One of the world's biodiversity hotspots, the Cape Floristic Region (CFR) in South Africa is characterized by remarkable vegetation with high levels of endemism and species richness. The floral diversity of the CFR is thought to be driven by relative climatic stability, but it is not homogenous across the whole region.
This study uses GBIF-mediated occurrences of nine classes of vascular and non-vascular plants to map the species richness of the CFR—highlighting the extreme diversity in the southwestern part of the region. Using high-resolution paleoclimatic data derived from stable isotope analysis of hyraceum samples (fossilized faeces and urine of the rock hyrax) up to ~20,000 years old, the authors explore the climate change dynamics in the western CFR.
The results of their analysis point to major transitions in mean climate state including series of abrupt changes in water availability of up 70 per cent—each lasting 500–2,000 years. The authors speculate that these changes may have driven a speciation pump, ultimately responsible for the high diversity in the western CFR today.