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This article in SSSAJ

  1. Vol. 66 No. 4, p. 1151-1158
    Received: May 28, 2001

    * Corresponding author(s): shoji@fr.a.u-tokyo.ac.jp


Vertical distributions of carbon dioxide diffusion coefficients and production rates in forest soils

  1. Shoji Hashimoto * and
  2. Masakazu Suzuki
  1. Lab. of Forest Hydrology and Erosion Control Engineering, Graduate School of Agricultural and Life Sciences, The Univ. of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan


In this study, we developed a new method for evaluating vertical profiles of CO2 gas diffusivity and CO2 gas production in soil samples. The CO2 flux at the boundary and the steady-state CO2 gas profile are measured under two boundary gas conditions.The differential form of Fick's second law can then be used to calculate the gas diffusion coefficients and CO2 production rate. This method was applied to an undisturbed forest soil sample in the laboratory. Both gas diffusion coefficients and CO2 production rates decreased with increasing depth. The relative gas diffusion coefficients ranged between 0.03 and 0.15, and the CO2 production rates ranged between 2.1 × 10−8 and 4.7 × 10−8 kg CO2 m3 s−1 at 20°C. Unsteady changes in the CO2 concentration profile in the soil column, and flux from the soil surface were successfully simulated with these values.

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Copyright © 2002. Soil Science SocietyPublished in Soil Sci. Soc. Am. J.66:1151–1158.