New thinking needed on clearing invasive aliens
A sea change is needed when dealing with invasive alien plants. According to Brian van Wilgen of the Council for Scientific and Industrial Research (CSIR) at the annual Fynbos Forum, the problem of invasive aliens is being addressed without proper planning and monitoring, and as a result, money is being wasted.
Delegates at the Forum, held in Cape St. Francis between 16 and 19 July, heard that more than 1.8-million hectares of land in South Africa is densely covered by invasive alien plants. A further 20-million hectares is invaded. Researchers projected that it would cost more than R35-billion to control the existing biomass in the country.
Van Wilgen said that invasive aliens plants are spreading by around 10 percent per year. That’s double the official growth rates quoted by government’s Working for Water programme, which estimates growth of five percent a year. “These alien plants are spreading much faster than we thought. Fynbos is set to disappear, mainly under pines.” He said invasive alien plants are being cleared without the necessary planning, and without clear time-based goals. More funding also needs to go into monitoring alien-clearing activities, including the costs involved in clearing.
Van Wilgen also said the biological control of aliens required further focus. Three percent of Working for Water’s total budget was spent on bio-control methods in the past year. He said that could be doubled. Working for Water’s total budget for 2012/13 is R850-million.
Debbie Sharp, of the Department of Environmental Affairs’ Natural Resource Programmes said 28 bio-control agents had been released on 26 invasive alien plants in the fynbos biome between 2003 and 2012. In total, there have been more than 6000 releases completed over the past decade. Around three quarters of bio-control species have proven successful, but around a quarter had failed.
According to Christo Marais, Head: Operations, Natural Resource Management Programmes of the Department of Environmental Affairs, eradicating invasive alien plants and the additional value-added industries offer good job opportunities. In the Western Cape alone, some 7.5-million tonnes of harvestable biomass is available for use in industries such as furniture-making. Across the country, 84-million tonnes of harvestable biomass can be used.