Invasive Alien Plants (IAPs) are frequently considered as a main threat to biodiversity and economic development. IAPs are described as species which are ‘non-indigenous’ to an area and which have been introduced from other countries either intentionally (for domestic or commercial use) or accidentally; furthermore, they have the ability to reproduce and spread without the direct assistance of people into natural or semi-natural habitats and are destructive to biodiversity and human interests (WESSA-KZN, 2008). IAPs cost South Africans hundreds of millions of rand annually in resources spent on management and lost agricultural productivity. Many IAPs are products of unwise and unintentional plant introductions. SANBI’s Invasive Species Programme, formerly Early Detection and Rapid Response programme, (funded by Working for Water programme, Natural Resources Management branch – DEA) was formed to control and manage emerging invasive alien plants in South Africa.
Notice 3 of the National Environmental Management: Biodiversity Act 2004 (Act No, 10 of 2004) lists 379 plant species that are legally declared invasive species. Each species is assigned to one of three categories based on the level of threat posed by the species and the legal status assigned to each:
Invasive species requiring compulsory control. Any specimens of Category 1a listed species need, by law, to be controlled and maintained. No permits required for having in possession or to exercise control over the species. No permit will be issued for restricted activities.
Invasive species that are compulsory to contain the specimen, keeping it from spreading, if a Invasive Species Management Programme has been developed, a landowner must control it in accordance with it. No permits required for having in possession or to exercise control over the species. No permit will be issued for restricted activities.
Invasive species requiring a permit to carry out restricted activities and is regulated by activities. A permit is required to import, possess, grow, breed, move/ relocate, sell, buy, or accept as a gift of any plants listed as Category 2 plants. No permits will be issued for Category 2 plants to exist in outside of the specified land as indicated in the permit and will be treated as Category 1b.
Invasive species regulated by are or occurrence. Specimens are subject to exemptions and prohibitions. Species found in riparian areas will be considered Category 1b Listed Species. No permits required for having in possession or to exercise control over the species. No permit will be issued for restricted activities.
There are numerous ways to control the growth and spread of alien invasive plants. The ‘treatment’ would depend on the species being controlled. Invasive Species and must be managed according to regulation 3 of NEM:BA, 2014
Several alien plants have natural enemies, such as insects and diseases that only affect a specific species. The controlling agents (beetles, viruses) are sourced from the country of origin and released here among an invasive species to control it.
Young or small invaders can be manually removed from the soil. The plants should be stacked and disposed of responsibly to prevent regrowth.
Larger plants and trees can be chopped or cut down. Trees can also be killed by removing a 30 cm – 40 cm strip of bark around their trunks (known as ‘ring-barking’). This prevents food going to the leaves and kills the tree.
Two or more chemical methods can be used at the same time for example ring-barking and then spraying herbicides on the stump.
The task of managing alien vegetation lies mainly with landowners. In 18 September 2020, the Minister of Environmental Affairs published the Alien and Invasive Species lists in terms of sections 66(1), 67(1), 70(1)(a), 71(3) and 71A of the National Environmental Management: Biodiversity Act, 2004 (Act No. 10 of 2004). The regulations call on landowners and sellers of land to assist the Department of Environmental Affairs to conserve our indigenous fauna and to foster sustainable use of our land.
It is important to know that non adherence can result in a criminal offence punishable by a fine of up to five million rand (ten million if a second offense) and or a period of imprisonment of up to ten years.
ENVASS has a holistic approach to all matters pertaining to the environment and consequently, we ensure that every aspect impacting on the environment is taken into account. As part of our scientific approach to alien invasive species identification, mapping, control, and eradication – we include a biodiversity assessment on indigenous vegetation. Our clients are not charged extra for this as it can be done simultaneously with alien invasive surveying. Biodiversity assessments are important as part of an alien invasive management plan due to the threat posed by aliens to biodiversity. By knowing how species-diverse a particular site is, one can determine the significance of the threat by aliens and act accordingly.