IMPACT OF CASHEW PLANTATION ON CARBON STOCK IN THE FOREST-SAVANNA TRANSITION ZONE (NORTH-EAST COTE D'IVOIRE)

The increasing world demand for cashew (Anacardium occidentale L.) nuts and by-products generates rapid expansion of cashew cultivation across West-African countries especially in Cote d'Ivoire. This has created wealth for many smallholders. This is not to mention the pressure on forest-savanna transition zone. The aim of this study is to assess the impact of cashew production on carbon stocks. Vegetation inventory and soil sampling (0-20cm and 20-40cm) were done to estimate the above and below ground as well as soil carbon for savanna, forest and cashew plantain at different growing stages. The total carbon stocks in Mg C ha-1 were low in cashew plantations, where mature stands had 21.826 ± 3.23 (Mean ± SE), young 25.927 ± 6.53 and juvenile 16.732 ± 2.96 compared with natural vegetation (forest/woodland 64.375 ± 12.43, tree savannas 23.94 ± 3.3 and tree/shrub savannas 21.012 ± 10.12). There was no significant difference in soil organic carbon and total soil carbon stocks under different land use types, except between forest (24.67 ± 5.37 Mg C ha-1) and tree/shrub savanna (8.92 ± 1.57 Mg C ha-1). This implies that cashew expansion is of higher threat to more woody vegetation which has serious implication in terms of conservation and carbon sequestration. There is therefore a need for a more sustainable management approach to cashew agriculture practices to ensure optimum production for farmers, while conserving the forest-savanna ecosystem.