Abstract
Elevated CO2 has been shown to increase methane emissions in herbaceous wetlands, but it is not clear that this will occur in wetlands dominated by woody plants or in wetlands that are not inundated. We determined the effects of elevated CO2 and water table position on methane emission and oxidation rates from plant-soil microcosms planted with a woody tree, Taxodium distichum, or an emergent aquatic macrophyte, Orontium aquaticum. Experiments were conducted in replicate glasshouses (n = 2) at CO2 concentrations of either 350 or 700 ppmv. Plants were grown from seed and subjected to two water level depths, flooded (+5 cm above the soil surface) and non-flooded (−10 cm for T. distichum and −6 cm for O. aquaticum). Elevated CO2 increased whole-plant photosynthetic rates in both water table treatments. Methane emission rates increased by 62 to 69% in the T. distichum treatment and 27 to 29% in the O. aquaticum treatment. Whole-plant photosynthesis and biomass were strongly correlated with methane emissions (r2≥ 0.75, P ≤ 0.01). This relationship provides evidence of a tight coupling between plant and microbial activity and suggests that similar relationships from other wetland studies measured at ambient CO2 can be extrapolated into the future. In the O. aquaticum, non-flooded treatment, methanotrophy consumed 14 and 22% (replicate glasshouses) of the methane produced in the ambient treatment compared to 29 and 36% in the elevated CO2 treatment. However, there was no significant methane oxidation detected in the flooded treatment. We concluded that woody and non-woody wetland ecosystems growing in a future CO2-enriched atmosphere will emit more methane regardless of water table position, but the degree of stimulation will be sensitive to changes in water table position, particularly in forested wetlands.
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References
Aerts R. and Caluwe H. 1999. Nitrogen deposition effects on carbon dioxide and methane emissions from temperate peatland soils. Oikos 84: 44-54.
Armstrong J. and Armstrong W. 2001. Rice and Phragmites: Effects of organic acids on growth, root permeability, and radial oxygen loss to the rhizospere. Am. J. Bot. 88: 1359-1370.
Ball A.S. 1997. Microbial decomposition at elevated CO2 levels: effect of litter quality. Global Change Biol. 3: 379-386.
Calhoun A. and King G.M. 1997. Regulation of root-associated methanotrophy by oxygen availability in the rhizosphere of two aquatic macrophytes. Applied and Environ. Microbiol. 63: 3051-3058.
Chanton J.P. and Dacey J.W.H. 1991. Effects of vegetation on methane flux, reservoirs, and carbon isotopic composition. In: Sharkey T.D., Holland E.A. and Mooney H.A. (eds), Trace Gas Emissions by Plants. Academic Press, San Diego, pp. 65-92.
Chanton J.P., Whiting G.J., Showers W.J. and Crill P.M. 1992. Methane flux from Peltandra virginica: Stable isotope tracing and chamber effects. Global Biogeochem. Cycles 6: 15-31.
Curtis P.S. 1996. A meta-analysis of leaf gas exchange and nitrogen in trees grown under elevated carbon dioxide. Plant Cell Environ. 19: 127-137.
Dacey J.W.H., Drake B.G. and Klug M.J. 1994. Stimulation of methane emission by carbon dioxide enrichment of marsh vegetation. Nature 370: 47-49.
Day R.W. and Quinn G.P. 1989. Comparisons of treatments after an analysis of variance in ecology. Ecol. Monogr. 59: 433-463.
Delucia E.H., Hamilton J.G., Naidu S.L., Thomas R.B., Andrews J.A., Finzi A. et al. 1999. Net primary production of a forest ecosystem with experimental CO2 enrichment. Science 284: 1177-1179.
Dhillion S.S., Roy J. and Abrams M. 1996. Assessing the impact of elevated CO2 on soil microbial activity in a Mediterranean model ecosystems. Plant Soil 187: 333-342.
Epp M.A. and Chanton J.P. 1993. Rhizospheric methane oxidation determined via the methyl-fluoride inhibition technique. J Geophys Res-Atmos 98: 18413-18422.
Grosse W., Frye J. and Lattermann S. 1992. Root aeration in wetland trees by pressurized gas transport. Tree Physiology 10: 285-295.
Hefner J.M. and Brown J.D. 1985. Wetland trends in southeastern United States. Wetlands 4: 1-11.
Hook D.D. and Brown C.L. 1971. Permeability of the cambium to air in trees adapted to wet habitats. Bot. Gaz. 133: 304-310.
Huang Y., Sass R.L. and Fisher F.M. 1998. A semi-empirical model of methane emission from flooded rice paddy soils. Global Change Biol. 4: 247-268.
Hutchin P.R., Press M.C., Lee J.A. and Ashenden T.W. 1995. Elevated concentrations of CO2 may double methane emissions from mires. Global Change Biol. 1: 125-128.
Jacob J., Greitner C. and Drake B.G. 1995. Acclimation of photosynthesis in relation to rubisco and non-structural carbohydrate contents and in situ carboxylase activity in Scirpus olneyi grown at elevated CO2 in the field. Plant Cell Environ. 18: 875-884.
Kattenburg A., Giorgi F., Grassl H., Meehl G.A., Mitchell J.B.F., Stouffer R.J. et al. 1995. Climate models-projections of future climate. In: Houghton J.T., Meira Filho L.G., Callander B.A., Harris N., Kattenburg A. and Maskell K. (eds), Intergovernmental Panel on Climate Change. Cambridge University Press, New York, pp. 290-349.
Matthews E. and Fung I. 1987. Methane emission from natural wetlands: Global distribution, area, and environmental characteristics of sources. Global Biogeoch. Cycles 1: 61-86.
Mattoon W.R. 1915. The Southern Cypress. Bulletin 272. US Department of Agriculture.
Megonigal J.P. 1996. Methane production and oxidation in a future climate. PhD Dissertation, Duke University, Durham, USA.
Megonigal J.P. and Day F.P. 1992. Effects of flooding on root and shoot production of bald cypress in large experimental enclosures. Ecology 73: 1182-1193.
Megonigal J.P. and Schlesinger W.H. 1997. Enhanced CH4 emissions from a wetland soil exposed to elevated CO2. Biogeochemistry 37: 77-88.
Megonigal J.P., Whalen S.C., Tissue D.T., Bovard B.D., Albert D.B. and Allen A.S. 1999. A plant-soilatmosphere microcosm for tracing radiocarbon from photosynthesis through methanogenesis. Soil Sci. Soc. Am. J. 63: 665-671.
Mindota T. and Kimura M. 1994. Contribution of photosynthesized carbon to the methane emitted from paddy fields. Geophys. Res. Lett. 21: 2007-2010.
Mindota T. and Kimura M. 1996. Photosynthates as dominant source of CH4 and CO2 in soil water and CH4 emitted to the atmosphere from paddy fields. J. Geophys. Res. 101: 21091-21097.
Oren R., Ellsworth D.S., Johnsen K.H., Phillips N., Ewers B.E., Maier C. et al. 2001. Soil fertility limits carbon sequestration by forest ecosystems in a CO2-enriched atmosphere. Nature 411: 469-472.
Paterson E. et al. 1997. Effect of elevated CO2 on rhizosphere carbon flow and soil microbial processes. Global Change Biol. 3: 363-377.
Pezeshki S.R. 1991. Root responses of flood-tolerant and flood-sensitive tree species to soil redox conditions. Trees 5: 180-186.
Pulliam W.M. 1992. Methane emissions from cypress knees in a southeastern floodplain swamp. Oecologia 91: 126-128.
Rusch H. and Rennenberg H. 1998. Black alder (Alnus glutinosa (L.) Gaertn.) trees mediate methane and nitrous oxide emission from the soil to the atmosphere. Plant Soil 201: 1-7.
Sadowsky M.J. and Schortemeyer M. 1997. Soil microbial responses to increased concentrations of atmospheric CO2. Global Change Biol. 3: 217-224.
Saarino S., Alm J., Martikainen P.J. and Silvola J. 1998. Effects of raised CO2 on potential CH4 production and oxidation in, and CH4 emission from, a boreal mire. J. Ecology 86: 261-268.
Saarino S. and Silvola J. 1999. Effects of increased CO2 and N on CH4 efflux from a boreal mire: a growth chamber experiment. Oecologia 119: 349-356.
SAS Institute 1987. SAS/STAT guide for personal computers, Version. SAS Institute, Cary, NC, USA.
Schrope M.K., Chanton J.P., Allen L.H. and Baker J.T. 1999. Effect of CO2 enrichment and elevated temperature on methane emissions from rice, Oryza sativa. Global Change Biol. 5: 587-599.
Tiner R.W. 1988. Field Guide to Nontidal Wetland Identification. Maryland Department of Natural Resources and US Fish and Wildlife Service, Annapolis, MD, USA, Newton Corner, MA.
Updegraff K., Bridgham S.D., Pastor J., Weishampel P. and Harth C. 2001. Response of CO2 and CH4 emissions from peatlands to warming and water table manipulation. Ecol. Appl. 11: 311-326.
van Bodegon P., Stams F., Mollema L., Boeke S. and Leffelaar P. 2001. Methane oxidation and competition for oxygen in the rice rhizospere. Applied and Environ. Microbiol. 67: 3586-3597.
van der Nat F.J.W.A. and Middelburg J.J. 1998. Seasonal variation in methane oxidation by the rhizosphere of Phragmites australis and Scirpus lacustris. Aquat. Bot. 61: 95-110.
Vann C.D. 2000. Productivity and methane production in a future CO2-enriched atmosphere. MS thesis, George Mason University, Fairfax, USA.
Whiting G.J. and Chanton J.P. 1993. Primary production control of methane emission from wetlands. Nature 364: 794-795.
Yavitt J.B., Lang G.E. and Wieder R.K. 1987. Control of carbon mineralization to CH4 and CO2 in anaerobic sphagnum-derived peat from Big Run bog, West Virginia. Biogeochemistry 4: 141-157.
Ziska L.H., Moya T.B., Wassmann R., Namuco O.S., Lantin R.S., Aduna J.B. et al. 1998. Long-term growth at elevated carbon dioxide stimulates methane emission in tropical paddy rice. Global Change Biol. 4: 657-665.
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Vann, C.D., Patrick Megonigal, J. Elevated CO2 and water depth regulation of methane emissions: Comparison of woody and non-woody wetland plant species. Biogeochemistry 63, 117–134 (2003). https://doi.org/10.1023/A:1023397032331
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DOI: https://doi.org/10.1023/A:1023397032331