title: Why do tropical mountains support exceptionally high biodiversity? The Eastern Arc mountains and the drivers of Saintpaulia diversity.
abstract: We combine information about the evolutionary history and distributional patterns of the genus Saintpaulia H. Wendl. (Gesneriaceae; 'African violets') to elucidate the factors and processes behind the accumulation of species in tropical montane areas of high biodiversity concentration. We find that high levels of biodiversity in the Eastern Arc Mountains are the result of pre-Quaternary speciation processes and environmental stability. Our results support the hypothesis that climatically stable mountaintops may have acted as climatic refugia for lowland lineages during the Pleistocene by preventing extinctions. In addition, we found evidence for the existence of lowland micro-refugia during the Pleistocene, which may explain the high species diversity of East African coastal forests. We discuss the conservation implications of the results in the context of future climate change.
authors.affiliation: Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, Zoological Museum, University of Copenhagen, Copenhagen, Denmark. dimitard.gwu@gmail.com
authors.forename: Dimitar
authors.initials: D
authors.lastname: Dimitrov
authors.forename: David
authors.initials: D
authors.lastname: Nogués-Bravo
authors.forename: Nikolaj
authors.initials: N
authors.lastname: Scharff
mesh_terms: D000465:Algorithms; D019540:Area Under Curve; D044822:Biodiversity; D006239:Haplotypes; D007630:Kenya; D019684:Magnoliopsida / Q000502:physiology*; D010802:Phylogeny; D058974:Phylogeography; D013045:Species Specificity; D013636:Tanzania; D014329:Tropical Climate