Impacts of Cocoa Farm Establishment on Original Vegetation Formations in Western Côte d'Ivoire: The Case of the Bakouma Department Landscape

The mountainous relief of the western region of Côte d’Ivoire, combined with the presence of extensive savannas adjacent to forest areas, did not originally make this part of the country a prime zone for cocoa production. The objective of this study is to assess the impact of cocoa farm establishment on the original vegetation formations within the landscapes of Western Côte d’Ivoire, using the Biankouma Department as a case study. To achieve this, the methodology first consisted of a series of digital processing operations applied to a satellite image from the Landsat sensor covering the study area, in order to produce a land use map. Subsequently, direct field observations coupled with botanical inventories were conducted to determine the floristic diversity within cocoa plantations. Results reveal that in 2018, the Biankouma landscape was mainly composed of savanna and cocoa plantation classes, occupying respectively 35% (169,260 ha) and 30.3% (146,640 ha) of the total area. Floristic inventory data indicate a loss of species associated with the conversion of forest areas into cocoa plantations. Forests contained 141 species compared to only 51 species recorded in cocoa plantations established on former forest lands. Conversely, for shading young cocoa plants, a higher number of species was observed in plantations established on former savanna lands (129 species) than in natural savannas (98 species).