Ia. Janssens et R. Ceulemans, Spatial variability in forest soil CO2 efflux assessed with a calibrated soda lime technique, ECOL LETT, 1(2), 1998, pp. 95-98
Accurate estimates of soil CO2 afflux are important in the current discussi
on on the carbon balance of forests, and can be used to validate models and
remotely sensed data. Due to the typically large spatial variability, larg
e sample numbers are required to estimate mean forest soil CO2 efflux with
reasonable confidence intervals. Most infrared gas analysis (IRGA) systems
are not well suited to simultaneously produce daily means and handle this s
patial variability problem. The soda lime technique gives daily means and a
llows the required large sample numbers, but is less accurate than the IRGA
systems. Using an elaborate cross-calibration, we tried to combine the acc
uracy of an IRGA method with the spatial integration potential of the soda
lime technique. This paper reports on the calibration technique used to imp
rove the accuracy of the soda lime technique and confirms the spatial varia
bility in soil CO2 efflux in a heterogeneous forest.