Deforestation and carbon stock in state forests in Côte d’Ivoire: The case of the Haut-Sassandra classified forest

This study assesses the impact of deforestation, primarily due to the expansion of cocoa plantations, on carbon stocks in the Haut-Sassandra Classified Forest (HSCF) in Côte d’Ivoire. The methodology was based on the processing of a 2019 Landsat image and a forest inventory in 117 plots of 625 m² each, respectively, to map land use in the HSCF and quantify biomass and sequestered carbon using allometric equations applied to dendrometric data. Supervised classification of the 2019 Landsat image showed that cocoa plantations occupy 80% of the landscape, while natural forest covers only 7%. This cocoa expansion in the HSCF is resulting in a massive reduction of both biomass and carbon stocks. Indeed, analyses indicate an average total biomass of 202.01 tonnes of dry matter per hectare (tDM /ha), with significant variations: forests and fallow lands store 480.74 and 411.55 tDM /ha, respectively, compared to only 23.55 tDM /ha for old cocoa plantations (>10 years). The total carbon sequestered in the HSCF is approximately 9 million tonnes. Its distribution is strongly influenced by land use type. Forest ecosystems exhibit the highest storage capacities, with an average of approximately 240 tonnes of carbon per hectare (tC /ha), while mature cocoa plantations sequester only about 11.77 tC /ha. The study concludes that forest conversion for agriculture results in a net loss of carbon, highlighting the urgent need to integrate the preservation of forest fragments and the promotion of tree fallows into national climate change mitigation strategies, such as REDD + initiatives.