References

Biogeosciences

1726-4189

Copernicus Publications

Göttingen, Germany

10.5194/bg-4-385-2007

Long-term steady state 13C labelling to investigate soil carbon turnover in grasslands

Klumpp

¹ Soussana

J. F.

¹ Falcimagne

INRA, UR874 Grassland Ecosystem Research, Clermont-Ferrand, France

26 06 2007

4 3 385 394

2007

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/

This article is available from https://bg.copernicus.org/articles/4/385/2007/bg-4-385-2007.html

The full text article is available as a PDF file from https://bg.copernicus.org/articles/4/385/2007/bg-4-385-2007.pdf

We have set up a facility allowing steady state 13CO2 labeling of short stature vegetation (12 m2) for several years. 13C labelling is obtained by scrubbing the CO2 from outdoors air with a self-regenerating molecular sieve and by replacing it with 13C depleted (−34.7±0.03&permil;) fossil-fuel derived CO2 The facility, which comprises 16 replicate mesocosms, allows to trace the fate of photosynthetic carbon in plant-soil systems in natural light and at outdoors temperature. This method was applied to the study of soil organic carbon turnover in temperate grasslands. We tested the hypothesis that a low disturbance by grazing and cutting of the grassland increases the mean residence time of carbon in coarse (>0.2 mm) soil organic fractions. Grassland monoliths (0.5×0.5×0.4 m) were sampled from high and low disturbance treatments in a long-term (14 yrs) grazing experiment and were placed during two years in the mesocosms. During daytime, the canopy enclosure in each mesocosm was supplied in an open flow with air at mean CO2 concentration of 425 µmol mol−1 and δ13C of −21.5±0.27&permil;. Fully labelled mature grass leaves reached a δ13C of −40.8 (±0.93) and −42.2&permil; (±0.60) in the low and high disturbance treatments, respectively, indicating a mean 13C labelling intensity of 12.7&permil; compared to unlabelled control grass leaves. After two years, the delta 13C value of total soil organic matter above 0.2 mm was reduced in average by 7.8&permil; in the labelled monoliths compared to controls. The isotope mass balance technique was used to calculate for the top (0–10 cm) soil the fraction of 13C labelled carbon in the soil organic matter above 0.2 mm (i.e. roots, rhizomes and particulate organic matter). A first order exponential decay model fitted to the unlabelled C in this fraction shows an increase in mean residence time from 22 to 31 months at low compared to high disturbance. A slower decay of roots, rhizomes and particulate organic matter above 0.2 mm is therefore likely to contribute to the observed increased in soil carbon sequestration in grassland monoliths exposed to low disturbance.

References 1

Agren, G. I., Bosatta, E., and Balendent, J.: Isotope discrimination during decomposition of organic matter: A theoretical analysis, J. Soil Sci. Soc. Am. J., 60, 1121–1126, 1996.

Balesdent, J., Wagner, G. H., and Mariotti, A.: Soil organic matter turnover in long-term field experiment as revealed by carbon-13 natural abundance, Soil Sci. Soc. Am. J., 52, 118–124, 1988.

Brugnoli, E. and Farquhar, G. D.: Photosynthetic fractionation of carbon isotopes, in: Advances in photosythesis, vol. 9, Photosynthesis: Physiology and metabolism, edited by: Leegood, R. C., Sharkey, T. D., and von Caemmerer, S., Kluwer Academic Publisher, Dordrecht, The Netherlands, 2000.

Casella, E. E. and Soussana, J. F.: Long-term effects of CO2 and temperature increase on the carbon balance of a temperate grass sward, J. Exp. Bot., 48, 1309–1321, 1997.

Cebrian, J. and Duarte, C. M.: Plant growth-rate dependence of detrital carbon storage in ecosystems, Science, 268, 1606–1608, 1995.

Contant, R. T., Paustian, K., and Elliot, E. T.: Grassland management and can conversion into grassland, Effects on soil carbon, Ecol. App. 11, 343–355, 2001.

Conen, F., Leifeld, J., Seth, B., and Alewell, C.: Warming mineralisers young and old carbon equally, Biogeosciences, 3, 515–519, 2006.

Deléens, E., Pavlides, D., and Queiroz, O.: Application du traçage isotopique naturel par le C$^13 $ à la mesure du renouvellement de la matière foliaire chez les plantes en C3, Physiol. Veg., 21, 723–729, 1983.

Derner, J. D., Boutton, T. W., and Briske, D. D.: Grazing and ecosystem carbon storage in the North American Great Plains, Plant and Soil, 280, 77–90, 2006.

Dijkstra, F. A., Hobbie, S. E., Knops, J. M. H., and Reich, P. B.: Nitrogen deposition and plant species interact to influence soil carbon stabilization, Ecol. Letters, 7, 1192–1198, 2004.

Doak, B. W.: Some chemical changes in the nitrogenous constituents of urine when voided on pasture, J. Agric. Sci., 42, 162–171, 1952.

Evans, J. R., Sharkey, T. D., Berry, J. A., and Farquhar, G. D.: Carbon isotope discrimination measured concurrently with gas exchange to investigate CO2 diffusion in leaves of higher plants, Aust. J. Plant Physiol., 13, 281–292, 1986.

Farquhar, G. D., Ehleringer, J. R., and Hubick, K. T.: Carbon isotop discrimination and photosynthesis, Annu. Rev. Plant Physiol. Mol. Biol., 40, 403–437, 1989.

Gleixner, G., Danier, J., Werner, R. A., and Schmidt, L.:Correlation between the $^13$C content of primary and secondary products in different cell compartments and that in decomposing basidiomycetes, Plant Physiol., 102, 1287–1290, 1993.

Hobbie, E. A., Johnson, M. G., Rygiewicz, P. T., Tingey, D. T., and Olszyk, D. M.: Isotopic estimates of new carbon inputs into litter and soils in a four-year climate change experiment with Douglas-fir, Plant and Soil, 259, 331–343, 2004.

Hooper, D. U., Bignell, D. E., Brown, V. K., Brussaard, L., Dangerfield, D. M., and Wall, D. H.: Interactions between aboveground and belowground biodiversity in terrestrial ecosystems: Patterns, mechanisms, and feedbacks, Bioscience, 50, 1049–1061, 2000.

Hooper, D. U. and Vitousek, P. M.: Effects of plant composition and diversity on nutrient cycling, Ecol. Mono., 68, 121–149, 1998.

Jones, M. B. and Donelly, A.: Carbon sequestration in temperate grassland ecosystems and the influence of management, climate and elevated CO2, New Phytol., 164, 423–439, 2004.

Klumpp, K., Soussana, J. F., and Falcimagne, R.: Effects of past and current disturbance on carbon cycling in grassland mesocosms, Agric. Ecosyst. Environ., 121, 59–73, 2007.

Klumpp, K., Schäufele, R., Lötscher, M., Lattanzi, F. A., Feneis, W., and Schnyder, H.: C-isotope composition of CO2 respired by shoots and roots: fractionation during dark respiration?, Plant Cell Environm., 28, 241–250, 2005.

Loiseau, P. and Soussana, J. F.: Elevated [CO2], temperature increase and N supply effects on the accumulation of below-ground carbon in a temperate grassland ecosystem, Plant and Soil, 212, 123–134, 1999.

Louault, F., Pillar, V. D., Aufrere, J., Garnier, E., and Soussana, J. F.: Plant traits and function types in response to reduced disturbance in a semi-natural grassland, J. Veg. Sci., 16, 151–160, 2005.

Mellilo, J. M., Aber, J. D., Linkins, A. E., Ricca, A., Fry, B., and Nadelhoffer, K. J.: Carbon and nitrogen dynamics along the decay continuum: plant litter to soil organic matter, Plant and Soil, 115, 189–198, 1989.

O'Leary, M. H.: Carbon isotope fractionation in plants, Phytochemistry, 20, 553–567, 1981.

Ostle, N., Ineson, P., Benham, D., and Sleep, D.: Carbon assimilation and turnover in grassland vegetation using an in situ (CO$_2)$-C-13 pulse labelling system, Rap. Comm. Mass. Spec., 14, 1345–1350, 2000.

Ostle, N., Briones, M. J. I., Ineson, P., Cole, L., Staddon, P., and Sleep, D.: Isotopic detection of recent photosynthate carbon flow into grassland rhizosphere fauna, Soil Biol. Biochem., 39, 768–777, 2007.

Pataki, D. E., Bowling, D. R., and Ehleringer, J. R.: Seasonal eycle of carbon dioxid and its isotopic composition in an urban atmosphere: antropogenic and biogenic effects, J. Geophys. Res., 108, 1–8, 2004.

Personeni, E. and Loiseau, P.: Species strategy and N fluxes in grassland soil – A question of root litter quality or rhizosphere activity?, European J. Agr., 22, 217–229, 2005.

Personeni, E. and Loiseau, P.: How does the nature of living and dead roots affect the residence time of carbon in the root litter continuum?, Plant and Soil, 267, 129–141, 2004.

Picon-Cochard , C., Teyssonneyre, F., Besle, J. M., and Soussana, J. F.: Effects of elevated CO2 and cutting frequency on the productivity and herbage quality of a semi-natural grassland, Europ. J. Agro., 20, 363–377, 2004.

Rangel-Castro, J. I., Prosser, J. I., Ostle, N., Scrimgeour, C. M., Killham, K., and Meharg, A. A.: Flux and turnover of fixed carbon in soil microbial biomass of limed and unlimed plots of an upland grassland ecosystem, Environmental Microbiology, 7, 544–552, 2005.

Schapendonk, A. H. C. M., Dijkstra, P., Groenwold, J., Pot, C. S., and Van de Geijn, S. C.: Carbon balance and water use efficiency of frequently cut Lolium perenne L. Swards at elevated carbon dioxid, Global Change Biol., 3, 207–216, 1997.

Schlesinger, W. H.: Biochemistry: an Analysis of global Change, 2nd edn. Academic Press, San diego, CA, 1997.

Schnyder, H., Schäufele, R., Lötscher, M., and Gebbing, T.: Disentangling CO2 fluxes: direct measurements of mesocosm-scale natural abundance $^13$CO2/$^12$CO2 gas exchange, $^13$C discrimination, and labelling of CO2 exchange flux components in controlled environments, Plant, Cell and Environ., 26, 1863–1874, 2003.

Schnyder, H.: Long-term steady-state labelling of wheat plants by use of natural $^13$CO2/$^12$CO2 mixtures in an open, rapidly turned-over system, Planta, 187, 128–135, 1992.

Schweizer, M., Fear, J., and Cadisch, G.: Isotopic ($^13$C) fractionation during plant residue decomposition and its implication for soil organic matter studies, Rap. Comm. Mass. Spec., 13, 1284–1290, 1999.

Seeber, J., Scheu, S., and Meyer, E.: Effects of macro-decomposers on litter decomposition and soil properties in alpine pastureland: A mesocosm experiment, Appl. Soil Ecol., 34, 168–175, 2006.

Six, J., Guggenberger, D., Paustian, K., Haumaier, L., Elliot, E. T., and Zech, W.: Sources and compostion of soil organic matter fractions between and witin soil aggregates, Europ. J. Soil Sci., 52, 607–618, 2001.

Smith, J., Smith, P., Wattenbach, M., Zaehle, S., Hiederer, R., Jones, R. J. A., Montanarella, L., Rounsevell, M. D. A., Reginster, I., and Ewert, F.: Projected changes in mineral soil carbon of European croplands and grasslands, 1990–2080, Global Change Biol., 11, 2141–2152, 2005.

Stevenson, F. J.: Cycles of soil; carbon nitrogen, phosphorus, sulphur, micronutrients, John Wiley & Sons, Inc, New York, p. 23–33, 1986.

Tateno, M. and Chapin, F. S.: The logic of carbon and nitrogen interactions in terrestrial ecosystems, Am. Naturalist, 149, 723–744, 1997.

Trueman, R. J. and Gonzales-Meler, M. A.: Acceleration belowground C cycling in a managed agriforest ecosystem exposed to elevated carbon dioxide concentration, Glob. Chang. Biol., 11, 1258–1271, 2005.

Trumbore, S. E.: Carbon respired by terrestrial ecosystems – recent progress and challenges, Glob. Chang. Biol., 12, 141–153, 2000.

van Kessel, C., Boots, B., de Graaff, M.-A., Harris, D., Blum, H., and Six, J.: Total soil C and N sequestration in a grassland following 10 years of free air CO2 enrichment, Glob. Change Biol., 12, 2187–2199, 2006.

Verburg, P. S. J., Arnone, J. A., Obrist, D., Schorran, D. E., Evans, R. D., Leroux-Swarthout, D., Johnson, D. W., Luo, Y., and Coleman, J. S.: Net ecosystem carbon exchange in two experimental grassland ecosystems, Global Change Biol., 10, 498–508, 2004.