A Calibration System for Soil Carbon Dioxide-Efflux Measurement Chambers
Description and Application
Britta Widéna and
Anders Lindroth*,b
a Department for Production Ecology, Faculty of Forestry, P.O. Box 7042, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden
b Department of Physical Geography and Ecosystems Analysis, P.O. Box 118, Lund University, 221 00, Lund, Sweden
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Fig. 1. The calibration system with parts of the closed-dynamic system (Li-Cor 6200-09), and open-dynamic system.
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Fig. 2. The CO2 flux measured by the closed-dynamic system compared with the reference flux for three different types of soil.
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Fig. 3. The CO2 flux measured by the open system and the flux from the calibration box outside the chamber, relative to the reference flux at increasing pressure difference between the inside and the outside of the chamber. Also included is the relative flux at different pressure differences as measured by Fang and Moncrieff (1998).
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Fig. 4. The CO2 flux measured by the open chamber relative to the expected CO2 flux as the soil air-filled volume changes, using different types of soil.
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Fig. 5. The CO2 efflux from the calibration box at different inside CO2 concentrations. First, when the open chamber, which covered the whole surface, was on top and running and secondly when no chamber was present.
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Copyright © 2003 by the Soil Science Society of America.
