Soil properties differently influence estimates of soil CO2 efflux from three chamber-based measurement systems

  • Authors: Butnor, John R.; Johnsen, Kurt H.; Maier, Chris A.
  • Publication Year: 2005
  • Publication Series: Miscellaneous Publication
  • Source: Biogeochemistry 73: 283-301


Soil C02 efflux is a major component of net ecosystem productivity (NEP) of forest systems. Combining data from multiple researchers for larger-scale modeling and assessment will only be valid if their methodologies provide directly comparable results. We conducted a series of laboratory and field tests to assess the presence and magnitude of soil CO2 efflux measurement system x environment interactions. Laboratory comparisons were made with a dynamic, steady state C02 flux generation apparatus, wherein gas diffusion drove flux without creating pressure differentials through three artificial soil media of varying air-filled porosity. under these conditions, two closed systems (Li-6400-2009 and SRC-1) exhibited errors that were dependent on physical properties of the artificial media. The open system (ACES) underestimated C02 flux. However, unlike the two other systems. the ACES results could be corrected with a single calibration equation that was unaffected by physical differences in artificial media. Both scale and rank changes occurred among the measurement systems across four sites. Our work clearly shows that soil C02 efflux measurement system x environment interactions do occur and can substantially impact estimates of soil COz efflux. Until reliable calibration techniques are developed and applied, such interactions make direct comparison of published rates, and C budgets estimated using such rates, difficult.

  • Citation: Butnor, John R.; Johnsen, Kurt H.; Maier, Chris A. 2005. Soil properties differently influence estimates of soil CO2 efflux from three chamber-based measurement systems. Biogeochemistry 73: 283-301
  • Keywords: Calibration, CO2 efflux, diffusivity, porosity, soil CO2 efflux, soil respiration
  • Posted Date: April 1, 1980
  • Modified Date: August 22, 2006
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
    • To view this article, download the latest version of Adobe Acrobat Reader.