Seen 190923 times
© Nathalie Petrel / ONF
After the humus layer has been collected, a cylinder is driven into each subsequent mineral layer to take a core sample.
The proportion of fine soil and rocks can then be determined for a standardised volume.
After the samples have been analysed, the available amounts of different chemical elements they contain will be calculated. Only the chemical elements in the fine soil can be used by the trees.