Utilisation of invaders for secondary industries: a preliminary assessment

Invasive alien plants are invading some 125 million hectares in South Africa and Lesotho. More than R800 million has been invested in the clearing of invading alien plants in South Africa since October 1995. These clearing operations have had huge environmental, social and economic benefits but the benefits of the Working for Water Programme (WfW) have not yet been maximised. The initial treatment of a dense stand of invading alien plants could cost anything between R1,500 and R12,000 (on average R3,500) per hectare depending on the species and terrain factors involved. Investors have therefore had to ensure that maximum benefit is being derived from their investments. The environmental benefits of clearing operations include positive impacts on water resources, environmental stability and ecosystem function. The economic benefits include employment opportunities, value adding multipliers and economic empowerment of historically disadvantaged communities. By utilising biomass from clearing operations both the environmental and economic benefits of the programme are being enhanced. The environmental benefits include impacts on flood behaviour after clearing, dead biomass on fire intensity and its effects on soils and plant regeneration after fires, as well as the cost of fire management. The macro economic benefits of the secondary industry programme would include enhanced employment opportunities, increased government income through taxes, value-added multipliers, economic empowerment and training. Secondary industry projects in the Working for Water Programme have three primary objectives: 1. Maximising the positive economic impacts of the programme 2. Minimising dead plant biomass after clearing and 3. Minimising the net cost of clearing through the exploitation of biomass