ABSTRACT
Mboandong is a small crater lake situated approximately 30 km to the north of Mount Cameroon. A core 13 m in length was collected from the lake centre in December 1981 with the objective of studying Holocene vegetation change in the lowlands of West Cameroon. Radiocarbon dating indicates that the base on the core is close to 7000 years old. Volcanic eruptions of Mount Cameroon between c. 7000 and 6000 years ago are indicated by ash deposits which are overlain by diatomite. Otherwise the lake sediments consist of fine-grained organic mud, with no obvious sedimentary breaks or any sign of the lake having dried out. A fairly rapid sedimentation rate of at least 1 m per 500 years is indicated. Predominantly forested conditions existed throughout much of the Holocene, possibly of the Congo type (everwet) rainforest prior to c. 2700 cal yr BP. At this time man was probably encouraging fruits of the ‘atili’ tree Canarium schweinfurthii as an oil-rich food. A major increase in Poaceae pollen after c. 2500 cal yr BP is most probably linked to a drying climate, as has now been inferred at numerous sites in tropical West Africa. An increase in pollen from regrowth and semi-deciduous trees possibly indicates a change to an Atlantic type (more seasonal) rainforest after this time. This climate change probably led to subsequent forest clearance, perhaps linked to the southwards migration of the Bantu people and spread of iron technology. Increased numbers of Elaeis guineensis pollen recorded after 1700 cal yr BP are indicative of cultivation. The oil palm appears to have replaced the atili tree as an oil-rich food source.
