Biological invasions in South Africa

Abstract

South Africa has played an outsize role in the history of biological invasions and the development of an invasion science to understand and mitigate their impacts. Containing a large region with temperate climate, South Africa, beginning with European colonisation in the seventeenth century, joined Australia, New Zealand, many oceanic islands, and large parts of the Americas as a victim of what historian Alfred Crosby termed “ecological imperialism, the biological expansion of Europe.” Besieged by terrestrial, freshwater, and marine species purposely or accidentally introduced, South Africans perhaps first perceived that such newly arrived species could be problematic in 1713 when smallpox arrived in Cape Town, killing many indigenous Khoikhoi, who attributed the introduction to the Dutch. European immigrants and their descendants, by and large, welcomed—indeed, deliberately introduced—many of the new additions to the biota, especially trees in the South African ecosystems lacking forests—savanna, grassland, and fynbos. Trees provided wood, fruit, and shelter and were an aesthetic amenity attractive to European settlers.