Abstract. Gnahore E, Douffi KG-C, N’guessan YJ, Amba AJG, Ibrahima D, Kone M, Bakayoko A. 2023. Floristic composition and structure of closed and open forests in the Banco National Park, Abidjan, Côte d’Ivoire. Asian J For 7: 17-26. Natural ecosystems are pressured to degradation caused by human activities. To develop conservation guidelines for these ecosystems, it was necessary to have enough information on their biodiversity. This study aimed to investigate the species richness, diversity, structure, and composition of vegetation in the Banco National Park (BNP), Abidjan, Côte d’Ivoire, in two forest types, namely closed and open forests. Vegetational data was collected using a sampling plot and itinerant methods. The results showed that 345 and 283 species were recorded in the closed and open forest, respectively, suggesting that the closed forest appears richer than the open forest. Fabaceae, Rubiaceae, and Apocynaceae were the most dominant families in both forest types. Both forest types had a high Shannon-Weaver diversity index and high Pielou equality index. The most important species in the open forest included Chrysophyllum subnudum Baker (Sapotaceae), Allanblackia floribunda Oliv. (Clusiaceae) and Funtumia africana (Benth.) Stapf (Apocynaceae), while in the closed forest were Strombosia pustulata Oliv. (Olacaceae), Turraeanthus africanus (Welw. ex C.DC.) Pellegr. (Meliaceae), and Monodora myristica (Gaertn.) Dunal (Annonaceae). The diametric structure showed the greatest proportion of individuals with low diameter classes, indicating regeneration potential. However, there were great differences in stand structure between the open and the closed forest, especially in high-diameter classes, indicating that the open forest has been pressured by timber cutting. The results of this study can serve as baseline information to develop conservation and rehabilitation strategies in BNP to sustain its biodiversity components.

La présente étude a été réalisée dans les forêts classées de Kimbrila et de Kanhasso au Nord-Ouest de la Côte d’Ivoire. Dans le cadre de cette étude, il s’agit d’établir une connaissance de la flore et la structure de la végétation de cette partie du septentrion de la Côte d’Ivoire. Pour ce faire, des inventaires de surface et itinérants ont été réalisés à travers les deux formations végétales. La richesse, la diversité et l’équitabilité des ligneux ont été évaluées. La structure de la végétation a été par ailleurs étudiée à travers la densité des ligneux, la surface terrière, la structure diamétrique et la structure verticale. Les résultats établissent un total de 127 et 104 espèces ont été recensées respectivement dans les forêts classées de Kimbrila et de Kanhasso. Les familles botaniques les plus représentées sont les Fabaceae et les Euphorbiaceae. Les valeurs des indices de Shannon indiquent une diversité moyenne des forêts classées de Kimbrila ((2,50 ± 0,10) et de Kanhasso (2,16 ± 0,90). La structure horizontale des tiges indique que la plupart des plantes ligneuses ont un diamètre inférieur à 60 cm. Toutefois, sur les 7 classes de diamètres considérées, les tiges de diamètre supérieur ou égal à 60 cm sont les plus nombreuses et représentent plus de 20 % des tiges comptabilisées. La densité des tiges est de 557,60 individus/ha à Kanhasso et 523,92 individus/ha à Kimbrila. La surface terrière des tiges, qui est de 11,653 m2/ha à Kanhasso et 12,488 m2/ha à Kimbrila, est contrastée par rapport à la densité. La végétation de ces forêts classées est structurée en 4 strates dont la composante arbustive est la plus dominante. Les sites d’étude sont bien évidemment des végétations de savane. This work was achieved in the Kimbrila and Kanhasso classified forests in North-West Côte d’Ivoire. The main objective of this study is to contribute to a better knowledge of the flora and structural these two classified forests in North-West Côte d’Ivoire. A botanical study based on plots and itinerant inventory conducted in these two forests. The richness, diversity and woody equitability were determined. The vegetation structure was study following the woody density, basal area, diameter class and the vertical structure. The results showed that there were 127 and 104 species recorded in the Kimbrila and Kanhasso classified forests respectively. Fabaceae and Euphorbiaceae were the most dominant families. In these two classified forests, the diversity high with a value of 2.50 ± 0.10 (Kimbrila classified forest) and 2.16 ± 0.90 (Kanhasso classified forest) corresponding to an average indice. The horizontal structure showed than more species richness found in all sample plots in the two classified forest types was present in the smallest diameter class (< 60 cm DBH). Species richness was classified into seven diameter (DBH) classes, while more than 20 % was recorded in the largest diameter class (> 60 cm DBH). The total number of trees per hectare (n/ha) of the Kanhasso and Kimbrila classified forests were 557.60 and 523.92. The basal area (11.653 m2/ha) of the Kanhasso classified forest was higher than that (12.488 m2/ha) of the Kimbrila classified forest. These classified forests vegetation were strutured in four states and domined by the woody species shrub. The study area were the savannah vegetation.