The Cape Peninsula, South Africa: Physiographical, biological and historical background to an extraordinary hot-spot of biodiversity

The Cape Peninsula, a 470 km(2) area of rugged scenery and varied climate, is located at the southwestern tip of the Cape Floristic Region, South Africa. The Peninsula is home to 2285 plant species and is a globally important hot-spot of biodiversity for higher plants and invertebrates. This paper provides a broad overview of the physiography, biological attributes and history of human occupation of the Peninsula. The Peninsula is characterized physiographically by extremely high topographical heterogeneity, very long and steep gradients in annual rainfall, and a great diversity of nutrient-poor soils. Thus, the Peninsula supports a high number of habitats and ecological communities. The predominant vegetation is fynbos, a fire-prone shrubland, and 12 broadly characterized fynbos types have been described on the Peninsula. Animal community structure, especially with regard to invertebrates, is poorly known. Vertebrate community structure is probably strongly influenced by nutrient poverty and recurrent fire. Generally, most vertebrates are small and typically occur in low numbers. Some invertebrates play keystone roles in facilitating ecological processes. Human occupation of the Peninsula was limited, until relatively recently, by nutrient poverty. After Dutch colonization in 1652, direct and indirect impacts on the natural ecosystems of the Peninsula escalated dramatically, and by 1994, some 65% of original natural habitat was either transformed by urbanization and agriculture, or invaded by alien plants. Nonetheless, there is still excellent potential to conserve the Cape Peninsula's remaining biodiversity.