The pathways of introduction of alien cactus species to South Africa
Ana Novoa-Centre for Invasion Biology, Stellenbosch University
Pathways, defined as a suite of processes that result in the introduction of alien species from one geographical location to another, are starting to be considered as a powerful instrument of alien species management and biosecurity.
In this study we examine the pathways of introduction of Cactaceae species (1846 species native to North and South America) into South Africa as an example.
Scientific papers and grey literature were scrutinised, expert knowledge was consulted and a survey of all businesses involved in the cactus trade in South Africa was performed.
Our results show that until the 20th century, the dominant pathways for cacti establishment in South Africa was deliberate planting done by farmers for economic reasons-for forage, fences or human consumption.
We found 70 nurseries as well as supermarkets, unofficial markets and small illegal retails involved in this trade. Despite this large commercial network, we found that all imports came from the same source.
Many cacti were sold under incorrect scientific names, making effective regulation of the ornamental cactus industry in South Africa impossible.