Indigenous vs exotic plants

  • Indigenous: a term used to group plants that would naturally occur in a fairly large geographical area. A plant is indigenous to an area, if it would naturally be found there without man’s influence.
  • Exotics, are those plants that have been brought in from other places around the world, and very often require a lot of care for them to grow.
  • Aliens/invasives are plants that have usually been brought in as exotics, intentionally or unintentionally, but are so well adapted to their surroundings that they are able to spread uncontrollably. They have become naturalised meaning they are able to reproduce and spread without direct assistance of people. Alien invasive plants tend to push out, or out-compete, indigenous plants and consume precious resources at the same time.

Benefits of planting indigenous plants

  • they have specific characteristics that contribute to their success.
  • they are adapted to the regions soil, hydrology and climate
  • they have evolved specific characteristics that contribute to their success
  • they have evolved defences to many diseases and insect pests
  • they provide shelter and food for wildlife promoting biodiversity
  • they have socio-economic benefits

Water sucking plants

  • Many types of alien plants affect the quantity and quality of our surface water and groundwater, either directly or indirectly ( by causing soil erosion). These plants may be either  terrestrial or aquatic
  • The terrestrial ones affecting our water supply  the most are the poplars (Populus species), the wattles (Acacia species),  pines (Pinus species) and the eucalypts (Eucalyptus species)

Department of Environmental Affairs Alien and Invasive species regulations

  • The do’s and don’ts regarding invasive species are controlled by National Environmental Management Biodiversity Act (NEMBA), 2004 (Act No. 10 of 2004) under The Department of Environmental Affairs. The Alien and Invasive Species (AIS) Regulations became law on 1 October 2014. The AIS Regulations group invasive species into 4 different categories whereby invasive species must be managed, controlled or eradicated or are prohibited from being brought into South Africa. These regulations prevent invasive species from causing harm or further harm to
  • our fragile environment. Over 500 species of plants, animals, birds fish and reptiles are recorded in the National List of Invasive Species

Categories of alien invasive plants

Invasive species are divided into 4 categories:

  • Category 1 a: invasive species which must be controlled and eradicated. No form of trade or planting is allowed.
  • Category 1b: invasive species which must be controlled and wherever possible, removed and destroyed. No form of trade or planting is allowed
  • Category 2: invasive species, or those deemed to be potentially invasive, for which a permit is needed to carry out a restricted activity. This category includes commercially important species such as gum, wattle and pine trees.
  • Category 3: invasive species which may remain in certain areas or provinces. However, no further planting, propagation or trade  is allowed