A 90,000-year record of Afromontane forest responses to climate change.


Laboratoire d'Océanographie et du Climat, Expérimentation et Approche numérique/Institut Pierre-Simon Laplace (IPSL), Sorbonne Université-CNRS-IRD-Muséum National d'Histoire Naturelle (MNHN), 4 Place Jussieu, 75005, Paris, France. [Email]


Pollen records from African highlands are scarce; hence, the paleoecology of the Afromontane forest and its responses to glacial cycles are poorly known. Lake Bambili (Cameroon) provides a record of vegetation changes in the tropical mountains of Africa over the past 90,000 years, with high temporal resolution. Pollen data and biome reconstructions show a diverging response of forests to climate changes; the upper tree line was extremely unstable, shifting substantially in response to glacial-interglacial climate alternation, whereas the transition between the montane and lowland forests remained remarkably stable. Such ecological instability may have had a critical influence on species richness in the Afromontane forests.