In the vast arid stretches of Namaqualand, the remains of once thriving mines are eyesores. And the ongoing opencast mining operations for titanium and zirconium continue to remove thousands of tons of vegetation and topsoil.
But at a heavy metal strip mine operated by the Anglo American subsidiary, Namakwa Sands, a project is under way to prevent large tracts of land from remaining unusable in the wake of mining.
And it is a simple process, using local resources and involving local communities. Plants are dug up and replanted to secure the soil and value of the land. If the vegetation, which needs to be cleared ahead of strip mining, is preserved at the start of mining, the process of ‘revegetation by translocation†becomes even more straightforward.
‘If left unrehabilitated, the land is not useful for others, for example sheep farming or tourism. The real importance is to turn the natural capacity back to the country,†says Professor Suzanne Milton of the conservation ecology department at the University of Stellenbosch.
She heads the research project, which involves several postgraduate students in on-site learning near Lutzville in Namaqualand. This revegetation research is a key development to give effect to the National Environmental Management Act, which requires mines to rehabilitate disused mines and re-establish vegetation that will support pre-mining land use.
The translocation trials started in March 2001 with five indigenous species. Six hundred plants of each species — a total of 3 000 plants — were collected and transplanted to several 100m by 100m plots.
These measurements are indicators of the success in translocating plants and a particular species’ potential for revegetation.
About 1 200 plants were randomly selected to be monitored for survival, growth and ground cover.
The local communities were involved from the start — from digging up the plants to moving them. As part of this process, people are trained so that they will be able to sell their specialised skills to the mines for future translocations.
Milton says the challenge not just for the plants but also for the students who are running the project is to deal with the harsh weather conditions — sun, sand, wind and cold nights.
‘It’s physically extremely difficult to collect enough information,†she says. But the research has already produced results: the survival rate of the translocated plants is between 80% and 90% and insect species that used to live in the area before it was mined are returning.
This discovery has triggered specialised research. Postgraduate student Ndivhuwo Netshilaphala is now specialising in ant research. Worldwide, ants are used as indicators of environmental health: different species specialise in different food, therefore the more ant species in a particular area, the more resources there are.
Netshilaphala’s research has had another spin-off: the involvement of South Africa’s top ant expert, Dr Hamish Robertson, based at the Iziko Museum in Cape Town.
In addition, the project has triggered other research. The soil science department at the University of Stellenbosch has become involved in analysing soil samples collected on site. The reason? Mining disturbs soil composition, leading to, among other things, higher salt and magnesium levels. This affects the translocated plants.
Another spin-off has been the cooperation between Namakwa Sands mine, the research team and the University of Stellenbosch. Undergraduate students from the university are taken on one- or two-day trips to get first-hand experience of today’s conservation challenges. Many use this opportunity to conduct their own mini-research.
With the Namakwa Sands translocation research project producing these positive results, other applications are already being eyed. One of these is to use translocated plants to revegetate overgrazed ostrich farms in the Klein Karoo around Oudtshoorn in the Western Cape.