Paramètres climatiques déterminant les caractéristiques du feu dans une savane guinéenne (réserve de Lamto, Côte d’Ivoire)

The recurring use of fire in the Guinean savanna underscores the need to identify the local climatic parameters that predict fire behavior. This study was conducted in 2013–2016, with three experimental fire periods (early, mid and late season) each year. The objective was to identify, among the climatic parameters of the year before the fire (PCAs), during the month of the fire (PCMs), and during the fire (PCDs), those that best predict fuel and fire characteristics. Mixed-effects multiple regressions and model selection showed that PCAs do not influence fuel load and fire intensity. Among the PCMs, the number of days between the last rain > 1 mm and the fire determines fuel humidity. Moreover, the more it rains during the month of the fire and/or in the 10 days before, the lower the intensity. Among the PCDs, air humidity is the key factor: the lower it is, the faster the fire spreads and the more intense it is. Only PCMs determine fire intensity. This study highlights that rainfall occurring shortly before a fire determines fire intensity through its effect on litter moisture content. These results open up new perspectives for modeling the spread of fires in the Guinean savanna.