References

Biogeosciences

1726-4189

Copernicus Publications

Göttingen, Germany

10.5194/bg-10-2379-2013

The relative importance of decomposition and transport mechanisms in accounting for soil organic carbon profiles

Guenet

https://orcid.org/0000-0002-4311-8645

¹ ² Eglin

¹ Vasilyeva

https://orcid.org/0000-0002-1942-3738

³ Peylin

¹ Ciais

¹ Chenu

https://orcid.org/0000-0001-9054-0489

Laboratoire des Sciences du Climat et de l'Environnement, UMR8212, CEA-CNRS-UVSQ, 91191 Gif-sur-Yvette, France

Department of Biology, University of Antwerpen, Universiteitsplein 1, 2610, Wilrijk, Belgium

AgroParisTech, UPMC-CNRS-AgroParisTech UMR Bioemco7618, 78850 Thiverval-Grignon, France

10 04 2013

10 4 2379 2392

2013

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/10/2379/2013/bg-10-2379-2013.html

The full text article is available as a PDF file from https://bg.copernicus.org/articles/10/2379/2013/bg-10-2379-2013.pdf

Soil is the major terrestrial reservoir of carbon and a substantial part of this carbon is stored in deep layers, typically deeper than 50 cm below the surface. Several studies underlined the quantitative importance of this deep soil organic carbon (SOC) pool and models are needed to better understand this stock and its evolution under climate and land-uses changes. In this study, we tested and compared three simple theoretical models of vertical transport for SOC against SOC profiles measurements from a long-term bare fallow experiment carried out by the Central-Chernozem State Natural Biosphere Reserve in the Kursk Region of Russia. The transport schemes tested are diffusion, advection and both diffusion and advection. They are coupled to three different formulations of soil carbon decomposition kinetics. The first formulation is a first order kinetics widely used in global SOC decomposition models; the second one, so-called "priming" model, links SOC decomposition rate to the amount of fresh organic matter, representing the substrate interactions. The last one is also a first order kinetics, but SOC is split into two pools. Field data are from a set of three bare fallow plots where soil received no input during the past 20, 26 and 58 yr, respectively. Parameters of the models were optimised using a Bayesian method. The best results are obtained when SOC decomposition is assumed to be controlled by fresh organic matter (i.e., the priming model). In comparison to the first-order kinetic model, the priming model reduces the overestimation in the deep layers. We also observed that the transport scheme that improved the fit with the data depended on the soil carbon mineralisation formulation chosen. When soil carbon decomposition was modelled to depend on the fresh organic matter amount, the transport mechanism which improved best the fit to the SOC profile data was the model representing both advection and diffusion. Interestingly, the older the bare fallow is, the lesser the need for diffusion is, suggesting that stabilised carbon may not be transported within the profile by the same mechanisms than more labile carbon.

References 1

Afanasyeva, E. A.: Chernozemy sredne-russkoi vozvishennosti, Nauka, Moscow, 224 pp., 1966 (in Russian).

Baisden, W. T.: A multiisotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence, Global Biogeochem. Cy., 16, 1135, <a href="http://dx.doi.org/10.1029/2001GB001823">https://doi.org/10.1029/2001GB001823</a>, 2002.

Barré, P., Eglin, T., Christensen, B. T., Ciais, P., Houot, S., Kätterer, T., van Oort, F., Peylin, P., Poulton, P. R., Romanenkov, V., and Chenu, C.: Quantifying and isolating stable soil organic carbon using long-term bare fallow experiments, Biogeosciences, 7, 3839–3850, <a href="http://dx.doi.org/10.5194/bg-7-3839-2010">https://doi.org/10.5194/bg-7-3839-2010</a>, 2010.

Batjes, N. H.: Total carbon and nitrogen in the soils of the world, Eur. J. Soil Sci., 47, 151–163, 1996.

Braakhekke, M. C., Beer, C., Hoosbeek, M. R., Reichstein, M., Kruijt, B., Schrumpf, M., and Kabat, P.: SOMPROF: A vertically explicit soil organic matter model, Ecol. Model., 222, 1712–1730, 2011.

Bruun, S., Christensen, B. T., Thomsen, I. K., Jensen, E. S., and Jensen, L. S.: Modeling vertical movement of organic matter in a soil incubated for 41 years with <sup>14</sup>C labeled straw, Soil Biol. Biochem., 39, 368–371, 2007.

Coleman, K., Jenkinson, D. S., Crocker, G. J., Grace, P. R., Klir, J., Körschens, M., Poulton, P. R., and Richter, D. D.: Simulating trends in soil organic carbon in long-term experiments using RothC-26.3., Geoderma, 81, 29–44, 1997.

Decaëns, T.: Macroecological patterns in soil communities, Glob. Ecol. Biogeogr., 19, 287–302, 2010.

Dörr, H. and Münnich, K.: Downward movement of soil organic matter and its influence on trace element transport, Radiocarbon, 31, 655–663, 1989.

Elzein, A. and Balesdent, J.: Mechanistic Simulation of Vertical- Distribution of Carbon Concentrations and Residence Times in Soils, Soil Sci. Soc. Am. J., 59, 1328–1335, 1995.

Feng, X., Peterson, J. C., Quideau, S. A., Virginia, R. A., Graham, R. C., Sonder, L. J., and Chadwick, O. A.: Distribution, accumulation, and fluxes of soil carbon in four monoculture lysimeters at San Dimas Experimental Forest, California, Geochim. Cosmochim. Ac., 63, 1319–1333, 1999.

Fontaine, S. and Barot, S.: Size and functional diversity of microbe populations control plant persistence and long-term soil carbon accumulation, Ecol. Lett., 8, 1075–1087, 2005.

Fontaine, S., Barot, S., Barré, P., Bdioui, N., Mary, B., and Rumpel, C.: Stability of organic carbon in deep soil layers controlled by fresh carbon supply, Nature, 450, 277–280, 2007.

Friedlingstein, P., Cox, P., Betts, R., Bopp, L., Von Bloh, W., Brovkin, V., Cadule, P., Doney, S., Eby, M., Fung, I., Bala, G., John, J., Jones, C., Joos, F., Kato, T., Kawamiya, M., Knorr, W., Lindsay, K., Matthews, H. D., Raddatz, T., Rayner, P., Reick, C., Roeckner, E., Schnitzler, K. G., Schnur, R., Strassmann, K., Weaver, A. J., Yoshikawa, C., and Zeng, N.: Climate-carbon cycle feedback analysis: Results from the C4MIP model intercomparison, J. Climate 19, 3337–3353, 2006.

Gauch Jr., H. G., Hwang, J. T., and Fick, G. W.: Model Evaluation by Comparison of Model-Based Predictions and Measured Values, Agron. J., 95, 1442–1446, 2003.

Guenet, B., Lenhart, K., Leloup, J., Giusti-Miller, S., Pouteau, V., Mora, P., Nunan, N., and Abbadie, L.: The impact of long-term CO<sub>2</sub> enrichment and moisture levels on soil microbial community structure and enzyme activities, Geoderma, 170, 331–336, 2011.

Hirsch, P. R., Gilliam, L. M., Sohi, S. P., Williams, J. K., Clark, I. M., and Murray, P. J.: Starving the soil of plant input for 50 years reduces abundance but not diversity of soil bacterial communities, Soil Biol. Biochem., 41, 2021–2024, 2009.

Jenkinson, D. S. and Coleman, K.: The turnover of organic carbon in subsoils. Part 2. Modelling carbon turnover, Eur. J. Soil Sci., 59, 400–413, 2008.

Jobbagy, E. G. and Jackson, R. B.: The vertical distribution of soil organic carbon and its relation to climate and vegetation, Ecol. Appl., 10, 423–436, 2000.

Kobayashi, K. S. and Salam, M. U.: Comparing simulated and measured values using mean squared deviation and its components. Agron. J., 92, 345–352, 2000.

Lueken H., Hutcheon, W. L., and Paul, E. A.: The influence of nitrogen on the decomposition of crop residues in soil, Can. J. of Soil Sci., 42, 276–288, 1962.

Manzoni, S. and Porporato, A.: Soil carbon and nitrogen mineralisation: Theory and models across scales, Soil Biol. Biochem., 41, 1355–1379, 2009.

MEA: Millennium Ecosystem Assessment-Nutrient Cycling, World Resource Institute, Washington DC, 2005.

Mikhailova, E. A., Vassenev, R. B., Schwager, I. I., and Post, S. J.: Cultivation effects on soil carbon and nitrogen contents at depth in the Russian Chernozem, Soil Sci. Soc. Am. J., 64, 738–745, 2000

O'Brien, B. J. and Stout, J. D.: Movement and turnover of soil organic matter as indicated by carbon isotope measurements, Soil Biol. Biochem., 10, 309–317, 1977.

Parton, W. J., Stewart, J. W. B., and Cole, C. V.: Dynamics of C, N, P and S in grassland soils – a model, Biogeochemistry, 5, 109–131, 1988.

Pettersson, M. and Bååth, E.: Temperature-dependent changes in the soil bacterial community in limed and unlimed soil, FEMS Microbiol. Ecol., 45, 13–21, 2003.

R Development Core Team: A language and environment for statistical computing, R Foundation for Statistical Computing, Vienna, Austria, ISBN 3-900051-07-0, <a href="http://www.R-project.org.">http://www.R-project.org.</a>, 2010.

Rumpel, C. and Kögel-Knabner, I.: Deep soil organic matter – a key but poorly understood component of terrestrial C cycle, Plant Soil, 338, 143–158, 2010.

Salomé, C., Nunan, N., Pouteau, V., Lerch, T. Z., and Chenu, C.: Carbon dynamics in topsoil and in subsoil may be controlled by different regulatory mechanisms, Glob. Change Biol., 16, 416–426, 2010.

Sanaullah, M., Chabbi, A., Leifeld, J., Bardoux, G., Billou, D., and Rumpel, C.: Decomposition and stabilization of root litter in top-and subsoil horizons: what is the difference?, Plant Soil, 338, 127–141, 2010.

Santaren, D., Peylin, P., Viovy, N., and Ciais, P.: Optimizing a process-based ecosystem model with eddy-covariance flux measurements: A pine forest in southern France, Global Biogeochem. Cy., 21, GB2013, <a href="http://dx.doi.org/10.1029/2006GB002834">https://doi.org/10.1029/2006GB002834</a>, 2007.

Schimel, D. S.: Terrestrial ecosystems and the carbon cycle, Glob. Change Biol., 1, 77–91, 1995.

Schlesinger, H. W.: Evidence from chronosequence studies for a low carbon-storage potential of soils, Nature, 348, 232–234, 1990.

Soetaert, K., Petzoldt, T., and Setzer, R. W.: Solving Differential Equations in R: Package deSolve, J. Stat. Softw., 33, 1–25, 2010.

Sparling, G. S., Cheschire, M. V., and Mundie, C. M.: Effect of barley plants on the decomposition of 14C-labelled soil organic matter, J. Soil Sci., 33, 89–100, 1982.

Sugden, A., Stone, R., and Ash, C.: Ecology in the underworld – Introduction, Science, 304, 1613–1613, 2004.

Tarantola, A.: Inverse Problem Theory: Methods of Data Fitting and Model Parameter Estimation, Elsevier Science Ltd., 630 pp., 1987.

Tarnocai, C., Canadell, J. G., Schuur, E. A. G., Kuhry, P., Mazhitova, G., and Zimov, S.: Soil organic carbon pools in the northern circum-polar permafrost region, Global Biogeochem. Cy., 23, GB2023, <a href="http://dx.doi.org/10.1029/2008GB003327">https://doi.org/10.1029/2008GB003327</a>, 2009.

Vasilyeva, N. A., Chenu, C., Tyugai, Z. N., and Milanovskiy, E. Y.: Century scale C metastability in full Chernozem profiles under changed organic matter input and tillage, in press, 2013.

Vinogradov, B. V.: Aerospace studies of protected natural areas in the USSR, in: Conservation, science and society, Nat. Resour. Res., XXI, Vol. 2, 435–448, UNESCO-UNEP, Paris, 1984.

Williams, M.: Response of microbial communities to water stress in irrigated and drought-prone tallgrass prairie soils, Soil Biol. Biochem., 39, 2750–2757, 2007.

Wu, J., Brookes, P. C., and Jenkinson, D. S.: Formation and destruction of microbial biomass during the decomposition of glucose and Ryegrass in Soil, Soil Biol. Biochem., 25, 1435–1441, 1993.

Wu, Y., Xiongsheng, Y., Haizhen, W., Na, D., and Jianming, X.: Does history matter? Temperature effects on soil microbial biomass and community structure based on the phospholipid fatty acid (PLFA) analysis, J. Soil Sediment, 10, 223–230, 2009.

Wutzler, T. and Reichstein, M.: Colimitation of decomposition by substrate and decomposers – a comparison of model formulations, Biogeosciences, 5, 749–759, <a href="http://dx.doi.org/10.5194/bg-5-749-2008">https://doi.org/10.5194/bg-5-749-2008</a>, 2008.

Wynn, J. G., Bird, M. I., and Wong, V. N. L.: Rayleigh distillation and the depth profile of 13C/12C ratios of soil organic carbon from soils of disparate texture in Iron Range National Park, Far North Queensland, Australia, Geochim. Cosmochim. Ac., 69, 1961–1973, 2005.

Zhu, C., Byrd, R. H., Lu, P., and Nocedal, J.: A limited memory algorithm for bound constrained optimisation, SIAM J. Sci. Stat. Comput., 16, 1190–1208, 1995.