Pleistocene refugia
The entire Cameroon line is considered a Pleistocene forest refuge for
its distinctive flora. Forest refugia are also supported because of the
high genetic diversity detected in different trees (Pineiro et al. 2017)
such as the genus Greenwayodendron (Migliore et al. 2018), and
other flowering plants. For example, Arabis alpina (L.) survived
the Pleistocene oscillations of temperature and drought in refugia. Once
the environmental conditions changed during the interglacial periods,A. alpina colonized or recolonized new sky islands in
East-Central Africa (Assefa et al. 2007).
It is possible that the populations of L. columnaris were
dynamically isolated and expanded within and between the sky islands of
West Central Africa. However, Pico Biao-Moka in South Bioko might be a
Pleistocene forest refuge to Afromontane plant species.