Abstract ATANASSOVA, I., M. TEOHAROV and P. IVANOV, 2009. Characterisation of a fire affected catena sequence from Lyulin Mountain, Bulgaria. Bulg. J. Agric. Sci., We analysed the effects of a forest fire having occurred in the late summer of 2007 on major characteristics and properties of surface soils and soil profiles characterised as a catena sequence. The objectives of our study were to carry out a detailed morphological description of the individual soil profiles on the ridge and slopes of Lyulin mountain and analyse other chemical, physico-chemical and mineralogical characteristics in the surface horizons mostly affected by fire. Our key findings are: (1) changes were observed in the surface depths and concern mainly the soil organic carbon, primary minerals mineralogy and texture; (2) no major changes in the cation exchange capacity and exchangeable Ca and Mg cation composition between the surface and the lower depths of the soil profiles were found and no additional release of bases as a result of burning was accounted for; (3) total organic carbon increased in all the burnt soils, due to partially combusted organic remnants. As a result of the detailed analysis of the catena sequence we conclude that the fire that occurred was not of high severity and had mainly affected the ridge of the mountain and the surface depths of the higher parts of the hillslope
