Invasive Alien Plants

What is invasive alien vegetation? The Department of Environmental Affairs defines invasive alien plants as plant species that are exotic, non-indigenous or non-native to an ecosystem. Due to the lack of natural enemies and the resistance to local diseases, these plants tend to spread aggressively, which then threatens biodiversity, reduce water availability and increase the risk and intensity of wildfires.

Do we have a problem? Yes, even before the devastating June 2017 fires invasive alien vegetation such as Rooikrans and Black Wattle were allowed to grow unchecked on some properties. Although the fire destroyed most of the vegetation within the Conservancy, it also helped to disperse the seeds of these plants. Young plants sprouted very quickly and if these infestations are not checked, the problem will be worse than before.

What does the law say? According to the National Environmental Management Act 2004 (Act 10 of 2004), specifically Section 73, the landowner ‘must take steps to control and eradicate the listed invasive species.’ It also specifically states in Section 75(3) that ‘The methods employed to control and eradicate a listed invasive species must also be directed at the offspring, propagating material and re-growth of such invasive species in order to prevent such species from production of offspring, forming seed, regenerating or re-establishing itself in any manner.’

Download the full Act here.

Categories of invasive alien species: The ‘Alien and Invasive Species Regulations of 2014’  divides the invasive species into 4 categories

Category 1a: Must be ‘combatted or eradicated’.

Category 1b: Must be ‘controlled’.

Category 2: Requires a permit to be on a property. The species must not be allowed to spread outside the area defined in the permit. Most commercially grown alien plants such as the Blackwattle fall into this category.

Category 3: Subject to exemptions, but if it occurs in a riparian area, must be considered Category 1b.

Download the list of invasive species here.