New data on the history of the plateau forest of Okomu, southern Nigeria: an insight into how human disturbance has shaped the African rain forest

The classic 1955 and 1956 papers by Eustace Jones describe vegetation patte rn, process and history in Okomu Forest, south-western Nigeria. Jones and c olleagues were puzzled to find an extensive layer of charcoal and pottery b elow mature mahogany forests. Based on an extensive review of historical do cuments and the estimated ages of dying emergent tree species, Jones sugges ted that the forest in Okomu had regenerated after a human population decli ne 200-300 years previously. We made radiocarbon measurements on samples fr om the layer of charcoal and pottery described by Jones. In addition, we ob tained delta(13)C measures from a soil profile cutting through the charcoal layer. The charcoal dates to about 700-750 years BP whilst the delta(13)C profile showed no evidence of input of organic matter from C-4 grasses. The se results are discussed in the light of other recent archaeological eviden ce of the impact of humans on the rain forests of Africa during the last 20 00-3000 years. It seems that extensive archaeological remains are hidden be neath much of the African rain forest, suggesting that human disturbance ha s been one of the dominant factors affecting forest structure and compositi on in recent millennia.