Tackling invasive aliens

Invasive alien species pose one of the greatest threats to biodiversity in Cape Town. They compete with indigenous species for habitat, and in the case of vegetation, increase the intensity of fires and have a negative effect on water resources (both quantity and quality). According to the United States government, invasive alien species have effectively wiped out four percent of global GDP.
This is two and a half times Africa’s combined GDP.


After habitat destruction by humans, invasive aliens are the second biggest potential cause of species extinction in the world. Invading alien plants destroy the productive potential of land. Cape fynbos has a much lower biomass than woody invasive plants and consumes far less water. Invasive alien plants have a much higher combustible mass resulting in the intense fires that sweep across our city’s mountain slopes with frightening regularity.

Invasive aliens can burn with 10 times the heat of indigenous plants, destroying the fynbos seeds stored in the soil, or adapted for release in low-heat fires. Their own seeds survive, however, and as a result aliens usually sprout thicker than before on land that has recently burnt.

Invasive alien animal and plant-free city

The City is working towards a future invasive alien animal and plant-free city. In so doing it will work closely with other initiatives and organisations, such as the award-winning Working for Water Programme, led by the Department of Water Affairs and Forestry, as well as the Alien Vegetation Clearing Programme of the Table Mountain National Park.

Working for Water

Working for Water was launched in 1995 in an effort to tackle the problems of invading alien plants and unemployment. The programme has a focus on social development – primarily in job creation, of which 60% is reserved for women, 20% for youth and 2% for the disabled – but also conducts research, develops education and awareness campaigns, introducing stricter control measures at airports, ports and other border posts and devising a solid legal framework.

New regulations under the Department of Agriculture’s Conservation of Agricultural Resources Act have been promulgated to curb the influx of invasive alien species.

A crucial step is to educate people about the need to stop the spread of alien species. Through the Santam/Cape Argus Ukuvuka Operation Firestop Campaign that ran in Cape Town from 2000 to 2005 (a ‘brainchild’ of the Working for Water Programme), alien species were cleared from 78% of state land around the Table Mountain area. Only 21% of private land in this region has had alien species cleared.

Working for Water has a toll-free number (0800-005-376) to advise land owners and other concerned people on what to do.

It is illegal to litter, including throwing cigarettes out of the car. The by-law governing this will soon impose heavy fines for such actions, with the guilty person liable for any fire damage to property that may occur as a result.

source: SMART Living Handbook

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