The influence of periodic fires on the high Guinean savannas and the carbon stock in Cameroon

Abstract

The influence of periodic fires in the high Guinean savannas of Cameroon on woody plants and carbon stock is poorly documented. To fill this gap, work was carried out in the high Guinean savannas of Cameroon with the aim of contributing to the assessment of the effects of periodic fires on the woody cover and the carbon stock. The methodology used consists of carrying out semi-structured household surveys and floristic inventories in the Arrondissement of Ngaoundéré III and Ngan’ha, in the Department of Vina. A total of 50 households were interviewed at a rate of 25 per Borough according to a questionnaire prepared beforehand. For the botanical inventories, 02 types of savannah were selected: regularly burnt savannas (shrub savannas, wooded savannas) and those not burned for at least 10 years (shrub savannas, tree savannas). The choice of control savannas was made according to the indications of the peasants. In each of them, the 1km x 20m transects were covered and the diameter at breast height (dbh) of the woody plants was measured using a dbh meter at 1.3 m from the ground for large trees. and at 30 or 50 cm from the ground for shrubs and shrubs. The results show that climate change is palpable in the area. The rains are increasingly rare, the drought has become severe and the agricultural calendar is no longer respected. The specific diversity has become relatively low with 51 species having been inventoried, divided into 46 genera and 23 families. Savannahs that are not burnt produce more biomass than those that are burnt. The perfect illustration is given by the non-burnt tree savannah of Ngaoundere III with an above-ground and root biomass of 102.23 t / ha and 20.70 t / ha respectively. Annona senegalensis (1.27 tC / ha) is the species contributing massively to carbon sequestration in the high savannas of the Vina. Thus, by acting on the availability of plant biomass, fires contribute to the erosion of biodiversity. Adequate measures are urgently needed to limit bushfires.