War on Aliens

Jan 6, 2016 | Project News


Problems arising from the management of biological invasions can be either tame (with simple or obvious solutions) or wicked, where difficulty in appropriately defining the problem can make complete solutions impossible to find.

Four case studies focussing on the prevention, eradication and impact reduction of biological invasions are reviewed, assessing the drivers and extent of wickedness in each.

The results show that there is a disconnect between the perception and reality of how wicked a problem is and that this could influence the likelihood of successful management.


Invasive alien plants are one of the greatest threats to water security and are the cause for significant destruction of natural habitat in the region.  Their removal, with follow-up rehabilitation of the natural environment, offers considerable employment potential for local people. Various products from the biomass (expanded upon below) can provide income for rural communities. The Gouritz Cluster Biosphere Reserve will identify and implement innovative projects that make productive use of invasive alien plants, simultaneously removing a dangerous threat to aquatic ecosystems and providing valuable work opportunities for local communities.

Working for Water, Working for Wetlands, Working for Woodlands and Working on Fire are major government-sponsored initiatives to eradicate invasive alien vegetation, facilitate and co-ordinate integrated fire management and promote and assist with the restoration of important wetland areas, while at the same time addressing unemployment among unskilled people. By building, strengthening and adding value to partnerships, for example, linking farmers and other land owners to these multi-million Rand public-funded projects, the proposed biosphere reserve will function as a catalyst, promoting employment and business opportunities and improving the state of water resources. Potential projects include:

  • utilising biomass from invasive alien plants for production of electricity, using, for example, turbines;
  • “compots” – living pots, made from alien plant biomass, for nurseries and carbon sequestration projects;
  • Carbon sequestration projects on degraded agricultural land;
  • Charcoal production and sales, firewood.


Several alien invertebrates are threatening the biodiversity of the Gouritz domain. Foreign invertebrates are attacking indigenous bees and the Argentine ant poses a serious threat to fynbos biodiversity as they prevent seed dispersal of many endemic plant species. Alien fish are a major threat to indigenous species in the rivers, and to river functioning in general. Problem species include bass, bluegill sunfish, trout, and the Mozambique Tilapia. Considering the high levels of endemism of freshwater fish in the Cape fold mountains, alien fish are considered as a serious threat.

Acacia pycnantha, the golden wattle, competes with and replaces indigenous species (Photo: AnneLise Vlok)  

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