Plant Assemblages along an Altitudinal Gradient of Mount Oku Forests (Cameroon)

Abstract

Plant assemblage organization along physical environmental gradients remains a central issue of community on local, regional or continental scales. Mount Oku, commonly known as Kilum-Ijim, situated at the North-west Cameroon has the most important remnant of Afro-montane forest in Central Africa. These forests are recognized as a globally important center of endemism and a hotspot for biodiversity conservation but they are now undergoing unprecedented degradation. The aim of this study is to identify different plant assemblages in Mount Oku forests. In order to explore variations in vegetation composition of the study area, we realized 102 floristic plots along an altitudinal gradient. The floristic plots were subjected to a hierarchical cluster analysis (HC) using the Ward method. Our results allowed us to reveal 9 plant assemblages on Mount Oku, situated at different altitudinal levels. At the landscape level, this forest cover is old, but the plant communities composing it are largely recent because they emerge from secondary dynamics following various disturbances of the inner forest (Crops, pastures, logging, etc.). These plant communities cover a large altitudinal range. However there are still communities of ancient forests but very disturbed, situated on altitudinal levels from about 1900 to 2600 m. The general composition of the forest flora of Mount Oku indicates that this vegetation has preserved characteristics of a tropical afromontane flora. The results show that the composition of plant communities is determined mainly by human activities that tend to erase the influence of natural factors such as altitude.