, Emission and Consumption of Methane by Soils: A Review. European Journal of Soil Biology, 37, 25-50. http://dx.doi.org/10.1016/S1164-5563(01)01067-6
Whalen, S.C. (2005) Biogeochemistry of Methane Exchange between Natural Wetlands and the Atmosphere. Environmental Engineering Science, 22, 73-94. http://dx.doi.org/10.1089/ees.2005.22.73
Lai, D.Y. (2009) Methane Dynamics in Northern Peatlands: A Review. Pedosphere, 19, 409-421. http://dx.doi.org/10.1016/S1002-0160(09)00003-4
Baird, A., Belyea, L.R., Comas, X., Reeve A.S. and Slater, L.D. (2013) Carbon Cycling in Northern Peatlands. American Geophysical Union (AGU), Washington DC.
Glaser, P.H., Chanton, J.P., Morin, P., Rosenberry, D.O., Siegel, D.I., Ruud, O., Chasar, L.I. and Reeve, A.S. (2004) Surface Deformations as Indicators of Deep Ebullition Fluxes in a Large Northern Peatland. Global Biogeochemical Cycles, 18, Article ID: GB1003. http://dx.doi.org/10.1029/2003gb002069
Clark, I.D. and Fritz, P. (1997) Environmental Isotopes in Hydrogeology. Lewis Publishers, New York.
Coleman, D.D., Liu, C.L., Hackley, K.C. and Benson, L.J. (1993) Identification of Landfill Methane Using Carbon and Hydrogen Isotope Analysis. Proceedings of 16th International Madison Waste Conference, Municipal & Industrial Waste, Department of Engineering Professional Development, University of Wisconsin Madison, Madison, 22-23 September 1993, 303-314.
Hackley, K.C., Coleman, D.D. and Liu, C.L. (1996) Environmental Isotope Characteristics of Landfill Leachates and Gases. Groundwater, 34, 827-836. http://dx.doi.org/10.1111/j.1745-6584.1996.tb02077.x
Conrad, R. (2005) Quantification of Methanogenic Pathways Using Stable Carbon Isotopic Signatures: A Review and a Proposal. Organic Geochemistry, 36, 739-752. http://dx.doi.org/10.1016/j.orggeochem.2004.09.006
Megonigal, J.P., Hines, M.E. and Visscher, P.T. (2004) Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes. In: Schlesinger, W.H., Ed., Biogeochemistry, Elsevier-Pergamon, Oxford, 317-424.
Hornibrook, E.R.C, Longstae, W.S. and Fyfe, W.S. (1997) Spatial Distribution of Microbial Methane Production Pathways in Temperate Zone Wetland Soils: Stable Carbon and Hydrogen Isotope Evidence. Geochimica et Cosmochimica Acta, 61, 745-753.
Dorodnikov, M., Marushchak, M., Biasi, C. and Wilmking, M. (2013) Effect of Microtopography on Isotopic Composition of Methane in Porewater and Efflux at a Boreal Peatland. Boreal Environment Research, 18, 269-279.
Walter, K.M., Chanton, J.P., Chapin, F.S., Schuur, E.A. and Zimov, S.A. (2008) Methane Production and Bubble Emissions from Arctic Lakes: Isotopic Implications for Source Pathways and Ages. Journal of Geophysical Research, 113, Article ID: G00A08. http://dx.doi.org/10.1029/2007JG000569
Yamamoto, S., Alcauskas, J.B. and Crozier, T.E. (1976) Solubility of Methane in Distilled Water and Seawater. Journal of Chemical & Engineering Data, 21, 78-80. http://dx.doi.org/10.1021/je60068a029
Simpkins, W.W. and Parkin T.B. (1993) Hydrogeology and Redox Geochemistry of Methane in a Late Wisconsinan Till and Loess Sequence in Central Iowa. Water Resources Research, 29, 3643-3657. http://dx.doi.org/10.1029/93WR01687
Beckwith, C.W. and Baird, A.J. (2001). Effect of Biogenic Gas Bubbles on Water Flow through Poorly Decomposed Blanket Peat. Water Resources Research, 37, 551-558. http://dx.doi.org/10.1029/2000WR900303
Baird, A.J. and Waldron, S. (2003). Shallow Horizontal Groundwater Flow in Peatlands Is Reduced by Bacteriogenic Gas Production. Geophysical Research Letters, 30, Article No. 2043. http://dx.doi.org/10.1029/2003GL018233
Strack, M., Kellner, E. and Waddington, J.M. (2005) Dynamics of Biogenic Gas Bubbles in Peat and Their Effects on Peatland Biogeochemistry. Global Biogeochemical Cycles, 19, Article ID: GB1003. http://dx.doi.org/10.1029/2004GB002330
Kellner, E., Baird, A.J., Oosterwoud, M., Harrison, K. and Waddington, J.M. (2006) Effect of Temperature and Atmospheric Pressure on Methane (CH4) Ebullition from Near-Surface Peats. Geophysical Research Letters, 33, Article ID: L18405. http://dx.doi.org/10.1029/2006GL027509
Comas, X., Slater, L. and Reeve, A. (2005). Spatial Variability in Biogenic Gas Accumulations in Peat Soils Is Revealed by Ground Penetrating Radar (GPR). Geophysical Research Letters, 32, Article ID: L08401. http://dx.doi.org/10.1029/2004gl022297
Tokida, T., Miyazaki, T., Mizoguchi, M., Nagata, O., Takakai, F., Kagemoto, A. and Hatano, R. (2007) Falling Atmospheric Pressure as a Trigger for Methane Ebullition from a Peatland. Global Biogeochemical Cycles, 21, Article ID: GB2003. http://dx.doi.org/10.1029/2006GB002790
Beckmann, M., Sheppard, S.K. and Lloyd, D. (2004) Mass Spectrometric Monitoring of Gas Dynamics in Peat Monoliths: Effects of Temperature and Diurnal Cycles on Emissions. Atmospheric Environment, 38, 6907-6913. http://dx.doi.org/10.1016/j.atmosenv.2004.08.004
Fechner-Levy, E.J. and Hemond, H.F. (1996) Trapped Methane Volume and Potential Effects on Methane Ebullition in a Northern Peatland. Limnology and Oceanography, 41, 1375-1383. http://dx.doi.org/10.4319/lo.1996.41.7.1375
Coulthard, T.J., Baird, A.J., Ramirez, J. and Waddington, J.M. (2009) Methane Dynamics in Peat: Importance of Shallow Peats and a Novel Reduced-Complexity Approach for Modeling Ebullition. In: Carbon Cycling in Northern Peatlands. Geophysical Monograph Series, 184, 173-185. http://dx.doi.org/10.1029/2008gm000811
Siegel, D.I., Chanton, J.E., Glaser, E.H., Chasar, L.C. and Rosenberry, D.O. (2001) Estimating Methane Production Rates in Bogs and Landfills by Deuterium Enrichment of Pore-Water. Global Biogeochemical Cycles, 15, 967-977. http://dx.doi.org/10.1029/2000GB001329
Romanowicz, E.A., Siegel, D.I., Chanton, J.P. and Glaser, P.H. (1995) Temporal Variations in Dissolved Methane Deep in the Lake Agassiz Peatlands, Minnesota. Global Biogeochemical Cycles, 9, 197-212. http://dx.doi.org/10.1029/95GB00634
Walter, B.P., Heimann, M. and Matthews, E. (2001) Modeling Modern Methane Emissions from Natural Wetlands: 1. Model Description and Results. Journal of Geophysical Research, 106, 34189-34206. http://dx.doi.org/10.1029/2001JD900165
De Visscher, A., De Pourcq, I. and Chanton, J. (2004) Isotope Fractionation Effects by Diffusion and Methane Oxidation in Landfill Cover Soils. Journal of Geophysical Research, 109, Article ID: D18111. http://dx.doi.org/10.1029/2004jd004857
Happell, J.D., Chanton, J.P. and Showers, W.J. (1995) Methane Transfer across the Water-Air Interface in Stagnant Wooded Swamps of Florida: Evaluation of Mass-Transfer Coefficients and Isotopic Fractionation. Limnology and Oceanography, 40, 290-298. http://dx.doi.org/10.4319/lo.1995.40.2.0290
Chanton, J.P., Martens, C.S., Kelley, C.A., Crill, P.M. and Showers, W.J. (1992) Methane Transport Mechanisms and Isotope Fractionation in Emergent Macrophytes of an Alaskan Tundra Lake. Journal of Geophysical Research, 97, 16681-16688. http://dx.doi.org/10.1029/90JD01542
Bhullar, G.S., Iravani, M., Edwards, P.J. and Venterink, H.O. (2013) Methane Transport and Emissions from Soil as Affected by Water Table and Vascular Plants. BMC Ecology, 13, 32. http://dx.doi.org/10.1186/1472-6785-13-32
Chanton, J.P. (2005) The Effect of Gas Transport on the Isotope Signature of Methane in Wetlands. Organic Geochemistry, 36, 753-768. http://dx.doi.org/10.1016/j.orggeochem.2004.10.007
Bergamaschi, P. (1997) Seasonal Variation of Stable Hydrogen and Carbon Isotope Ratios in Methane from a Chinese Rice Paddy. Journal of Geophysical Research, 102, 25383-25393. http://dx.doi.org/10.1029/97JD01664
Coleman, D.D., Risatti, J.B. and Schoell, M. (1981) Fractionation of Carbon and Hydrogen Isotopes by Methane-Oxidizing Bacteria. Geochimica et Cosmochimica Acta, 45, 1033-1037. http://dx.doi.org/10.1016/0016-7037(81)90129-0
Gebert, J., Streblow, C. and Pfeiffer, E.M. (2011) Impact of Gas Transport on Fractionation of Carbon Stable Isotope Related to the Microbial Oxidation of Methane in Soils. EGU General Assembly. Geophysical Research Abstracts, 13, Article No. 14108.
Happell, J., Chanton, J.P. and Showers, W. (1994) The Influence of Methane Oxidation on the Stable Isotope Composition of Methane Emitted from Florida Swamp Forests. Geochimica et Cosmochimica Acta, 58, 4377-4388. http://dx.doi.org/10.1016/0016-7037(94)90341-7
Sanci, R., Panarello, H. and Ostera, H. (2009) Assessment of Soil Moisture Influence on CO2 Flux: A Laboratory Experiment. Environmental Geology, 58, 491-497. http://dx.doi.org/10.1007/s00254-008-1522-7
Sanci, R., Panarello, H. and Ostera, H. (2012) CO2 Emissions from a Municipal Site for Final Disposal of Solid Waste in Gualeguaychú, Entre Ríos Province, Argentina. Environmental Earth Sciences, 66, 519-528. http://dx.doi.org/10.1007/s12665-011-1260-0
Wassmann, R., Neue, H.U., Alberto, M.C.R., Lantin, R.S. Bueno, C., Llenaresas, D., Arah, J.R.M., Papen, H., Seiler, W. and Rennenberg, H. (1996) Fluxes and Pools of Methane in Wetlands Rices Oils with Varying Organic Inputs. Environmental Monitoring and Assessment, 42, 163-173. http://dx.doi.org/10.1007/BF00394048
McAuliffe, C. (1971) Gas Chromatographic Determination of Solutes by Multiple Phase Equilibrium. Chemical Technology, 1, 46-51.
Gonfiantini, R. (1978) Standards for Stable Isotope Measurements in Natural Compounds. Nature, 271, 534-536. http://dx.doi.org/10.1038/271534a0
Coplen, T. (1994) Reporting of Stable Hydrogen, Carbon, and Oxygen Isotopic Abundances. Pure and Applied Chemistry, 66, 273-276. http://dx.doi.org/10.1351/pac199466020273