Fig. 2. Potential biases in the quantification of soil C pools due to preferential soil sampling:
Plots with a local accumulation of coarse woody debris and soil pitswith a high density of
decaying coarse roots are avoided in field campaigns. Left picture: thinning residues in a
young spruce forest in the Vienna woods (courtesy: Rainer Reiter), right picture: a high
content of coarse roots in the soil samples collected by an auger profile.