Vegetation dynamics, palaeoenvironments and climatic changes in the forests of western Cameroon during the last 28,000 years B.P.

Bantu expansion shows that habitat alters the route and pace of human dispersals

“…We used information on the latitudinal and longitudinal positions of the languages to reconstruct the probable ancestral geographical locations of each of the internal nodes of the trees in the posterior sample (Materials and Methods and SI Materials and Methods). We then used these reconstructions to record the routes of dispersal of Bantu speakers from their homeland, and we linked the reconstructed geographical position at each node to its inferred time, as recorded on the tree, and to information from palynological and paleoenvironmental studies (13)(14)(15)26) on the likely habitats at different times in the past.…”

“…or older for Bantoid, non-Bantu (58); (b) 4,000-5,000 B.P. for Narrow Bantu (13,14,16,44,59,60); (c) 3,000-3,500 B.P. for the Mbam-Bubi ancestor (61); and (d) 2,500 B.P.…”

“…Two major events in the recent paleoenvironmental history of Central Africa might have influenced the route of the Bantu expansion (10)(11)(12)(13)(14)(15)(16)(17)(18). The first was a contraction at ∼4,000 B.P.…”

Bio‐indicator species and Central African rain forest refuges in the Campo‐Ma'an area, Cameroon

“…Geological and palynological research of lake sediments from several sites has shown that 2500 BP the Central African forest experienced a catastrophic destruction that led to a major extension of the savannah (Maley & Brenac, 1998;Maley, 2002). Detailed pollen records from Lake Barombi Mbo in western Cameroon, lake Ossa in south Cameroon, Lake Kitinia in western Congo, Lakes Mboandong and Njupi in south Congo reveal the presence of pseudo-periods of about 2000-2500 BP for several tree taxa typical of mature undisturbed forest (Elenga et al, 1994(Elenga et al, , 1996Reynaud-Ferrera et al, 1996).…”

“…Detailed pollen records from Lake Barombi Mbo in western Cameroon, lake Ossa in south Cameroon, Lake Kitinia in western Congo, Lakes Mboandong and Njupi in south Congo reveal the presence of pseudo-periods of about 2000-2500 BP for several tree taxa typical of mature undisturbed forest (Elenga et al, 1994(Elenga et al, , 1996Reynaud-Ferrera et al, 1996). During this phase, the rainfall suddenly became more seasonal, reducing the moisture available for the vegetation, and therefore leading to a mass disappearance of mature forest tree species in several parts of Central Africa (Reynaud & Maley, 1994;Maley & Brenac, 1998;Maley, 1987Maley, , 2001). Reynaud and Maley (1994) argued that punctual climatic perturbations may have taken place in the 13th century followed by a phase with favourable climatic conditions from the 18th century onward that may have favoured the natural reforestation process that is being observed today.…”