Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-29T02:48:18.059Z Has data issue: false hasContentIssue false

A Numerical Examination of 14CO2 Chamber Methodologies for Sampling at the Soil Surface

Published online by Cambridge University Press:  26 July 2016

Jocelyn Egan*
Affiliation:
Dept. of Earth Sciences, St. Francis Xavier University, 1 West Street, Antigonish, Nova Scotia B2G 2W5, Canada
Nick Nickerson
Affiliation:
Dept. of Earth Sciences, Dalhousie University, 1459 Oxford Street, Halifax, Nova Scotia B3H 4R2, Canada
Claire Phillips
Affiliation:
Dept. of Crop and Soil Science, Oregon State University, Corvallis, Oregon 97331, USA
Dave Risk
Affiliation:
Dept. of Earth Sciences, St. Francis Xavier University, 1 West Street, Antigonish, Nova Scotia B2G 2W5, Canada
*
Corresponding author. Email: [email protected].

Abstract

Radiocarbon is an exceptionally useful tool for studying soil-respired CO2, providing information about soil carbon turnover rates, depths of production, and the biological sources of production through partitioning. Unfortunately, little work has been done to thoroughly investigate the possibility of inherent biases present in current measurement techniques, like those present in δ13CO2 methodologies, caused by disturbances to the soil's natural diffusive regime. This study investigates the degree of bias present in four 14C sampling chamber methods using a three-dimensional numerical soil-atmosphere CO2 diffusion model. The four chambers were tested in an idealized, surrogate reality by assessing measurement bias with varying Δ14C and δ13C signatures of production, collar lengths, soil biological productivity rates, and soil diffusivities. The static and Iso-FD chambers showed almost no isotopic measurement bias, significantly outperforming dynamic chambers, which demonstrated biases up to 200‰ in some modeled scenarios. The study also showed that 13C and 14C diffusive fractionation are not a constant multiple of one another, but that the δ13C correction still works in diffusive scenarios because the change in fractionation is not large enough to impact measured Δ14C values during chamber equilibration.

Type
Articles
Copyright
Copyright © 2014 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amundson, R, Stern, L, Baisden, T, Wang, Y. 1998. The isotopic composition of soil and soil-respired CO2 . Geoderma 82(1–3):83114.Google Scholar
Bond-Lamberty, B, Bronson, D, Bladyka, E, Gower, ST. 2011. A comparison of trenched plot techniques for partitioning soil respiration. Soil Biology and Biochemistry 43(10):2108–14.Google Scholar
Bowling, DR, Massman, WJ, Schaeffer, SM, Burns, SP, Monson, RK, Williams, MW. 2009. Biological and physical influences on the carbon isotope content of CO2 in a subalpine forest snowpack, Niwot Ridge, Colorado. Biogeochemistry 95(1):3759.Google Scholar
Cerling, TE, Solomon, DK, Quade, J, Bowman, JR. 1991. On the isotopic composition of carbon in soil carbon dioxide. Geochimica et Cosmochimica Acta 55(11):3403–5.Google Scholar
Creelman, C, Nickerson, N, Risk, D. 2013. Quantifying lateral diffusion error in soil CO2 respiration estimates using numerical modeling. Soil Science Society of America Journal 77(3):699–8.Google Scholar
Davidson, GR. 1995. The stable isotopic composition and measurement of carbon in soil CO2 . Geochimica et Cosmochimica Acta 59(12):2485–9.CrossRefGoogle Scholar
Drake, JE, Oishi, AC, Giasson, M-A, Oren, R, Johnsen, KH, Finzi, AC. 2012. Trenching reduces soil heterotrophic activity in a loblolly pine (Pinus taeda) forest exposed to elevated atmospheric [CO2] and N fertilization. Agricultural and Forest Meteorology 165:4352.CrossRefGoogle Scholar
Gaudinski, JB, Trumbore, SE, Davidson, EA, Zheng, S. 2000. Soil carbon cycling in a temperate forest: radiocarbon-based estimates of residence times, sequestration rates and partitioning fluxes. Biogeochemistry 51(1):3369.CrossRefGoogle Scholar
Gomez-Casanovas, N, Matamala, R, Cook, DR, Gonzalez-Meier, MA. 2012. Net ecosystem exchange modifies the relationship between the autotrophic and heterotrophic components of soil respiration with abiotic factors in prairie grasslands. Global Change Biology 18(8):2532–45.CrossRefGoogle Scholar
Hahn, V, Högberg, P, Buchmann, N. 2006. 14C – a tool for separation of autotrophic and heterotrophic soil respiration. Global Change Biology 12(6):972–82.CrossRefGoogle Scholar
Hanson, PJ, Edwards, NT, Garten, CT, Andrews, JA. 2000. Separating root and microbial contributions to soil respiration: a review of methods and observations. Biogeochemistry 48(1):115–48.Google Scholar
Hicks Pries, CE, Schurr, EAG, Crummer, KG. 2013. Thawing permafrost increases old soil and autotrophic respiration in tundra: partitioning ecosystem respiration using δ13C and Δ14C. Global Change Biology 19(2):649–61.Google Scholar
Högberg, P, Nordren, A, Buchmann, N, Taylor, A, Ekblad, A, Högberg, M, Nyberg, G, Ottosson-Löfvenius, M, Read, D. 2001. Large-scale forest girdling shows that current photosynthesis drives soil respiration. Nature 411(6839):789–92.CrossRefGoogle ScholarPubMed
Kayler, Z, Sulzman, E, Rugh, W, Mix, A, Bond, B. 2010. Characterizing the impact of diffusive and advective soil gas transport on the measurement and interpretation of the isotopic signal of soil respiration. Soil Biology and Biochemistry 42(3):435–44.CrossRefGoogle Scholar
Ku, H. 1966. Notes on the use of propagation of error formulas. Journal of Research of the National Bureau of Standards Section C: Engineering and Instrumentation 70(4):263–73.Google Scholar
Kuzyakov, Y. 2006. Sources of CO2 efflux from soil and review of partitioning methods. Soil Biology and Biochemistry 38(4):425–48.Google Scholar
Lee, M-S, Nakane, K, Nakatsubo, T, Koizumi, H. 2003. Seasonal changes in the contribution of root respiration to total soil respiration in a cool-temperate deciduous forest. Plant Soil 255(1):311–8.Google Scholar
Levin, I, Hesshaimer, V. 2000. Radiocarbon—a unique tracer of global carbon cycle dynamics. Radiocarbon 42(3):6980.Google Scholar
Moyes, AB, Gaines, SJ, Siegwolf, RTW, Bowling, DR. 2010. Diffusive fractionation complicates isotopic partitioning of autotrophic and heterotrophic sources of soil respiration. Plant, Cell and Environment 33(11):1804–19.CrossRefGoogle ScholarPubMed
Nickerson, N, Risk, D. 2009a. Physical controls on the isotopic composition of soil respired CO2 . Journal of Geophysical Research 114(G1):G01013.Google Scholar
Nickerson, N, Risk, D. 2009b. A numerical evaluation of chamber methodologies used in measuring the δ13C of soil respiration. Rapid Communications in Mass Spectrometry 23(17):2802–10.Google Scholar
Nickerson, N, Egan, J, Risk, D. 2013. Iso-FD: a novel method for measuring the isotopic signature of surface flux. Soil Biology and Biochemistry 62:99–6.Google Scholar
Ohlsson, KEA. 2010. Reduction of bias in static closed chamber measurements of δ13C in soil CO2 flux. Rapid Communications in Mass Spectrometry 24(2):180–4.Google Scholar
Phillips, CL, Nickerson, N, Risk, D, Kayler, Z, Andersen, C, Mix, AC, Bond, BJ. 2010. Soil moisture effects on the carbon isotope composition of soil respiration. Rapid Communications in Mass Spectrometry 24(9):1271–80.CrossRefGoogle ScholarPubMed
Phillips, CL, McFarlane, K, Risk, D, Desai, AR. 2013. Biological and physical influences on soil 14CO2 seasonal dynamics in a temperate hardwood forest. Biogeosciences Discussions 10:10,72158.Google Scholar
Rayment, MB, Jarvis, PG. 1997. An improved open chamber system for measuring soil CO2 effluxes in the field. Journal of Geophysical Research – Atmosphere 102(D24):28,77984.Google Scholar
Risk, D, Kellman, L. 2008. Isotopic fractionation in non-equilibrium diffusive environments. Geophysical Research Letters 35(2):L02403.Google Scholar
Risk, D, Nickerson, N, Creelman, C, McArthur, G, Owens, J. 2011. Forced diffusion soil flux: a new technique for continuous monitoring of gas efflux. Agricultural Forest Meteorology 151(12):1622–31.Google Scholar
Risk, D, Nickerson, N, Phillips, CL, Kellman, L, Moroni, M. 2012. Drought alters respired δ13CO2 from autotrophic, but not heterotrophic soil respiration. Soil Biology and Biochemistry 50:26–2.Google Scholar
Schuur, EAG, Trumbore, SE. 2006. Partitioning sources of soil respiration in boreal black spruce forest using radiocarbon. Global Change Biology 12(2):165–76.Google Scholar
Singh, B, Nordgren, A, Lofvenius, MO, Högberg, MN, Mellander, P-E, Högberg, P. 2003. Tree root and soil heterotrophic respiration as revealed by girdling of boreal Scots pine forest: extending observations beyond the first year. Plant, Cell and Environment 26(8):1287–96.Google Scholar
Southon, JR. 2011. Are the fractionation corrections correct: Are the isotopic shifts for 14C/12C ratios in physical processes and chemical reactions really twice those for 13C/12C? Radiocarbon 53(4):691704.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.Google Scholar
Trumbore, S. 2000. Age of soil organic matter and soil respiration: radiocarbon constraints on belowground C dynamics. Ecological Applications 10(2):399–11.CrossRefGoogle Scholar
Trumbore, S. 2006. Carbon respired by terrestrial ecosystems – recent progress and challenges. Global Change Biology 12(2):141–53.CrossRefGoogle Scholar
Venterea, RT, Baker, JM. 2008. Effects of soil physical nonuniformity on chamber-based gas flux estimates. Soil Science Society of America Journal 72(5):1410–7.Google Scholar
Wang, Y, Amundson, R, Trumbore, S. 1994. A model for soil 14CO2 and its implications for using 14C to date pedogenic carbonate. Geochimica et Cosmochimica Acta 58(1):393–9.Google Scholar