We have studied in this paper the morphological, chemical and physico-chemical characteristics of some soils (Cambisoles húmicos y C. dístricos) after ten months of a forest fire and also in unburned soils. We observed that in the superficial layers of the soil pH, CEC, exchangeable Ca2+ and K+, increases because of the ashes of the burnt plants (Pinus pinaster Ait). We deduced that fire was of moderate intensity because of the significative correlation between C and N; it is also observed in this kind of soils and increase in the relation FeD to FeT due to the liberation of iron fundamentally in the surface of the soil layer.
