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

Pollen records from African highlands are scarce; hence, the paleoecologyof 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 biomereconstructions show a diverging response of forests to climate changes; the upper tree linewas extremely unstable, shifting substantially in response to glacial- interglacialclimate 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.