Biotic diversity in the Southern African winter-rainfall region

The outstanding diversity of biota of the Cape region is expressed differently in major groups: flowering plants and bees show high species richness in few clades combined with high endemism and remarkable functional adaptations; mammals and reptiles have a rich diversity of distinct intra-specific genetic lineages; and fresh-water fish are characterized by a high level of endemism but a low local species richness. Diversification has been promoted by the physical complexity of the Cape environment, as well as biotic interactions, such as those between bees and flowering plants. Endemism has been promoted by the uniqueness of local climate and soils, and, in the case of fishes, by the history of connections between the short Cape river systems. Maintenance of Cape biodiversity requires that key environmental factors that promote diversification are identified and retained.