Are invasive aliens a real threat to biodiversity in South Africa?

Abstract

South Africa has abundant biodiversity, but also many invasive alien species, especially plants and fish, that can transform ecosystems. Invading alien trees and shrubs impact on fynbos and threaten up to a quarter of the nation's plant species. Freshwater ecosystems are often dominated by alien fish, while invasive alien plants invade the catchments of major rivers, riparian zones and open water surfaces. Invasieve alien pathogens and diseases, such as the rinderpest that decimated wildlife and wildstock at the end of the 19th century, pose a constant threat to biodiversity. Uncertainties in monitoring and predicting trends, and rehabilating priority conservations are important challenges.