It’s WeedBuster Week (2 – 8 October 2011) and gardeners are encouraged to remove invasive alien plants, estimated to use 7% of South Africa’s water resources, and replace them with indigenous plants.
Alien plants have the ability to smother and destroy ecosystems. According to Leonie Joubert author of Invaded: The biological invasion of South Africa (Wits Press), invasive alien plants are estimated to use 7% of our water resources and have taken over 10 million hectares of land!
Invasive alien plants invade large stretches of tourist-friendly indigenous flora, create impenetrable, water-hungry thickets in water catchment areas, take over productive farming land, cause runaway fires, smother indigenous plants, reduce biodiversity and endanger ranching and livestock farming.
Cape Town was the first metropole in the country to develop a strategy and action plan for the management of invasive alien species known as the Early Detection and Rapid Response (EDRR) programme. Funded by the South African National Biodiversity Institute (SANBI), the EDRR programme involves successfully identifying and removing potentially problematic alien invader plant populations whist they are still relatively small and localised.
So far, the programme has identified 18 invader plant species. Included in the list are a number of garden species which are currently ‘jumping the garden fence’. They include:
- Pepper tree wattle (Acacia elata)
- Red flowering tea tree (Melaleuca hypericifilia)
- Australian cheesewood or sweet pittosporum (Pittosporum undulatum)
- Tree of heaven (Ailanthus altissima)
- Pampas grass (Cortaderia selloana),
- Spanish broom (Spartium junceum)
Supporting the integrity of South Africa’s natural resources through public employment programmes’ is this year’s theme for WeedBuster Week and up to 25 000 unemployed people have been employed to clear invase aliens plants under the direction of Working for Water (WFW), Natural Resources Management Programmes, Department of Environmental Affairs and are supported by various partners and stakeholders.
So what can you do?
- If you own or care for land, keep it clear of invasive alien plants (IAPs).
- Talk to neighbours that have IAPs on their property, so that your land is not invaded as a result of ‘seed pollution’ from IAPs on your neighbours’ land.
- Never accept a gift of an IAP from a friend and report the presence of an IAP in any garden centre to the South African Nursery Association.
- Never bring undocumented foreign plants or animals into our country (or take our plants and animals to other countries) as a tourist.
- Join a volunteer clearing (‘hacking’) group, and adopt a piece of land to keep it clear.
- Encourage your local authority, agricultural union, school, church, community bodies to learn about the monumental costs to society of removing invasive plants that have taken over local ecosystems.