References

Biogeosciences

1726-4189

Copernicus Publications

Göttingen, Germany

10.5194/bg-11-2325-2014

Methane and nitrous oxide fluxes across an elevation gradient in the tropical Peruvian Andes

Teh

Y. A.

https://orcid.org/0000-0001-7976-6794

¹ ⁶ Diem

¹ Jones

https://orcid.org/0000-0002-8686-1447

² Huaraca Quispe

L. P.

³ Baggs

⁴ Morley

⁴ Richards

⁴ Smith

https://orcid.org/0000-0002-3784-1124

⁴ Meir

² ⁵

Department of Earth and Environmental Sciences, University of St Andrews, Scotland, UK

School of Geosciences, University of Edinburgh, Scotland, UK

Universidad Nacional de San Antonio Abad del Cusco, Peru

Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK

Research School of Biology, Australian National University, Canberra, Australia

now at: Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, Scotland, UK

25 04 2014

11 8 2325 2339

2014

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

This article is available from https://bg.copernicus.org/articles/11/2325/2014/bg-11-2325-2014.html

The full text article is available as a PDF file from https://bg.copernicus.org/articles/11/2325/2014/bg-11-2325-2014.pdf

Remote sensing and inverse modelling studies indicate that the tropics emit more CH4 and N2O than predicted by bottom-up emissions inventories, suggesting that terrestrial sources are stronger or more numerous than previously thought. Tropical uplands are a potentially large and important source of CH4 and N2O often overlooked by past empirical and modelling studies. To address this knowledge gap, we investigated spatial, temporal and environmental trends in soil CH4 and N2O fluxes across a long elevation gradient (600–3700 m a.s.l.) in the Kosñipata Valley, in the southern Peruvian Andes, that experiences seasonal fluctuations in rainfall. The aim of this work was to produce preliminary estimates of soil CH4 and N2O fluxes from representative habitats within this region, and to identify the proximate controls on soil CH4 and N2O dynamics. Area-weighted flux calculations indicated that ecosystems across this altitudinal gradient were both atmospheric sources and sinks of CH4 on an annual basis. Montane grasslands (3200–3700 m a.s.l.) were strong atmospheric sources, emitting 56.94 ± 7.81 kg CH4-C ha−1 yr−1. Upper montane forest (2200–3200 m a.s.l.) and lower montane forest (1200–2200 m a.s.l.) were net atmospheric sinks (−2.99 ± 0.29 and −2.34 ± 0.29 kg CH4-C ha−1 yr−1, respectively); while premontane forests (600–1200 m a.s.l.) fluctuated between source or sink depending on the season (wet season: 1.86 ± 1.50 kg CH4-C ha−1 yr−1; dry season: −1.17 ± 0.40 kg CH4-C ha−1 yr−1). Analysis of spatial, temporal and environmental trends in soil CH4 flux across the study site suggest that soil redox was a dominant control on net soil CH4 flux. Soil CH4 emissions were greatest from habitats, landforms and during times of year when soils were suboxic, and soil CH4 efflux was inversely correlated with soil O2 concentration (Spearman's ρ = −0.45, P < 0.0001) and positively correlated with water-filled pore space (Spearman's ρ = 0.63, P <0.0001). Ecosystems across the region were net atmospheric N2O sources. Soil N2O fluxes declined with increasing elevation; area-weighted flux calculations indicated that N2O emissions from premontane forest, lower montane forest, upper montane forest and montane grasslands averaged 2.23 ± 1.31, 1.68 ± 0.44, 0.44 ± 0.47 and 0.15 ± 1.10 kg N2O-N ha−1 yr−1, respectively. Soil N2O fluxes from premontane and lower montane forests exceeded prior model predictions for the region. Comprehensive investigation of field and laboratory data collected in this study suggest that soil N2O fluxes from this region were primarily driven by denitrification; that nitrate (NO3−) availability was the principal constraint on soil N2O fluxes; and that soil moisture and water-filled porosity played a secondary role in modulating N2O emissions. Any current and future changes in N management or anthropogenic N deposition may cause shifts in net soil N2O fluxes from these tropical montane ecosystems, further enhancing this emission source.

References 1

Baggs, E. M., Richter, M., Cadisch, G., and Hartwig, U. A.: Denitrification in grass swards is increased under elevated atmospheric CO2, Soil. Biol. Biochem., 35, 729–732, 2003.

Bateman, E. J. and Baggs, E. M.: Contributions of nitrification and denitrification to N2O emissions from soils at different water-filled pore space, Biol. Fertil. Soils, 41, 379–388, 2005.

Belyea, L. R. and Baird, A. J.: Beyond the limits to peat bog growth: Cross-scale feedback in peatland development, Ecol. Monogr., 76, 299–322, 2006.

Bergamaschi, P., Frankenberg, C., Meirink, J. F., Krol, M., Dentener, F., Wagner, T., Platt, U., Kaplan, J. O., Korner, S., Heimann, M., Dlugokencky, E. J., and Goede, A.: Satellite chartography of atmospheric methane from SCIAMACHY onboard ENVISAT: 2. Evaluation based on inverse model simulations, J. Geophys. Res.-Atmos., 112, 1–26, 2007.

Bergamaschi, P., Frankenberg, C., Meirink, J. F., Krol, M., Villani, M. G., Houweling, S., Dentener, F., Dlugokencky, E. J., Miller, J. B., Gatti, L. V., Engel, A., and Levin, I.: Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite retrievals, J. Geophys. Res.-Atmos., 114, 1–28, 2009.

Blackmer, A. M. and Bremner, J. M.: Inhibitory effect of nitrate on reduction of N2O to N2 by soil microorganisms, Soil Biol. Biochem., 10, 187–191, 1978.

Breuer, L., Papen, H., and Butterbach-Bahl, K.: N2O emission from tropical forest soils of Australia, J. Geophys. Res.-Atmos., 105, 26353–26367, 2000.

Clark, M., Jarvis, S., and Maltby, E.: An improved technique for measuring concentration of soil gases at depth in situ, Commun. Soil Sci. Plant Anal., 32, 369–377, 2001.

Covey, K. R., Wood, S. A., Warren, R. J., Lee, X., and Bradford, M. A.: Elevated methane concentrations in trees of an upland forest, Geophys. Res. Lett., 39, L15705, 15701–15706, 2012.

Davidson, E. A.: Fluxes of nitrous oxide and nitric oxide from terrestrial ecosystems, in: Microbial production and consumption of greenhouse gases: methane, nitrogen oxides, and halomethanes, edited by: Rogers, J. E., and Whitman, W. B., American Society for Microbiology, Washington DC, 219–236, 1991.

Davidson, E. A., Matson, P. A., Vitousek, P. M., Riley, R., Dunkin, K., Garciamendez, G., and Maass, J. M.: Processes regulating soil emissions of NO and N2O in a seasonally dry tropical forest, Ecology, 74, 130–139, 1993.

Davidson, E. A. and Verchot, L. V.: Testing the Hole-in-the-Pipe Model of nitric and nitrous oxide emissions from soils using the TRAGNET Database, Global Biogeochem. Cy., 14, 1035–1043, 2000.

Davidson, E. A., Verchot, L. V., Cattanio, J. H., Ackerman, I. L., and Carvalho, J. E. M.: Effects of soil water content on soil respiration in forests and cattle pastures of eastern Amazonia, Biogeochemistry, 48, 53–69, 2000.

Davidson, E. A., Nepstad, D. C., Ishida, F. Y., and Brando, P. M.: Effects of an experimental drought and recovery on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest, Glob. Change Biol., 14, 2582–2590, 2008.

Dutaur, L. and Verchot, L. V.: A global inventory of the soil CH4 sink, Global Biogeochem. Cy., 21, 1–9, 2007.

Eva, H. D., Belward, A. S., De Miranda, E. E., Di Bella, C. M., Gond, V., Huber, O., Jones, S., Sgrenzaroli, M., and Fritz, S.: A land cover map of South America, Glob. Change Biol., 10, 731–744, 2004.

Feeley, K. J. and Silman, M. R.: Land-use and climate change effects on population size and extinction risk of Andean plants, Glob. Change Biol., 16, 3215-3222, 10.1111/j.1365-2486.2010.02197.x, 2010.

Firestone, M. K. and Davidson, E. A.: Microbiological basis of NO and N2O production and consumption in soil, Exchange of Trace Gases between Terrestrial Ecosystems and the Atmosphere, edited by: Andreae, M. O. and Schimel, D. S., John Wiley & Sons, New York, 7–21, 1989.

Firestone, M. K., Firestone, R. B., and Tiedge, J. M.: Nitrous oxide from soil denitrification: Factors controlling its biological production, Science, 208, 749–751, 1980.

Fisher, J. B., Malhi, Y., Torres, I. C., Metcalfe, D. B., van de Weg, M. J., Meir, P., Silva-Espejo, J. E., and Huasco, W. H.: Nutrient limitation in rainforests and cloud forests along a 3000-m elevation gradient in the Peruvian Andes, Oecologia, 172, 889–902, 2013.

Fletcher, S. E. M., Tans, P. P., Bruhwiler, L. M., Miller, J. B., and Heimann, M.: CH4 sources estimated from atmospheric observations of CH4 and its C-13/C-12 isotopic ratios: 1. Inverse modeling of source processes, Global Biogeochem. Cy., 18, 1–17, 2004a.

Fletcher, S. E. M., Tans, P. P., Bruhwiler, L. M., Miller, J. B., and Heimann, M.: CH4 sources estimated from atmospheric observations of CH4 and its C-13/C-12 isotopic ratios: 2. Inverse modeling of CH4 fluxes from geographical regions, Global Biogeochem. Cy., 18, 1–15, 2004b.

Frankenberg, C., Meirink, J. F., van Weele, M., Platt, U., and Wagner, T.: Assessing methane emissions from global space-borne observations, Science, 308, 1010–1014, 2005.

Frankenberg, C., Bergamaschi, P., Butz, A., Houweling, S., Meirink, J. F., Notholt, J., Petersen, A. K., Schrijver, H., Warneke, T., and Aben, I.: Tropical methane emissions: A revised view from SCIAMACHY onboard ENVISAT, Geophys. Res. Lett., 35, 1–5, 2008.

Fung, I., John, J., Lerner, J., Matthews, E., Prather, M., Steele, L., and Fraser, P.: Three-Dimensional Model Synthesis of the Global Methane Cycle, J. Geophys. Res.-Atmos., 96, 13033–13065, 1991.

Gauci, V., Gowing, D. J. G., Hornibrook, E. R. C., Davis, J. M., and Dise, N. B.: Woody stem methane emission in mature wetland alder trees, Atmos. Environ., 44, 2157–2160, 2010.

Gibbon, A., Silman, M. R., Malhi, Y., Fisher, J. B., Meir, P., Zimmermann, M., Dargie, G. C., Farfan, W. R., and Garcia, K. C.: Ecosystem Carbon Storage Across the Grassland-Forest Transition in the High Andes of Manu National Park, Peru, Ecosystems, 13, 1097–1111, 2010.

Girardin, C. A. J., Malhi, Y., AragÃO, L. E. O. C., Mamani, M., Huaraca Huasco, W., Durand, L., Feeley, K. J., Rapp, J., Silva-Espejo, J. E., Silman, M., Salinas, N., and Whittaker, R. J.: Net primary productivity allocation and cycling of carbon along a tropical forest elevational transect in the Peruvian Andes, Glob. Change Biol., 16, 3176–3192, 2010.

Groffman, P. M., Butterbach-Bahl, K., Fulweiler, R. W., Gold, A. J., Morse, J. L., Stander, E. K., Tague, C., Tonitto, C., and Vidon, P.: Challenges to incorporating spatially and temporally explicit phenomena (hotspots and hot moments) in denitrification models, Biogeochemistry, 93, 49–77, 2009.

Hall, S. J. and Matson, P. A.: Nitrogen oxide emissions after nitrogen additions in tropical forests, Nature, 400, 152–155, 1999.

Hirsch, A. I., Michalak, A. M., Bruhwiler, L. M., Peters, W., Dlugokencky, E. J., and Tans, P. P.: Inverse modeling estimates of the global nitrous oxide surface flux from 1998-2001, Global Biogeochem. Cy., 20, 1–17, 2006.

Huang, J., Golombek, A., Prinn, R., Weiss, R., Fraser, P., Simmonds, P., Dlugokencky, E. J., Hall, B., Elkins, J., Steele, P., Langenfelds, R., Krummel, P., Dutton, G., and Porter, L.: Estimation of regional emissions of nitrous oxide from 1997 to 2005 using multinetwork measurements, a chemical transport model, and an inverse method, J. Geophys. Res.-Atmos., 113, 1-19, 2008.

Kammann, C., Grunhage, L., and Jager, H. J.: A new sampling technique to monitor concentrations of CH4, N2O and CO2 in air at well-defined depths in soils with varied water potential, European J. Soil Sci., 52, 297–303, 2001.

Keller, M. and Reiners, W. A.: Soil atmosphere exchange of nitrous oxide, nitric oxide, and methane under secondary succession of pasture to forest in the Atlantic lowlands of Costa Rica, Global Biogeochem. Cy., 8, 399–409, 1994.

Keller, M., Kaplan, W. A., and Wofsy, S. C.: Emissions of N2O, CH4 and CO2 from tropical forest soils, J. Geophys. Res.-Atmos., 91, 1791–1802, 1986.

Keller, M., Veldkamp, E., Weltz, A., and Reiners, W.: Effect of pasture age on soil trace-gas emissions from a deforested area of Costa Rica, Nature, 365, 244–246, 1993.

Keppler, F., Hamilton, J. T. G., Brass, M., and Rockmann, T.: Methane emissions from terrestrial plants under aerobic conditions, Nature, 439, 187–191, 2006.

Kort, E. A., Patra, P. K., Ishijima, K., Daube, B. C., Jimenez, R., Elkins, J., Hurst, D., Moore, F. L., Sweeney, C., and Wofsy, S. C.: Tropospheric distribution and variability of N2O: Evidence for strong tropical emissions, Geophys. Res. Lett., 38, 1–5, 2011.

Livingston, G. and Hutchinson, G.: Chapter 2: Enclosure-based measurement of trace gas exchange: applications and sources of error, in: Biogenic Trace Gases: Measuring Emissions from Soil and Water, edited by: Matson, P., Harriss, RC, Blackwell Science Ltd, Cambridge, MA, USA, 14–51, 1995.

Malhi, Y., Silman, M., Salinas, N., Bush, M., Meir, P., and Saatchi, S.: Introduction: Elevation gradients in the tropics: laboratories for ecosystem ecology and global change research, Glob. Change Biol., 16, 3171–3175, 2010.

Martinson, G. O., Werner, F. A., Scherber, C., Conrad, R., Corre, M. D., Flessa, H., Wolf, K., Klose, M., Gradstein, S. R., and Veldkamp, E.: Methane emissions from tank bromeliads in neotropical forests, Nature Geosci., 3, 766–769, 2010.

Melack, J. M., Hess, L. L., Gastil, M., Forsberg, B. R., Hamilton, S. K., Lima, I. B. T., and Novo, E.: Regionalization of methane emissions in the Amazon Basin with microwave remote sensing, Glob. Change Biol., 10, 530–544, 2004.

Nevison, C. D., Mahowald, N. M., Weiss, R. F., and Prinn, R. G.: Interannual and seasonal variability in atmospheric N2O, Global Biogeochem. Cy., 21, 1–13, 2007.

Nevison, C. D., Dlugokencky, E., Dutton, G., Elkins, J. W., Fraser, P., Hall, B., Krummel, P. B., Langenfelds, R. L., O'Doherty, S., Prinn, R. G., Steele, L. P., and Weiss, R. F.: Exploring causes of interannual variability in the seasonal cycles of tropospheric nitrous oxide, Atmos. Chem. Phys., 11, 3713–3730, <a href="http://dx.doi.org/10.5194/acp-11-3713-2011">https://doi.org/10.5194/acp-11-3713-2011</a>, 2011.

Pangala, S. R., Moore, S., Hornibrook, E. R. C., and Gauci, V.: Trees are major conduits for methane egress from tropical forested wetlands, New Phytol., 197, 524–531, 2013.

Pedersen, A. R., Petersen, S. O., and Schelde, K.: A comprehensive approach to soil-atmosphere trace-gas flux estimation with static chambers, European J. Soil Sci., 61, 888–902, 2010.

Potter, C. S., Davidson, E. A., and Verchot, L. V.: Estimation of global biogeochemical controls and seasonality in soil methane consumption, Chemosphere, 32, 2219–2246, 1996.

Pumpanen, J., Kolari, P., Ilvesniemi, H., Minkkinen, K., Vesala, T., Niinisto, S., Lohila, A., Larmola, T., Morero, M., Pihlatie, M., Janssens, I., Yuste, J. C., Grunzweig, J. M., Reth, S., Subke, J. A., Savage, K., Kutsch, W., Ostreng, G., Ziegler, W., Anthoni, P., Lindroth, A., and Hari, P.: Comparison of different chamber techniques for measuring soil CO2 efflux, Agr. Forest Meteorol., 123, 159–176, 2004.

Purbopuspito, J., Veldkamp, E., Brumme, R., and Murdiyarso, D.: Trace gas fluxes and nitrogen cycling along an elevation sequence of tropical montane forests in Central Sulawesi, Indonesia, Global Biogeochem. Cy., 20, 1–11, 2006.

R Core Team: A language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria, <a href="http://www.R-project.org/">http://www.R-project.org/</a>, 2012.

Ridgwell, A. J., Marshall, S. J., and Gregson, K.: Consumption of atmospheric methane by soils: A process-based model, Global Biogeochem. Cy., 13, 59–70, 1999.

Silver, W., Lugo, A., and Keller, M.: Soil oxygen availability and biogeochemistry along rainfall and topographic gradients in upland wet tropical forest soils, Biogeochemistry, 44, 301–328, 1999.

Silver, W. L., Herman, D. J., and Firestone, M. K. S.: Dissimilatory Nitrate Reduction to Ammonium in Upland Tropical Forest Soils, Ecology, 82, 2410–2416, 2001.

Spahni, R., Wania, R., Neef, L., van Weele, M., Pison, I., Bousquet, P., Frankenberg, C., Foster, P. N., Joos, F., Prentice, I. C., and van Velthoven, P.: Constraining global methane emissions and uptake by ecosystems, Biogeosciences, 8, 1643–1665, <a href="http://dx.doi.org/10.5194/bg-8-1643-2011">https://doi.org/10.5194/bg-8-1643-2011</a>, 2011.

Teh, Y. A., Silver, W., and Conrad, M.: Oxygen effects on methane production and oxidation in humid tropical forest soils, Glob. Change Biol., 11, 1283–1297, 2005.

Teh, Y. A., Silver, W. L., Sonnentag, O., Detto, M., Kelly, M., and Baldocchi, D. D.: Large greenhouse gas emissions from a temperate peatland pasture, Ecosystems, 14, 311–325, <a href="http://dx.doi.org/10.1007/s10021-011-9411-4">https://doi.org/10.1007/s10021-011-9411-4</a>, 2011.

Templer, P. H., Lovett, G. M., Weathers, K. C., Findlay, S. E., and Dawson, T. E.: Influence of tree species on forest nitrogen retention in the Catskill Mountains, New York, USA, Ecosystems, 8, 1–16, 2005.

Terazawa, K., Ishizuka, S., Sakatac, T., Yamada, K., and Takahashi, M.: Methane emissions from stems of Fraxinus mandshurica var. japonica trees in a floodplain forest, Soil Biol. Biochem., 39, 2689–2692, 2007.

van de Weg, M. J., Meir, P., Grace, J., and Atkin, O. K.: Altitudinal variation in leaf mass per unit area, leaf tissue density and foliar nitrogen and phosphorus content along an Amazon-Andes gradient in Peru, Plant Ecol. Diversity, 2, 243–U247, 2009.

Varner, R. K., Keller, M., Robertson, J. R., Dias, J. D., Silva, H., Crill, P. M., McGroddy, M., and Silver, W. L.: Experimentally induced root mortality increased nitrous oxide emission from tropical forest soils, Geophys. Res. Lett., 30, 1–4, 2003.

Veldkamp, E., Purbopuspito, J., Corre, M. D., Brumme, R., and Murdiyarso, D.: Land use change effects on trace gas fluxes in the forest margins of Central Sulawesi, Indonesia, J. Geophys. Res.-Biogeosci., 113, 1–11, 2008.

Verchot, L. V., Davidson, E. A., Cattanio, J. H., and Ackerman, I. L.: Land-use change and biogeochemical controls of methane fluxes in soils of eastern Amazonia, Ecosystems, 3, 41–56, 2000.

von Fischer, J. and Hedin, L.: Separating methane production and consumption with a field-based isotope dilution technique, Global Biogeochem. Cy., 16, 1–13, 2002.

von Fischer, J. C. and Hedin, L. O.: Controls on soil methane fluxes: Tests of biophysical mechanisms using stable isotope tracers, Global Biogeochem. Cy., 21, GB2007, <a href="http://dx.doi.org/10.1029/2006gb002687">https://doi.org/10.1029/2006gb002687</a>, 2007.

von Fischer, J. C., Rhew, R. C., Ames, G. M., Fosdick, B. K., and von Fischer, P. E.: Vegetation height and other controls of spatial variability in methane emissions from the Arctic coastal tundra at Barrow, Alaska, J. Geophys. Res.-Biogeosci., 115, 1–11, 2010.

Waddington, J. M. and Roulet, N. T.: Atmosphere-wetland carbon exchanges: Scale dependency of CO2 and CH4 exchange on the developmental topography of a peatland, Global Biogeochem. Cy., 10, 233–245, 1996.

Wania, R., Jolleys, M., and Buytaert, W.: Methane emissons from the Andean paramo – a previously neglected methane source? iLEAPS Newsletter, 7, 58–59, 2007.

Weier, K. L., Doran, J. W., Power, J. F., and Walters, D. T.: Denitrification and the denitrogen nitrous oxide ratio as affected by soil water, available carbon, and nitrate, Soil Sci. Soc. Am. J., 57, 66–72, 1993.

Werner, C., Butterbach-Bahl, K., Haas, E., Hickler, T., and Kiese, R.: A global inventory of N2O emissions from tropical rainforest soils using a detailed biogeochemical model, Global Biogeochem. Cy., 21, 1–18, 2007.

Wolf, K., Veldkamp, E., Homeier, J., and Martinson, G. O.: Nitrogen availability links forest productivity, soil nitrous oxide and nitric oxide fluxes of a tropical montane forest in southern Ecuador, Global Biogeochem. Cy., 25, 1–12, 2011.

Wolf, K., Flessa, H., and Veldkamp, E.: Atmospheric methane uptake by tropical montane forest soils and the contribution of organic layers, Biogeochemistry, 111, 469–483, 2012.

Yang, W. H., Teh, Y. A., and Silver, W. L.: A test of a field-based 15N–nitrous oxide pool dilution technique to measure gross N2O production in soil, Glob. Change Biol., 17, 3577–3588, 2011.

Zimmermann, M., Meir, P., Bird, M. I., Malhi, Y., and Ccahuana, A. J. Q.: Climate dependence of heterotrophic soil respiration from a soil-translocation experiment along a 3000 m tropical forest altitudinal gradient, Europ. J. Soil Sci., 60, 895–906, 2009.

Zimmermann, M., Meir, P., Bird, M. I., Malhi, Y., and Ccahuana, A. J. Q.: Temporal variation and climate dependence of soil respiration and its components along a 3000 m altitudinal tropical forest gradient, Global Biogeochem. Cy., 24, 4011–4013, 2010a.

Zimmermann, M., Meir, P., Silman, M. R., Fedders, A., Gibbon, A., Malhi, Y., Urrego, D. H., Bush, M. B., Feeley, K. J., Garcia, K. C., Dargie, G. C., Farfan, W. R., Goetz, B. P., Johnson, W. T., Kline, K. M., Modi, A. T., Rurau, N. M. Q., Staudt, B. T., and Zamora, F.: No Differences in Soil Carbon Stocks Across the Tree Line in the Peruvian Andes, Ecosystems, 13, 62–74, 2010b.