Are Mapungubwe's Elephants Eating Too Much?
26 October 2007
by Michele Hofmeyr
Elephants and their eating habits were up for discussion again, this time in the Mapungubwe National Park and World Heritage Site . Elephants are well-known for the damage they cause to trees by breaking off branches, stripping bark or even pushing them over. How to protect trees from this type of treatment was one of the main topics at a recent workshop convened by SANParks Scientific Services.
Several respected and influential scientists were in attendance to provide more insight in how to deal with such a complex issue. “The crux of the issue is that Mapungubwe was established as a cultural park and part of our mandate is to protect those aspects of the park that add to the “ambience” or “sense of place” explained Dr Rina Grant, Systems Ecologist from SANParks Scientific Services in Skukuza. “The most sensitive area in Mapungubwe is the gallery forest along the Limpopo River and this needs protection from repeated elephant impacts”. The Gallery Forest,, is also suffering the effects of water stress as irrigation farming and mining activities are reducing the river flow and the underground water table.
Fortunately there is valuable research being done to evaluate the establishment and growth of indigenous trees to restore the areas along the river where trees have died as a result of elephant impacts. This work is being done by Theo Scholtz from the School of Environmental Sciences and Development at the North West University. Elephants have opened up the under-story of the forest, which will increase the risk of fire. Trees are able to regenerate, but this requires water and specific habitats, both of which are limiting along the river banks.
However, research has shown that it is difficult to re-grow the forest trees once they are gone and of 2000 trees planted out during the experiment, only 18% survived and grew. Greater success was achieved with Acacia species, especially when young seedlings are planted below bigger more mature trees. These seem to have a “nursery” effect and afford the young trees more protection. Theo has shown that it is possible to rehabilitate damaged areas of the forest but it will take a long time and elephants will have to be excluded during the recovery time.
Although the decision to fence out elephants from certain sections of the sensitive forest areas had been taken by previous management, the group were able to discuss the aesthetics of such a fence and the best possible way to construct an effective barrier to keep elephants out. The first phase will involve putting up a 3.7km fence to close a gap between existing fences, and the proposed design is a 2 strand electric fence at heights of 1.3 and 1.5m. This type of fence has proved effective in keeping elephants out of the camps in Mapungubwe. “While the fence is up, we will use the opportunity to learn as much as possible about how the vegetation recovers and we will be monitoring various aspects of the gallery forest,” says Dr Grant.
Other conservation issues discussed during the workshop included the type of monitoring that is required throughout the park to ensure that biodiversity and ecosystems processes are adequately protected and more clearly understood. This included discussions on how to rehabilitate the important wetland areas of the park.
The workshop in Mapungubwe served to highlight the commitment of SANParks to conserve cultural, heritage and to acknowledge social and historical priorities while promoting sustainable biodiversity conservation and to include these aspects in plans for monitoring and management of the landscape.