Patterns of diversity, endemism and distribution of bees (Insecta: Hymenoptera: Anthophila) in southern Africa

For southern Africa, patterns of bee diversity and endemism were studied with a special focus on South Africa and the Cape Floral Kingdom. Based on distribution records of 645 species incorporated in the “Southern African Bee Database” (SouthABees), the pattern of bee diversity was analysed on a 2° × 2° grid. The resulting map shows a bicentric pattern, with highest species diversity located in the arid west and in the relatively moist east. The investigation of distribution patterns of 516 South African species identified twelve distribution types that largely coincide with patterns in the seasonality of precipitation: winter rainfall, early to mid summer rainfall, late to very late summer rainfall and rain all year. The largest number of bee species is associated with the winter rainfall area (46.3% of the fauna) and with the early to mid summer rainfall area (36.5% of the fauna). Consequently South Africa is a centre of bee diversity of global significance. The most important centres of endemism are the winter rainfall area in the west (27.3% of total fauna endemic) and the early to mid summer rainfall area (29.1% of total fauna endemic) in the east. The relationship between bee/plant diversity patterns and speciation is discussed.