Invasive plants and animals pose a threat to the biodiversity of the Rivers of Hout Bay and cost millions of Rands to remove. Invasive plant species take too much water from our rivers and out compete endemic species. It is important to know which species are invasive and to assist the Invasive Species Unit in the removal thereof.
Invasive species may generally be recognized as such because they grow so prolifically. Some species may not be listed as invasive, but be an invader in the Hout Bay River system. If you are not sure whether a species is an invader, please first look at http://www.invasives.org.za/ and contact FORHB before embarking on a removal exercise.
Below is a list Invasive Plant Species to be removed from the Rivers of Hout Bay. Note, this list is not complete, please contact us should there be invasive species that need to be added to the FORHB list.
- Acacia Salinga (Port Jackson Willow)
- Ageratina (Eupatorium) adenophora
- Acacia melanoxylon (Australian Blackwood)
- Cortaderia selloana (Pampas grass)
- Canna indica (Canna)
- Centranthus ruber (Devil’s Beard previously Red Valerian)
- Echium vulgare (Blue Echium)
- Eriobotrya japonica (Loquat)
- Eucalyptus spp.
- Eugenia (Brush cherry)
- Ipomoea purpurea (common morning glory)
- Lantana camara (Lantana)
- Melia azedarach (Syringe)
- Nasturtium officinale (Watercress)
- Nerium oleander (Oleander)
- Pennisetum clandestinum (Kikuyu)
- Paraserianthes lophantha (Albizia/Stinkbean)
- Pinus spp.
- Populus Albus (White poplar)
- Solanum Mauritiainum (Bug weed)
- Spartium Junceum (Spanish Broom)
- Tribulus Terrestris (Devil Thorns)
- Tradescantia zebrine (Wandering Jew)
- Vinca (Periwinkle)
Palmiet holds the banks in tact in flood conditions The palmiet in the foreground needs to be encourages, but the succulent on the right is invasive and spreading down the river.
Tips for landowners and project leaders taking on invasive species clearing projects on Hout Bay rivers:
Once you have removed invasive species, check and re-weed at regular intervals. Use a course mulch to stabilise soils in areas where erosion is a concern. Residents living on river fringes may want to use water wise barrier plants for planting on the perimeters of their properties for security purposes, but choose non-invasive species.
“If you are planting a rough guide to the numbers of plants used per square metre of planting area is to work with an average of four plants per square metre planted. This allows two to six plants per square metre as follows: Where a large shrub (e.g. Rhus or Chrysanthemoides) is planted then only plant one or two other small shrubs (e.g. Helichrysum cymosum or Pelargonium capitatum) in that square metre. Where small plants (e.g. Cyperaceae, ground covers, H. cymosum, etc) are planted as a dense planting then estimate an average of four to six plants per square metre planted depending on the size of the individual plants (these could be tiny and there may be planting losses).”
Lee Jones – Indigenous Vegetation Consultancy
The new National Environmental Management: Biodiversity Act (NEMBA) – Alien & Invasive Species Regulations – was gazetted on 1 August 2014.
The National Invasive Species List comprises more than 550 invasive species in 4 categories which have to be either eradicated or brought under control, as they displace indigenous flora and fauna, in the process destroying delicately balanced eco-systems.
This destruction has a direct impact on our land and water resources.
How does the new legislation affect us in Hout Bay?
Municipalities: All municipalities and large landowners must, by law, develop an Invasive Species Management Plan within 3 years of the NEMBA law being promulgated (1 August 2014).
Said plan has to be implemented by all property owners.
Identified invasive species www.invasives.org.za. are regarded as a liability and must be identified before the sale of any property.
The NEMBA Regulations state that a seller of property must, prior to the relevant sale agreement, notify the purchaser of the property in writing, of the presence of listed invasive species on that property. A copy of a seller’s Declaration of Invasive Species must be lodged with The Compliance Officer, Biosecurity Services, Department of Environmental Affairs.
Estate agents will not be able to sell a property without completing a ‘Declaration of Invasive Species’ certificate.
Permits will be required for all category 2 plants listed as invasive but which have a commercial use; i.e. pines and eucalyptus.
Category 2 lists 118 species that will require permits.
Employment opportunities: Horticultural and fauna experts can sign up to become invasive species consultants capable of identifying invasive species on a property and signing off on a ‘Declaration of Invasive Species’ certificate.
If you would like to know more please refer to www.invasives.org.za.