DOI: 10.36347/sajb.2021.v09i03.003

Pages: 68-83

From herbarium specimens and literature review of Rubiaceae, we established a list of 387 endemic taxa (species, subspecies and varieties) from Lower Guinea Domain, with 288 present in Cameroon. Two hundred and three taxa having specimens from BM, BR, BRLU, P, K, MO, SCA, WAG, and YA were taken into account in our analyses. The specific diversity was determined by counting the number of species per grid square with Arc view 3.3. The distribution maps are obtained by projecting the coordinates of collecting sites on map of Cameroon. It appears that there are several hotspots of Rubiaceae in Cameroun. Four principal zones are distinguished: Mount Cameroon area (86 taxa), Kupe and Bakossi area (66 taxa), Bipindi-Akom II area (68 taxa), and Yaounde and its surroundings (28 taxa). The most significant factor to explain the endemism and the specific richness of Rubiaceae in Cameroun is altitude. The high precipitation and the continental gradient also play an important role in explaining this richness. The confinement of endemic Rubiaceae in Atlantic forests seems to be an argument in favor of this hypothesis. The area around Yaoundé and the massifs around Bipindi have no conservation status. Both areas are under permanent threat from logging and slash-and-burn agriculture and from ever-increasing population pressures. There is an urgent need for conservation measures to be taken to protect these forests, the importance of which is highlighted in this study. Yaounde is a large urban agglomeration and the easily accessible hills could be, in the medium term, financially viable through ecotourism.