The enigmatic tropical alpine flora on the African sky islands is young, disturbed, and unsaturated

Abstract

Significance Resilience is required to withstand or mitigate the effect of human-induced climate change. Today whole ecosystems are affected by climate change, but our understanding of their evolution and natural response is limited, often restricted to individual populations or species. The enigmatic flora on the tops of the African sky islands is isolated and unique, showing striking adaptations to the harsh tropical alpine conditions. Here we analyze genome data from a large fraction of afroalpine plants and show that this remarkable flora has a dynamic history with frequent colonizations and extinctions, most likely caused by previous natural climate changes during the ice-age cycles. The flora will be particularly vulnerable to human-induced climate warming, reducing alpine habitat into successively smaller areas.