Global carbon exchange and methane emissions from natural wetlands : Application of a process-based model

Wetlands are one of the most important sources of atmospheric methane (CH 4 ), but the strength of this source is still highly uncertain. To improve estimates of CH 4 emission at the regional and global scales and predict future variation requires a process-based model integrating the controls of climatic and edaphic factors and complex biological processes over CH 4 flux rates. This study used a methane emission model based on the hypothesis that plant primary production and soil organic matter decomposition act to control the supply of substrate needed by methanogens ; the rate of substrate supply and environmental factors, in turn, control the rate of CH 4 production, and the balance between CH 4 production and methanotrophic oxidation determines the rate of CH 4 emission into the atmosphere. Coupled to data sets for climate, vegetation, soil, and wetland distribution, the model was used to calculate spatial and seasonal distributions of CH 4 emissions at a resolution of 1° latitude x 1° longitude. The calculated net primary production (NPP) of wetlands ranged from 45 g C m -2 yr -1 for northern bogs to 820 g C m -2 yr -1 for tropical swamps. CH 4 emission rates from individual gridcells ranged from 0.0 to 661 mg CH 4 m -2 d -1 , with a mean of 40 mg CH 4 m -2 d -1 for northern wetland, 150 mg CH 4 m -2 d -1 for temperate wetland, and 199 mg CH 4 m -2 d -1 for tropical wetland. Total CH 4 emission was 92 Tg yr -1 . Sensitivity analysis showed that the response of CH 4 emission to climate change depends upon the combined effects of soil carbon storage, rate of decomposition, soil moisture and activity of methanogens.

[1]  E. Rastetter,et al.  Potential Net Primary Productivity in South America: Application of a Global Model. , 1991, Ecological applications : a publication of the Ecological Society of America.

[2]  P. M. Lang,et al.  Slowing down of the global accumulation of atmospheric methane during the 1980s , 1992, Nature.

[3]  Henning Rodhe,et al.  A Comparison of the Contribution of Various Gases to the Greenhouse Effect , 1990, Science.

[4]  J. Lerner,et al.  Three‐dimensional model synthesis of the global methane cycle , 1991 .

[5]  P. Lafleur,et al.  Northern fens: methane flux and climatic change , 1992 .

[6]  H. Schütz,et al.  Temperature limitation of hydrogen turnover and methanogenesis in anoxic paddy soil , 1987 .

[7]  Barrie Maxwell,et al.  2 – Arctic Climate: Potential for Change under Global Warming , 1992 .

[8]  S. McNaughton,et al.  Ecotype Function in the Typha Community‐Type , 1966 .

[9]  B. Svensson.  Carbon fluxes from acid peat of a subarctic mire with emphasis on methane , 1983 .

[10]  R. Knowles,et al.  Methane emissions from fen, bog and swamp peatlands in Quebec , 1990 .

[11]  J. Servant,et al.  Methane emission from flooded forest in central Africa , 1992 .

[12]  W. Reeburgh,et al.  Interannual variations in tundra methane emission: A 4-year time series at fixed sites , 1992 .

[13]  D. I. Sebacher,et al.  Methane emissions to the atmosphere through aquatic plants , 1985 .

[14]  R. A. Burke,et al.  Methane flux and stable hydrogen and carbon isotope composition of sedimentary methane from the Florida Everglades , 1988 .

[15]  Helmut Schütz,et al.  Processes involved in formation and emission of methane in rice paddies , 1989 .

[16]  R. A. Burke,et al.  Diffusive flux of methane from warm wetlands , 1988 .

[17]  F. Stuart Chapin,et al.  Environmental and biotic controls over methane flux from Arctic tundra , 1993 .

[18]  D. I. Sebacher,et al.  Sources of atmospheric methane in the south Florida environment , 1988 .

[19]  W. Whitman,et al.  Methanogens and the diversity of archaebacteria. , 1987, Microbiological reviews.

[20]  W. Cramer,et al.  The IIASA database for mean monthly values of temperature , 1991 .

[21]  W. Reeburgh,et al.  Consumption of atmospheric methane by tundra soils , 1990, Nature.

[22]  R. Knowles,et al.  Spatial and temporal variations of methane flux from subarctic/northern boreal fens , 1990 .

[23]  D. Schimel,et al.  Ecosystem and physiological controls over methane production in northern wetlands , 1994 .

[24]  D. Lashof,et al.  Relative contributions of greenhouse gas emissions to global warming , 1990, Nature.

[25]  H. Hemond,et al.  Methane transport and oxidation in the unsaturated zone of a Sphagnum peatland , 1992 .

[26]  R. Sass,et al.  Methane production and emission in a Texas rice field , 1990 .

[27]  A. McGuire,et al.  Interactions between carbon and nitrogen dynamics in estimating net primary productivity for potential vegetation in North America , 1992 .

[28]  Eville Gorham,et al.  Methane flux from Minnesota Peatlands , 1988 .

[29]  D. I. Sebacher,et al.  Methane flux from northern peatlands , 1985, Nature.

[30]  W. Pulliam.  Carbon Dioxide and Methane Exports from a Southeastern Floodplain Swamp , 1993 .

[31]  Luiz Antonio Martinelli,et al.  Seasonal dynamics in methane emissions from the Amazon River floodplain to the troposphere , 1990 .

[32]  W. Oechel,et al.  Simulating carbon accumulation in northern ecosystems , 1983 .

[33]  Tim R. Moore,et al.  THE INFLUENCE OF WATER TABLE LEVELS ON METHANE AND CARBON DIOXIDE EMISSIONS FROM PEATLAND SOILS , 1989 .

[34]  G. King,et al.  Distribution and Rate of Methane Oxidation in Sediments of the Florida Everglades , 1990, Applied and environmental microbiology.

[35]  J. Chanton,et al.  Quantification of methane oxidation in the rhizosphere of emergent aquatic macrophytes: defining upper limits , 1993 .

[36]  P. Westermann.  Temperature regulation of methanogenesis in wetlands , 1993 .

[37]  Paul J. Crutzen,et al.  Global distribution of natural freshwater wetlands and rice paddies, their net primary productivity, seasonality and possible methane emissions , 1989 .

[38]  Leslie A. Morrissey,et al.  Methane emissions from Alaska Arctic tundra: An assessment of local spatial variability , 1992 .

[39]  D. Chynoweth,et al.  The contributions of temperature and of the input of organic matter in controlling rates of sediment methanogenesis1 , 1981 .

[40]  J. Chanton,et al.  3 – Effects of Vegetation on Methane Flux, Reservoirs, and Carbon Isotopic Composition , 1991 .

[41]  G. Velde,et al.  Root aerenchyma, oxygen leakage patterns and alcoholic fermentation ability of the roots of some nymphaeid and isoetid macrophytes in relation to the sediment type of their habitat , 1990 .

[42]  J. Chanton,et al.  Primary production control of methane emission from wetlands , 1993, Nature.

[43]  N. Dise,et al.  Environmental Factors Controlling Methane Emissions from Peatlands in Northern Minnesota , 1993 .

[44]  A. McGuire,et al.  Global climate change and terrestrial net primary production , 1993, Nature.

[45]  J. Yavitt,et al.  Methane consumption in two temperate forest soils , 1990 .

[46]  T. Moore,et al.  A preliminary investigation of primary production and decomposition in four peatlands near Schefferville, Québec , 1985 .

[47]  D. Schimel,et al.  Control of methane production in terrestrial ecosystems. , 1989 .

[48]  A. Heyes,et al.  Methane emissions from wetlands, southern Hudson Bay lowland , 1994 .

[49]  Luiz Antonio Martinelli,et al.  Methane emissions to the troposphere from the Amazon floodplain , 1988 .

[50]  E. Baradziej.  Net primary production of two marsh communities near Ispinain the Niepolomice forest (southern Poland) , 1974 .

[51]  Torben R. Christensen,et al.  Methane emission from Arctic tundra , 1993 .

[52]  A. G. Valk,et al.  Hydrarch succession and net primary production of oxbow lakes in central Alberta , 1971 .

[53]  K. Yagi,et al.  Effect of Organic Matter Application on Methane Emission from Some Japanese Paddy Fields , 1990 .

[54]  W. Reeburgh,et al.  A methane flux time series for tundra environments , 1988 .

[55]  F. Ponnamperuma,et al.  Behavior of anaerobic decomposition products in submerged soils, effects of organic material amendment, soil properties, and temperature. , 1987 .

[56]  D. Etheridge,et al.  Evidence of changing concentrations of atmospheric CO2, N2O and CH4 from air bubbles in Antarctic ice , 1986, Nature.

[57]  P. Crill,et al.  Methane emissions from tundra environments in the Yukon‐Kuskokwim delta, Alaska , 1992 .

[58]  J. Yavitt,et al.  Control of carbon mineralization to CH4 and CO2 in anaerobic,Sphagnum-derived peat from Big Run Bog, West Virginia , 1987 .

[59]  W. Oechel,et al.  The effect of soil moisture and thaw depth on CH4 flux from wet coastal tundra ecosystems on the north slope of Alaska , 1993 .

[60]  T. Rosswall,et al.  In situ methane production from acid peat in plant communities with different moisture regimes in a subarctic mire , 1984 .

[61]  P. Warnant,et al.  CARAIB - A global model of terrestrial biological productivity , 1994 .

[62]  S. Frolking,et al.  Climate controls on temporal variability of methane flux from a poor fen in southeastern New Hampshire: Measurement and modeling , 2019 .

[63]  D. I. Sebacher,et al.  Methane flux in forested freshwater swamps of the southeastern United States , 1981 .

[64]  J. Chanton,et al.  Stable isotopes as tracers of methane dynamics in Everglades marshes with and without active populations of methane oxidizing bacteria , 1993 .

[65]  D. Jacob,et al.  Micrometeorological measurements of CH4 and CO2 exchange between the atmosphere and subarctic tundra , 1992 .

[66]  D. I. Sebacher,et al.  Atmospheric methane sources: Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh , 1986 .

[67]  P. Dunfield,et al.  Methane production and consumption in temperate and subarctic peat soils: Response to temperature and pH , 1993 .

[68]  T. Callaghan,et al.  Spatial variation in high‐latitude methane flux along a transect across Siberian and European tundra environments , 1995 .

[69]  P. Crill,et al.  Methane flux from the Amazon River floodplain: Emissions during rising water , 1990 .

[70]  J. Chanton,et al.  Plant‐dependent CH4 emission in a subarctic Canadian fen , 1992 .

[71]  C. W. Thornthwaite.  An approach toward a rational classification of climate. , 1948 .

[72]  Inez Y. Fung,et al.  Methane emission from natural wetlands: Global distribution, area, and environmental characteristics of sources , 1987 .

[73]  N. Matveyeva,et al.  4 – Circumpolar Arctic Vegetation , 1992 .

[74]  Robert C. Harriss,et al.  Review and assessment of methane emissions from wetlands , 1993 .