Plant and Soil

, Volume 187, Issue 2, pp 135–145 | Cite as

Detecting changes in soil carbon in CO2 enrichment experiments

  • Bruce A. Hungate
  • Robert B. Jackson
  • Christopher B. Field
  • F. Stuart ChapinIII
Quantitative Analysis of Total Carbon Budget


After four growing seasons, elevated CO2 did not significantly alter surface soil C pools in two intact annual grasslands. However, soil C pools in these systems are large compared to the likely changes caused by elevated CO2. We calculated statistical power to detect changes in soil C, using an approach applicable to all elevated CO2 experiments. The distinctive isotopic signature of the fossil-fuel-derived CO2 added to the elevated CO2 treatment provides a C tracer to determine the rate of incorporation of newly-fixed C into soil. This rate constrains the size of the possible effect of eievated CO2 on soil C. Even after four years of treatment, statistical power to detect plausible changes in soil C under elevated CO2 is quite low. Analysis of other elevated CO2 experiments in the literature indicates that either CO2 does not affect soil C content, or that reported CO2 effects on soil C are too large to be a simple consequence of increased plant carbon inputs, suggesting that other mechanisms are involved, or that the differences are due to chance. Determining the effects of elevated CO2 on total soil C and long-term C storage requires more powerful experimental techniques or experiments of longer duration.

Key words

annual grassland carbon-13 carbon dioxide carbon storage serpentine soil soil carbon statistical power 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Arnone, JA and Körner, Ch 1995 Soil and biomass carbon pools in model communities of tropical plants under elevated CO2. Oecologia 104, 61–71.Google Scholar
  2. Bowes, G 1991 Growth at elevated CO2: photosynthetic responses mediated through RUBISCO: Commissioned review. Plant Cell Environ 14, 795–806.Google Scholar
  3. Cambardella, CA and Elliot, ET 1992 Particulate soil organic-matter changes across a grassland cultivation sequence. Soil Sci. Soc. Am. J. 56, 777–783.Google Scholar
  4. Cardon Z G 1996 Influence of rhizodeposition under elevated CO2 on plant nutrition and soil organic matter. Plant and Soil 187.Google Scholar
  5. Chiariello 1989 Phenology of California Grassland. In Grassland Structure and Function: California Annual Grassland, Eds. LFHuenneke and HAMooney. pp 47–58. Kluwer Academic Publishers, Dordrecht, the Netherlands.Google Scholar
  6. Field, CB, ChapinIII, FS, Chiariello, NR, Holland, EA and Mooney, HA 1996 The Jasper Ridge CO2 experiment: design and motivation. In Ecosystem Responses to Elevated CO2. Eds. GKoch and HMooney. pp 121–145. Academic Press, San Diego, USA.Google Scholar
  7. Hickman, JC 1993 The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, USA. 1400 p.Google Scholar
  8. Huenneke, LF, Hamburg, SP, Koide, R, Mooney, HA and Vitousek, PM 1990 Effects of soil resources on plant invasion and community structure in Californian serpentine grassland. Ecology 71, 478–491.Google Scholar
  9. Ineson P, Cortrufo M F, Bol R, Harkness D D and Hartwig U 1996 Quantification of soil carbon inputs under elevated CO2: C3 plants in a C4 soil. Plant and Soil 187.Google Scholar
  10. Jackson, LE, Strauss, RB, Firestone, MK and JWBartolome 1990 Influence of tree canopies on grassland productivity and nitrogen dynamics in deciduous oak savanna. Agric. Ecosys. Environ. 32, 89–105.CrossRefGoogle Scholar
  11. Jackson, RB, Sala, OE, Field, CB and Mooney, HA 1994 CO2 alters water use, carbon gain, and yield for the dominant species in a natural grassland. Oecologia 98, 257–262.Google Scholar
  12. Johnson, DW, Geisinger, DR, Walker, RF, Newman, J, Vose, JM, Elliot, K and Ball, JT 1994 Soil pCO2, soil respiration, and root activity in CO2-fumigated and nitrogen-fertilized ponderosa pine. Plant and Soil 165, 129–138.Google Scholar
  13. Leavitt, SW, Paul, EA, Kimball, BA, Hendrey, GR, Mauney, JR, Rauschkolb, R, Rogers, H, Lewin, KF, Nagy, J, Pinter, PJ and Johnson, HB 1994 Carbon isotope dynamics of free-air CO2-enriched cotton and soils. Agric. Forest Meteor. 70, 87–101.CrossRefGoogle Scholar
  14. Lekkerkerk, LJA, Van DeGeijn, SC and VanVeen, JA 1990 Effects of elevated atmospheric CO2-levels on the carbon economy of a soil planted with wheat. In Soils and the Greenhouse Effect. Ed. AFBouwman. pp 423–429. John Wiley and Sons, Chichester, UK.Google Scholar
  15. Long, SP and Drake, BG 1992 Photosynthetic CO2 assimilation and rising atmospheric CO2 concentrations. In Crop Photosynthesis: Spatial and Temporal Determinants. Eds. NRBaker and HThomas. pp 69–103. Elsevier Science Publisers B. V., Amsterdam, the Netherlands.Google Scholar
  16. Luo Y, Jackson R B, Field C B and Mooney H A 1996 Elevated CO2 increases belowground respiration in California grasslands. Oecologia (In press).Google Scholar
  17. Mooney, HA, Drake, BG, Luxmoore, RJ, Oechel, WC and Pitelka, LF 1991 Predicting ecosystem responses to elevated CO2 concentrations. BioScience 41, 96–104.Google Scholar
  18. O'Leary, MH 1981 Carbon isotope fractionation in plants. Phytochemistry 20, 553–567.CrossRefGoogle Scholar
  19. Osenberg, CW, Schmitt, RJ, Holbrook, SJ, Abu-Saba, KE and Flegal, AR 1994 Detection of environmental impacts: natural variability, effect size, and power analysis. Ecol. Appl. 4, 16–30.Google Scholar
  20. Owensby, CE, Coyne, PI, Ham, JM, Auen, L and Knapp, AK 1993 Biomass production in a tallgrass prairie ecosystem exposed to ambient elevated CO2. Ecol. Appl. 3, 644–653.Google Scholar
  21. Owensby, CE, Auen, LM and Coyne, PI 1994 Biomass production in a nitrogen-fertilized, tallgrass prairie ecosystem exposed to ambient and elevated levels of CO2. Plant and Soil 165, 105–113.Google Scholar
  22. Parton, WJ, Schimel, DS, Cole, CV and Ojima, DS 1987 Analysis of factors controlling soil organic matter levels in Great Plains grasslands. Soil Sci. Soc. Am. J. 51, 1173–1179.Google Scholar
  23. Parton, WJ, Scurlock, JMO, Ojima, DS, Schimel, DS, Hall, DO and Members, SG 1995 Impact of climate change on grassland production and soil carbon worldwide. Global Change Biol. 1, 13–22.Google Scholar
  24. Rice, CW, Garcia, FO, Hampton, CO and Owensby, CE 1994 Soil microbial response in tallgrass prairie to elevated CO2. Plant and Soil 165, 67–75.Google Scholar
  25. Rogers, HH and Prior, SP 1992 Cotton root and rhizosphere responses to Free-Air CO2 Enrichrnent. Crit. Rev. Plant Sci. 11, 251–263.Google Scholar
  26. Ross, DJ, Tate, KR and Newton, PCD 1995 Elevated CO2 and temperature effects on soil carbon and nitrogen cycling in ryegrass/white clover turves of an Endoaquept soil. Plant and Soil 176, 37–49.Google Scholar
  27. Schlesinger, WH 1991 Biogeochemistry: An Analysis of Global Change. Academic Press, San Diego, USA.Google Scholar
  28. Townsend, AR, Vitousek, PM and Trumbore, SE 1995 Soil organic matter dynamics along gradients in temperature and land use on the island of Hawaii. Fcology 76, 721–733.Google Scholar
  29. Winer, BJ, Brown, DR and Michels, KM 1991 Statistical Principles in Experimental Design. McGraw-Hill Publishers, New York, USA.Google Scholar
  30. Wood, CW, Torbert, HA, Rogers, HH, Runion, GB and Prior, SA 1994 Free-air CO2 enrichment effects on soil carbon and nitrogen. Agric For. Meteor. 70, 103–116.CrossRefGoogle Scholar
  31. Zak, DR, Pregitzer, KS, Curtis, PS, Teeri, JA, Fogel, R and Randlett, DA 1993 Elevated atmospheric CO2 and feedback between carbon and nitrogen cycles. Plant and Soil 11, 105–117.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Bruce A. Hungate
    • 1
  • Robert B. Jackson
    • 2
  • Christopher B. Field
    • 3
  • F. Stuart ChapinIII
    • 1
  1. 1.Department of Integrative BiologyUniversity of CaliforniaBerkeleyUSA
  2. 2.Department of Biological SciencesStanford UniversityStanfordUSA
  3. 3.Department of Plant BiologyCarnegie Institution of WashingtonStanfordUSA

Personalised recommendations