Biogeochemistry

, Volume 77, Issue 1, pp 91–116

Long-term Effects of Free Air CO2 Enrichment (FACE) on Soil Respiration

  • E. S. Bernhardt
  • J. J. Barber
  • J. S. Pippen
  • L. Taneva
  • J. A. Andrews
  • W. H. Schlesinger
Article

DOI: 10.1007/s10533-005-1062-0

Cite this article as:
Bernhardt, E.S., Barber, J.J., Pippen, J.S. et al. Biogeochemistry (2006) 77: 91. doi:10.1007/s10533-005-1062-0

Abstract

Emissions of CO2 from soils make up one of the largest fluxes in the global C cycle, thus small changes in soil respiration may have large impacts on global C cycling. Anthropogenic additions of CO2 to the atmosphere are expected to alter soil carbon cycling, an important component of the global carbon budget. As part of the Duke Forest Free-Air CO2 Enrichment (FACE) experiment, we examined how forest growth at elevated (+200 ppmv) atmospheric CO2 concentration affects soil CO2 dynamics over 7 years of continuous enrichment. Soil respiration, soil CO2 concentrations, and the isotopic signature of soil CO2 were measured monthly throughout the 7 years of treatment. Estimated annual rates of soil CO2 efflux have been significantly higher in the elevated plots in every year of the study, but over the last 5 years the magnitude of the CO2 enrichment effect on soil CO2 efflux has declined. Gas well samples indicate that over 7 years fumigation has led to sustained increases in soil CO2 concentrations and depletion in the δ13C of soil CO2 at all but the shallowest soil depths.

Keywords

Carbon dioxide enrichmentDel 13CDuke ForestFACESoil CO2Soil respiration

Copyright information

© Springer 2006

Authors and Affiliations

  • E. S. Bernhardt
    • 1
  • J. J. Barber
    • 2
  • J. S. Pippen
    • 3
  • L. Taneva
    • 4
  • J. A. Andrews
    • 5
  • W. H. Schlesinger
    • 3
  1. 1.Department of Biology, LSRC B234Duke UniversityDurhamUSA
  2. 2.Department of Mathematical SciencesMontana State UniversityBozemanUSA
  3. 3.Nicholas School of the Environment and Earth SciencesDuke UniversityDurhamUSA
  4. 4.Department of Biological SciencesUniversity of Illinois at ChicagoChicagoUSA
  5. 5.LockeLiddell & SappHoustonUSA