Susceptibility to Fire (Case the Forest of Chettabah, Algeria)

This work consists to evaluate the sensitivity of the Holm oak and Aleppo pine forestry vegetation against the fire in the region of Constantine (north-east Algerian). The shrub and herbaceous stratums are the most vulnerable and inflammables. The parameters analysis and the follow up of the foliage water content of the flammability and the combustibility is achieved during whole the year on the evergreen oak, Aleppo pine and a few number of secondary kinds of its floristic accompanying. The sensitivity of the foliage depend on the species, it is optimal during the summer. The time of flammability varies between 30 and 120 seconds in winter, even though the combustibility is between 40 and 500 seconds for the same periods. Theses variations allows to get noticed of the homogeneous groups for the litter, the bark and the other species like Asparagus acutifolium, Astragalus armatus Calycotome spinosa Ampelodesma mauritanicum, Cistus villosus, Pistacia lentiscus and Arbutus unedo. A classification of the different vegetables species is established according to studied parameters of the sensitivity degree. The air maximum temperature of the month is the hottest and is varied between (39-42°C). During the summer, the flammability is 60 seconds for Pinus halepensis and 20 seconds for Quercus ilex concerning the combustibility; it oscillates respectively between 200-400 seconds and 200-300 seconds for the two forestry species. The risk calculation by the CEMAGREF method is higher in the summer. The combustibility knowledge of the flammability is due to the foliage water content, linked to the species and the vegetable formation that are transposable for the vegetation map which allowed to class the planting by big flammability categories.