Introducing ... the Phalaborwa Land-Use Laboratory

Mightyman Mashele of the SAEON Ndlovu Node points to some elephants browsing on a mine dump. The extensive operational area of the Palabora Mining Company’s copper mine, which includes the second largest hole in the Southern Hemisphere, extends beyond the background. (Picture: Tony Swemmer) Cattle graze on the floodplain of the Selati River. The floodplains provide a key resource of green grass through the dry winters, which helps to sustain extremely high densities of domestic livestock in the communal rangelands to the west of Phalaborwa. (Picture: Tony Swemmer) Syenite koppies and undisturbed Mopaneveld contrast sharply with the man-made mine dumps in the background. The natural koppies support a remarkably high diversity of trees and reptiles. (Picture: Tony Swemmer) A herd of elephants is captured by a SAEON camera trap as they explore a rock dump on the grounds of the Palabora Mining Company. (Picture: Tony Swemmer)

It is often assumed that the transformation of land for economic development destroys all the biodiversity of the area where it occurs. Yet this is only true for extreme cases such as dense urban development.

Many developments result in only partial losses of biodiversity, creating modified ecosystems that, although very different in appearance to the original natural systems, still deliver important ecosystem services. Examples include communal rangelands, small-scale cultivation, game farms and rehabilitated mine dumps.

But exactly how much biodiversity is retained in such land uses? How stable are these modified ecosystems and the ecosystem services they provide? Is it likely that these ecosystem services will persist in the long term, particularly in the face of global climate change?

Based in Phalaborwa, the SAEON Ndlovu Node is well positioned to tackle these questions, as Phalaborwa is surrounded by a variety of land uses (Figure 1). These include the urban environment of the town itself, a major mining complex, extensive rural lands, including communal rangelands and areas of small-scale cultivation, as well as commercial game farms, all within a 20km radius of the Ndlovu Node offices. These represent almost all the major land-use transformations found in the savanna biome of South Africa.

The Kruger National Park and many private nature reserves alongside provide benchmark sites for comparing how biodiversity and ecosystem services change over time, in both natural and modified systems. As an added bonus the area contains freshwater ecosystems (the Olifants and Selati rivers) and syenite koppies within the dominant land uses, both of which support unusually high levels of biodiversity.

Studying the effects of land use and climate change

The Phalaborwa area therefore provides an ideal location to study the effects of land use and climate change on biodiversity and ecosystem services, and with funding from the Palabora Mining Company (PMC), the SAEON Ndlovu Node has embarked on a long-term project to do just that.

Over the past two years, the Node has been conducting biodiversity surveys for PMC, whose properties include not only operational mining areas, but also rehabilitating rock dumps and tailings dams, two game reserves and communal rangelands. The influence of the neighbouring Kruger National Park on the rehabilitation of the mining areas has been particularly intriguing here, as a variety of wildlife has colonised these areas. One focus of research is to determine if the presence of large herbivores can stimulate the rehabilitation process.

New SAEON-funded projects are adding to the PMC surveys to expand the scope of the work to other land uses and relevant ecosystem services.

Work to date includes a study of the effect of rural rangelands on plant diversity, conducted by the South African National Biodiversity Institute (SANBI) with support from SAEON, as well as a comparison of bird diversity in Phalaborwa town, the Kruger National Park and communal rangelands conducted by Bernard Coetzee, a PhD student at Stellenbosch University.

Last year, a study of dung beetle diversity in the Kruger National Park, the mining area, communal rangelands and a game farm was conducted by the Scarab Unit of the University of Pretoria, with funding from SAEON and PMC. The same support enabled surveys of reptile, amphibian and small mammal diversity in the mining complex and a neighbouring game reserve. The report of the reptile and amphibian survey is available here. 

Ndlovu Node staff began conducting annual surveys of riverine birds along the Selati and Olifants rivers last year. In addition, they are using an array of camera-traps, funded by PMC, to compare large mammal activity in the mining complex and the Kruger National Park. They are also completing a survey of the tree diversity on the syenite koppies within the Kruger National Park, the mining area, and communal rangelands. Five students from the University of the North-West will begin various surveys of plant diversity on the rehabilitation areas of the PMC mining areas this month.

Finally, the Node has recently entered into an agreement with South African National Parks (SANParks) to employ seven environmental monitors, funded by the Department of Environmental Affairs. Two of these monitors will be deployed in the Phalaborwa area to collect data on the state of biodiversity and ecosystem services in the communal rangelands.

Figure 1. The various land uses in the Phalaborwa area.