Plant recovery on the 1922 and 1959 lava flows on Mount Cameroon, Cameroon

Plant surveys were undertaken in 1995 in the 1922 and 1959 lava flows in order to assess species richness on these lava flows on Mount Cameroon. A total of 128 species were recorded out of which 21 (16%) were only found on lava flow and nowhere else in other ecosystems in Cameroon; they could be considered as a contribution of the lava flows to the maintenance of overall species diversity of the mountain area. Also, apart from the lava flow area it is difficult to find in one area such a high diversity of ferns, orchids and even woody species such as Ficus species and Hymenodictyon biafra- num. The physiognomy of the recovering vegetation on lava flow is dominated at different stages of succession by different groups of plants, which also illustrates the successional pathway. The bare rock is first inhabited by lichens and mosses, followed by ferns, then herbs and climbers with stunted woody pioneers, and finally by immature woody pioneers. Comparison of observed data on species composition, basal area and density of plants on the 1922 lava flow and similar parameters in the intact nearby rainforest indicated that the turnover time on lava flow in the Mount Cameroon environment is at least 300 to 600 years.