South Africa’s Pathways of Introduction and Dispersal and How They Have Changed Over Time

Alien taxa have been introduced to South Africa through a wide variety of pathways, and have subsequently been intentionally or accidentally dispersed across the country. While many introductions to South Africa have been intentional, alien taxa have also been accidentally introduced, or have spread unaided into the country from neighbouring countries where they have previously been introduced. Similar to other regions, organisms of different types have been introduced to South Africa through different pathways, and some pathways have introduced more taxa that have become invasive than others. Changing socio-economic factors have played an important role in shaping the pathways of introduction and dispersal for South Africa. The first known introductions to South Africa were mostly intentional introductions from Africa for agriculture and medicine. However, as a result of increasing and geographically expanding trade and transport, the development of new technologies, and changing human interests and attitudes, over time, new pathways of introduction and dispersal developed, and the importance of existing pathways changed. Control measures have been put in place to manage some of the pathways, but despite these measures introductions continue to occur at an increasing rate. It is likely that these trends will persist into the future, and in particular, accidental introductions are likely to increase with increasing trade. Due to new legislation, the risks posed by legal intentional introductions should be reduced, but technological and political developments mean that it is becoming increasingly difficult to manage the pathways and enforce existing regulations. To better inform management, further research into the pathways of introduction and dispersal is required.