Quantitative changes of SOM are a ramification of two effects of fire: i) the removal of most or all of the litter layer and, possibly, some organics from the upper few centimetres of mineral soil, the only ones that really experience high temperatures; and ii) the input of charred materials from the scorched stems and crowns (Alexis et al., 2007). Net fire-induced gain or loss of SOM results from the dominance of one of these processes. The C balance of any study focused to assess such gain or loss is highly affected by the sampling procedure.