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Carbon and Oxygen Isotope Composition in Soil Carbon Dioxide and Free Oxygen within Deep Ultisols at the Calhoun CZO, South Carolina, USA

  • Alexander Cherkinsky (a1), Zachary Brecheisen (a2) and Daniel Richter (a2)


In order to evaluate effects of three land uses on isotopic compositions of CO2 and O2 of soil air to 5 m soil depth, a field study was conducted in the Calhoun Critical Zone Observatory, located in the subtropical climate of the Southern Piedmont of South Carolina, USA. Soil gas reservoirs were installed in ecosystems with three different land uses, each replicated three times: (i) reference hardwood stands that were never cultivated; (ii) currently cultivated plots; (iii) pine stands, which had been used for growing cotton in 19th century but were abandoned in about the 1930s and 1940s when they were regenerated with pines that are today 70–80 yr old. In addition to soil CO2 and O2 concentration measurements, soil gas samples were analyzed for Δ14C, δ13C, and δ18O. Stable carbon isotopic composition becomes lighter with the depth in soils of all three land uses: in the cultivated site δ13C decreases from –18‰ at 0.5 m to –21‰ at 5 m, in pine site from –22 to –25‰, and in hardwood from –21.5 to –24.5‰, respectively. Δ14C increased with depth from 40 to 60‰ in the top 0.5 m to about 80–140‰ at 5 m depending on land use. While surficial soils had relatively similar Δ14C in CO2, between 40 to 60‰ at 0.5 m, at 3 and 5 m, cultivated soils had the highest Δ14C, hardwood the lowest, and pine in between, a pattern that emphasizes the importance of contemporary respired CO2 in hardwood stands. Oxygen isotopic composition of CO2 did not change with depth, whereas free O2 was greatly enriched in lower horizons of forest soils, which we attribute to strong fractionation by respiration.


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Amundson, R, Stern, L, Baiseden, T, Wang, Y. 1998. The isotopic composition of soil and soil respired CO2 . Geoderma 82:83114.
Angert, A, Luz, B, Yakir, D. 2001. Fractionation of oxygen isotopes by respiration and diffusion in soils and its implications for isotopic composition of atmospheric O2 . Global Biogeochemical Cycles 15:871880.
Angert, A, Luz, B. 2001. Fractionation of oxygen isotopes by root respiration: Implications for the isotopic composition of atmospheric O2 . Geochimica et Cosmochemica Acta 65:16951701.
Billings, SA, Hirmas, D, Sullivan, PL, Lehmeier, CA, Bagchi, S, Min, K, Brecheisen, Z, Hauser, E, Stair, R, Flournoy, R, Richter, DD. 2018. Loss of deep roots limits biogenic agents of soil development that are only partially restored by decades of forest regeneration. Elem Sci Anth 6:34. doi:
Bloom, AA, Exbrayat, JF, van der Velde, IR, Feng, L, Williams, M. 2016. The decadal state of the terrestrial carbon cycle: Global retrievals of terrestrial carbon allocation, pools, and residence times. Proceedings of National Academy of Science 113(5):12851290.
Cherkinsky, A, Culp, RA, Dvoracek, DK, Noakes, JE. 2010. Status of the AMS facility at the University of Georgia. Nuclear Instruments and Methods in Physical Research B 258:867870.
Czimczik, CI, Trumbore, SE, Carbone, MS, Winston, GG. 2006. Changing sources of soil respiration with time since fire in boreal forest. Global Change Biology 12:957971.
De Camargo, PB, Trumbore, SE, Martinelli, LA, Davidson, EA, Nepstad, DC, Victoria, RL. 1999. Soil carbon dynamics in regrowing forest of eastern Amazonia. Global Change Biology 5:693702.
Dung, P, Shen, CD, Wang, N, Yi, WX, Ding, XF, Fu, DP, Liu, KX, Zhou, LP. 2010. Turnover rate of soil organic matter and origin of soil 14CO2 in deep soil from subtropical forest in dinghushan biosphere reserve, South China. Radiocarbon 52(2-3):14221434.
Dorr, H, Minnich, KO. 1986. Annual variation of the 14C content of soil CO2 . Radiocarbon 28(2A):338345.
Egan, J, Nickerson, N, Phillips, C, Risk, D. 2014. A numerical examination of 14CO2 chamber methodologies for sampling Ar the soil surface. Radiocarbon 56(3):11751188.
Gaudinski, JB, Trumbore, SE, Davidson, EA, Zheng, SH. 2000. Soil carbon cycling in a temperate forest: radiocarbon-based estimates of residence times, sequestration rates, and partitioning of fluxes. Biogeochemistry 51(1):3369.
Francey, RJ, Tans, PP. 1987. Latitudinal variation in oxygen-18 of atmospheric CO2 . Nature 327:495497.
Hahn, V, Hogberg, P, Buchhmann, N. 2006. 14C – a tool for separation of autotrophic and heterotrophic soil respiration. Global Change Biology 12:972982.
Hall, SJ, Silver, WL. 2013. Iron oxidation stimulates organic matter decomposition in humid tropical forest soils. Global Change Biology 19:28042813.
Hicks Pries, CE, Shuur, EAG, Crummer, KG. 2013. Thwaing permafrost increases old soil authotrophic respiration in tundra: Partitioning ecosystem respiration using δ13C and Δ14C. Global Change Biology 19:649661.
Hua, Q, Barbetti, M, Rakowski, AZ. 2013 Atmospheric radiocarbon for the period 1950–2010. Radiocarbon 55(4):20592072.
Koarashi, J, Hockaday, WC, Masiello, CA, Trumbore, SE. 2012. Dynamics of decadally cycling carbon in subsurface soil. J. Geophys. Res 117, G03033. doi:10.1029/2012JG002034.
Koarashi, J, Iida, T, Moriizumi, J, Agano, T. 2004. Evaluation of 14C abundance in soil respiration using accelerator mass spectrometry. Journal of Environmental Radioactivity 75:117132.
Kyzyakov, Y. 2006. Sources of CO2 efflux from soil, review of partitioning methods. Soil Biology & Biochemistry 38:425448.
Kuzyakov, Y, Larionova, AA. 2005. Root and rhizomicrobial respiration: A review of approaches to estimate respiration by autotrophic organisms in soil. J. Plant Nutr. Soil Sci 168:503520.
Luo, Y, Zhou, X. 2006. Soil Respiration and Environment. Elsevier. 328 p.
Luz, B, Barkan, E. 2011. The isotopic composition of atmospheric O2 . Global Biogeochemical Cycles 25 GB3001. doi.10.1029/2010GB003883.
Mobley, ML, Lajtha, K, Kramer, MG, Bacon, AR, Heine, PR, Richter, DdeB. 2015. Surficial gains and subsoil losses of soil carbon and nitrogen during secondary forest development. Global Change Biology 21:986996.
Reimer, PJ, Brown, TA, Reimer, RW. 2004. Discussion: Reporting and calibration of post bomb 14C data. Radiocarbon 46(3):12991304.
Phillips, CL, McFarlane, , Risk, D, Desai, AR. 2013. Biological and physical influence on soil 14CO2 seasonal dynamics in temperate hardwood forest. Biogeosciences 10:79998012.
Richter, DdeB, Billings, SA. 2015. “One physical system”: Tansley’s ecosystem as Earth’s critical zone. New Phytologist 206:900912.
Richter, DD, Markewitz, D, Trumbore, SE, Wells, CG. 1999. Rapid accumulation and turnover of soil carbon in a re-establishing forest. Nature 400:5658.
Shuur, EAG, Trumbore, SE. 2006 Partitioning sources of soil respiration in boreal spruce forest using radiocarbon. Global Change Biology 12:165176.
Stuiver, M, Polach, HA. 1977. Reporting of 14C data. Radiocarbon 19(3):355363.
Trumbore, SE. 2000. Age of soil organic matter and soil respiration: radiocarbon constraints on belowground C dynamics. Ecological Applications 10(2):399411.
Wang, Y, Hu, C, Ming, H, Oenema, O, Schaefer, DA, Dong, W, Zhang, Y, Li, X. 2014. Methane, carbon dioxide, and nitrous oxide fluxes in soil profile under a winter wheat-summer maize rotation in the North China Plain. PLos One 9(6):e98445.


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Carbon and Oxygen Isotope Composition in Soil Carbon Dioxide and Free Oxygen within Deep Ultisols at the Calhoun CZO, South Carolina, USA

  • Alexander Cherkinsky (a1), Zachary Brecheisen (a2) and Daniel Richter (a2)


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