Former Botanical Garden of ORSTOM (Côte d’Ivoire): What Remain after Thirty Years of Abandonment and Forest Restoration

Botanical gardens represent important places for ex situ conservation. One of these botanical gardens has been abandoned in Côte d’Ivoire for 30 years. This is the former botanical garden of ORSTOM. This study was conducted to determine the level of diversity of this former garden in order to assess the opportunity for its rehabilitation. The authors carried out inventories in 18 quadrats of 500 m2 through the vegetation to collect woody species. Dendrometric measurements (height, diameter) were also recorded to assess the structure of the site. A total of 190 species have been identified. They belong to 141 genera and 47 families. This former botanical garden contains important species because of their origin, status or particularity (threatened, endemic, rarity, etc.). A total of 19 threatened species including 2 endangered and west African endemic (Chrysophyllum azaguieanum J. Miège, Placodiscus pseudostipularis) were found at the site. Also, Chrysophyllum azaguieanum is declared extinct from Côte d’Ivoire. Four species are rare in the flora of Côte d’Ivoire: Balanites wilsoniana, Chrysophyllum azaguieanum, Gilletiodendron kisantuense and Loesenera kalantha. The most abundant species is Hopea odorata. Although this introduced species is considered globally vulnerable, it presents a risk of invasion in the forest of Côte d’Ivoire. The diameter and height structures show that all the stages of development are presented indicating a good regeneration on the site. Ultimately, this botanical garden deserves to be rehabilitated and especially urgent management of Hopea odorata is needed to prevent an invasion of this species.