The advantages of suitable coding of plant formations in databases on fires are obvious for research programmes concerning the notion of risk and the mapping of risks. According to the CEMAGREF report, there is a strong correlation between the occurrence of large fires and the vegetation factor at various significance thresholds depending on whether the vegetation is maquis and garrigue with deciduous plants (0.1 per cent), maquis and garrigue with no trees (1 per cent,) or coniferous garrigue (5 per cent).