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Distribution of Radiocarbon Ages in Soil Organic Matter by Thermal Fractionation

Published online by Cambridge University Press:  09 February 2016

Alain F Plante ,
Steven R Beaupré ,
Mark L Roberts  and
Troy Baisden
Alain F Plante*
Affiliation:
Dept. Earth and Environmental Science, University of Pennsylvania, 240 South 33rd Street, Hayden Hall, Philadelphia, Pennsylvania 19104-6316, USA
Steven R Beaupré
Affiliation:
NOSAMS, Woods Hole Oceanographic Institution, 266 Woods Hole Rd. MS#08, Woods Hole, Massachusetts 02543, USA
Mark L Roberts
Affiliation:
NOSAMS, Woods Hole Oceanographic Institution, 266 Woods Hole Rd. MS#08, Woods Hole, Massachusetts 02543, USA
Troy Baisden
Affiliation:
National Isotope Centre, GNS Science, PO Box 31-312, Lower Hutt, New Zealand
*
Corresponding author. Email: [email protected].
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Abstract

Radiocarbon analysis is an important tool in quantifying soil organic matter (SOM) dynamics within the terrestrial carbon cycle. However, there is increasing appreciation that representing SOM as a single, homogeneous pool with a single, mean 14C concentration is inadequate. We investigate whether the differing patterns in CO2 release during ramped-temperature oxidation reflect organic matter of different ages, and hypothesize that thermally labile SOM (combusting at low temperatures) consists of younger carbon than thermally resistant organic matter. Topsoil samples under contrasting land uses (native vegetation and long-term cultivation) were selected for 14C analysis before and after acid fumigation for the removal of carbonates. Results of bulk 14C analyses showed a significant shift in 14C age from 0.944 Fm under native vegetation to 0.790 Fm under cultivation. Four to 5 “fractions” associated with different CO2-evolution regions were identified by thermal analysis and analyzed for 14C via modifications to NOSAMS' established “programmed temperature pyrolysis system,” in which discrete CO2 fractions evolved during ramped-temperature oxidation were isotopically characterized by a microwave gas ion source (GIS) continuous-flow AMS (CFAMS) system. Results showed that while acid fumigation removed soil carbonates, the treatment also significantly altered the thermograms and inferred SOM composition. While direct attribution of 14C values to individual peaks is somewhat confounded by overlapping temperature ranges for oxidation of unique populations of carbon, in general, thermally stable fractions of SOM appear to be 14C-depleted compared to thermally reactive (low temperature) fractions regardless of pretreatment.

Type
Articles
Information
Radiocarbon , Volume 55 , Issue 2: Proceedings of the 21st International Radiocarbon Conference (Part 1 of 2) , 2013 , pp. 1077 - 1083
Copyright
Copyright © 2013 by the Arizona Board of Regents on behalf of the University of Arizona 

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References

Brodie, CR, Leng, MJ, Casfor, JSL, Kendrick, CP, Lloyd, JM, Yongqiang, Z, Bird, MI. 2011. Evidence for bias in C and N concentrations and δ13C composition of terrestrial and aquatic organic materials due to pre-analysis acid preparation methods. Chemical Geology 282(3–4):67–83.CrossRefGoogle Scholar
Campbell, CA, Lafond, GP, Moulin, AP, Townley-Smith, L, Zentner, RP. 1997. Crop production and soil organic matter in long-term crop rotations in the sub-humid Northern Great Plains of Canada. In: Paul, EA, Paustian, K, Elliott, ET, Cole, CV, editors. Soil Organic Matter in Temperate Agroecosystems. Boca Raton: CRC Press Inc. p 297–315.Google Scholar
Denef, K, Plante, AF, Six, J. 2009. Characterization of soil organic matter. In: Kutsch, W, Bahn, M, Heinemeyer, A, editors. Soil Carbon Dynamics: An Integrated Methodology. London: Cambridge University Press. p 91–126.Google Scholar
Dorodnikov, M, Fangmeier, A, Kuzyakov, Y. 2007. Thermal stability of soil organic matter pools and their δ13C values after C3-C4 vegetation change. Soil Biology & Biochemistry 39(5):1173–80.CrossRefGoogle Scholar
Fernández, JM, Peltre, C, Craine, JM, Plante, AF. 2012. Improved characterization of soil organic matter by thermal analysis using CO2/H2O evolved gas analysis. Environmental Science & Technology 46(16):8921–7.CrossRefGoogle ScholarPubMed
Harris, D, Horwath, WR, van Kessel, C. 2001. Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 isotopic analysis. Soil Science Society of America Journal 65(6):1853–6.Google Scholar
Komada, T, Anderson, MR, Dorfmeier, CL. 2008. Carbonate removal from coastal sediments for the determination of organic carbon and its isotopic signatures, δ13C and Δ14C: comparison of fumigation and direct acidification by hydrochloric acid. Limnology and Oceanography Methods 6:254–62.Google Scholar
Leinweber, P, Schulten, HR. 1999. Advances in analytical pyrolysis of soil organic matter. Journal of Analytical and Applied Pyrolysis 49(1–2):359–83.Google Scholar
Lopez-Capel, E, Abbott, GD, Thomas, KM, Manning, DAC. 2006. Coupling of thermal analysis with quadrupole mass spectrometry and isotope ratio mass spectrometry for simultaneous determination of evolved gases and their carbon isotopic composition. Journal of Analytical and Applied Pyrolysis 75(2):82–9.Google Scholar
Manning, DAC, Lopez-Capel, E, White, ML, Barker, S. 2008. Carbon isotope determination for separate components of heterogeneous materials using coupled thermogravimetric analysis/isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry 22(8):1187–95.Google Scholar
Murage, EW, Voroney, P, Beyaert, RP. 2007. Turnover of carbon in the free light fraction with and without charcoal as determined using the 13C natural abundance method. Geoderma 138(1–2):133–43.Google Scholar
Paul, EA, Morris, SJ, Conant, RT, Plante, AF. 2006. Does the acid hydrolysis-incubation method measure meaningful soil organic carbon pools? Soil Science Society of America Journal 70(3):1023–35.Google Scholar
Plante, AF, Fernández, JM, Haddix, ML, Steinweg, JM, Conant, RT. 2011. Biological, chemical and thermal indices of soil organic matter stability in four grassland soils. Soil Biology & Biochemistry 43(5):1051–8.Google Scholar
Ramnarine, R, Voroney, RP, Wagner-Riddle, C, Dunfield, KE. 2011. Carbonate removal by acid fumigation for measuring the δ13C of soil organic carbon. Canadian Journal of Soil Science 91(2):247–50.CrossRefGoogle Scholar
Roberts, ML, von Reden, KF, McIntyre, CP, Burton, JR. 2011. Progress with a gas-accepting ion source for Accelerator Mass Spectrometry. Nuclear Instruments and Methods in Physics Research B 269(24):3192–5.CrossRefGoogle Scholar
Rosenheim, BE, Day, MB, Domack, E, Schrum, H, Benthien, A, Hayes, JM. 2008. Antarctic sediment chronology by programmed-temperature pyrolysis: Methodology and data treatment. Geochemistry, Geophysics, Geosystems 9(4):Q04005, doi:10.1029/2007GC001816.Google Scholar
Smith, JU, Smith, P, Monaghan, R, MacDonald, J. 2002. When is a measured soil organic matter fraction equivalent to a model pool? European Journal of Soil Science 53(3):405–16.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.Google Scholar
Trumbore, S. 2009. Radiocarbon and soil carbon dynamics. Annual Review of Earth and Planetary Sciences 37(1):47–66.Google Scholar
Trumbore, SE, Zheng, SH. 1996. Comparison of fractionation methods for soil organic matter 14C analysis. Radiocarbon 38(2):219–29.CrossRefGoogle Scholar
von Lützow, M, Kögel-Knabner, I, Ekschmitt, K, Flessa, H, Guggenberger, G, Matzner, E, Marschner, B. 2007. SOM fractionation methods: relevance to functional pools and to stabilization mechanisms. Soil Biology & Biochemistry 39(9):2183–207.Google Scholar
Wang, S-L, Burr, GS, Chen, Y-G, Lin, Y, Wu, T-S. 2013. Low-temperature and temperature stepped-combustion of terrace sediments from Nanfu, Taiwan. Radiocarbon, these proceedings, doi: 10.2458/azu_js_rc.55.16285.Google Scholar