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Research on invasion biology forms the pillar for SA’s efforts against invasives
Author: Media & Communication, Faculty of Science
Published: 08/06/2021

The research conducted by institutions such as the South African National Biodiversity Institute (SANBI) and the DSI/NRF Centre of Excellence for Invasion Biology (CIB) at Stellenbosch University forms the foundational pillar upon which South Africa's work against biological invasions are based.

At the launch of the second Biological Invasions Report recently, Minister of Forestry, Fisheries and the Environment (DFFE), Ms Barbara Creecy, said the status report “has created an excellent foundation on which to build a comprehensive monitoring and reporting programme, which can guide research and implementation efforts".

The report, titled “Status of Biological Invasions and their Management in South Africa", was launched during a media conference at the Kirstenbosch Botanical Gardens in Cape Town on 28 May 2021.

SANBI's acting chief executive officer, Ms Carmel Mbizvo, emphasized in her welcoming address that there are very few reports globally that give such a comprehensive coverage of the field of biological invasions at a national level.

The lead authors of the report, Dr Tsungai Zengeya and Prof John Wilson, both associated with SANBI and the CIB, thanked the 36 experts from 16 organisation who contributed their time and resources to compile and finalise the report. Click here to listen to their presentation about the main findings of the report.


Prof Dave Richardson, director of the Centre for Invasion Biology, says they work closely with SANBI and numerous other partners to address the key challenges associated with biological invasions in South Africa: “The CIB's contributions to the status report form a key part of our contribution to national policy. This includes, for example, reporting on the status of invasions as well as interventions to address invasions."

The report provides information on 1 880 species alien to South Africa (15% more species that the first report), about a third of which are invasive. Biological invasions are now regarded as the third largest threat to South Africa's biodiversity after cultivation and land degradation, and are responsible for 25% of all biodiversity loss.

Other significant findings are:

  • Current estimates suggest the ecological cost of invasive alien plants and animals to be more than R6.5 billion each year. This includes a decline in ecosystem services such as water and grazing, and in terms of agriculture – invasive pests.
  • Invasive trees use up 3-5% of South Africa's surface water runoff each year, a serious problem in an already water scarce country which is increasingly prone to drought. It has been calculated that Day Zero in Cape Town was brought forward by 60 days due to invasive trees sucking up water. The same impact occurs in other drought-stricken areas, such as the Eastern Cape.
  • Invasive trees increase the risk and intensity of veld fires, as it provides 15% more fuel to be burned in invaded areas. Consequently, fires burn at a higher temperature and containment measures are more difficult.
  • New alien species continue to arrive every year in South Africa, a notable example being the polyphagous shot hole borer beetle which has already killed thousands of trees in South Africa. The beetle and its associated fungus look set to be one of the most damaging and costly biological invasions faced by our country.

Click here to read the Minister Barbara Creecy's speech.

Click here to access the report: The Status of Biological Invasions and Their Management in South Africa.

​On the photo above, lead authors Dr Tsungai Zengeya and Prof John Wilson share the stage with Minister Barbara Creecy and the acting CEO of SANBI, Carmel Mbvizo, and Prof Dave Richardson, director of the Centre for Invasion Biology at Stellenbosch University. Photo: Wiida Basson