Cape Town - Since the devastating fires in January 2000, Capetonians have been warned about the danger of invasive alien vegetation, especially for homes situated on the boundary of nature reserves.
Fires in pines, gums or wattle invasive species burn 10 times hotter and more intensively than cool fynbos fires. In the March 2015 fires, several homes surrounded by invasive plants were destroyed.
Given the scale of damage in the March fires, the City of Cape Town is urging property owners to take cognisance of invasive vegetation on their land.
The Alien and Invasive Species (AIS) regulations of the National Environmental Management Biodiversity Act, 2004 (NEMBA) came into effect in October 2014. The NEMBA AIS lists place invasive species in four categories.
“Property owners are encouraged to familiarise themselves with the invasive species lists and review the plants in their gardens to determine which plants are listed and then to take the necessary action,” said Louise Stafford, head of the City of Cape Town’s invasive species unit. “Non-complying landowners can receive a directive from the Department of Environmental Affairs compelling them to take the necessary action, so it is better to be pro-active and remove Category 1b plants and obtain a permit for Category 2 plants.”
2015 National Invasive Species Week
The inaugural National Invasive Species Week takes place from 10 to 17 October and celebrations will be held around the country.
Unlike National WeedBuster Week which historically highlights the 198 invasive alien plants, National Invasive Species Week recognises that the national list of invasive species includes both flora and fauna.
A total of 559 species is now listed as invasive. This includes: plants (383), mammals (41), birds (24), reptiles (35), amphibians (7), fresh-water fish (15), terrestrial invertebrates (23), fresh-water invertebrates (8), marine invertebrates (16) and microbial species (7).
The local National Invasive Species Week celebrations will take place on Tuesday, October 13, when the City of Cape Town launches the first in a host of Cape Town invasive species forums. The first meeting will take place in the Fish Hoek Community Hall at 9am.
Invasives in Cape Town
“In urban areas such as Cape Town, biodiversity faces various threats and invasive plants are globally regarded as the second biggest threat,” explained Stafford. “Invader plants compete with our indigenous fynbos for space and other resources such as water and light and in the absence of their natural enemies, out-compete fynbos to form monocultures of invasive stands.”
A number of fynbos species is today extinct as a result of invasive alien encroachment, with many more under species threat.
Target species are those invasives controlled by the City’s invasive species unit at no cost to the landowner. Property owners must remove non-target species.
Do you have any of these invasives on your property?
* Spanish broom (Spartium junceum), a poisonous plant native to the Mediterranean region. It spreads by seed dispersal, where it quickly competes with and replaces indigenous plants. Target species.
* Devil’s beard (Centranthus ruber), previously known as red valerian, is a Mediterranean native. It invades roadsides and urban spaces. Target species.
* Pampas grass (Cortaderia selloana) a vigorous South American grass that forms clumps and smothers other vegetation. Target species.
* Madeira vine (Anredera cordifolia) is a vigorous South America climber. Target species.
* Tree of Heaven (Ailanthus altissima) is a fast growing tree from China. Target species.
* Fountain grass (Pennisetum setaceum) is an ornamental grass from north Africa. It invades roadside areas and has the potential to spread to natural veld.
*l Green mother of millions (Bryophyllum proliferum) is a perennial poisonous succulent that outcompetes indigenous species.
* Cotoneaster (Cotoneaster franchetii), a native of south-west China, invades rocky outcrops, grassland and riverbanks.
* Australian myrtle (Leptospermum laevigatum) is an untidy, spreading shrub or small tree. It forms dense, impenetrable stands that outcompete and replace indigenous species.
* Periwinkle (V.major and V.minor) is a vigorous groundcover that can be particularly invasive. It is poisonous to livestock. Sterile cultivars or hybrids are not listed.
Stafford urges gardeners to replace invasive plants with appropriate indigenous plants or non-invasive exotics.
More information
For lists of invasive species, target species or to report sightings, visit www.capetowninvasives.org.za, www.invasives.org.za on how to remove invasives from your garden.
Kay Montgomery, Weekend Argus