Using mammal excrement to explain the richness of the Cape Floristic region

Study explores regional climatic variation using high-resolution data derived from analyses of fossilized rock hyrax excrement samples

Data resources used via GBIF : 165,365,849 species occurrences
Rock hyrax
Rock hyrax—or cape dassie (Procavia capensis subsp. capensis) observed in Simon's Town, South Africa by Michele Bertoncini. Photo via iNaturalist (CC BY-NC 4.0).

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.

Original article

Chase BM, Boom A, Carr AS, Chevalier M, Quick LJ, Verboom GA and Reimer PJ (2019) Extreme hydroclimate response gradients within the western Cape Floristic region of South Africa since the Last Glacial Maximum. Quaternary Science Reviews. Elsevier BV 219: 297–307. Available at: https://doi.org/10.1016/j.quascirev.2019.07.006