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

Abstract

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