Evaluation of selected restoration technologies in degraded areas of the Mokala National Park, South Africa

Abstract

Degradation is a global problem and does not only affect the livelihood of people but also the existence of fauna and flora. In Mokala National Park (MNP) extensive areas of high potential grazing land have been degraded and are in urgent need of restoration. The study was conducted in the Doornlaagte and Lilydale areas where degradation is severe and restoration needed. Degradation of soils in these eroded areas is the consequence of a loss of plant cover and density, mostly due to the overgrazing of sensitive areas before the MNP was established and because the area was used as a cattle farm. To prevent further degradation of the eroded areas, active restoration technologies were implemented. Active restoration is the implementation of techniques that involve the application of structures to improve the moisture and nutrients in the soil, re-seeding, brush packing (placement of woody twigs on degraded patches) and other methodologies to actively halt erosion and improve the ecosystem. If these techniques are successfully implemented it will hopefully contribute to species richness, diversity and soil vegetation cover. The active restoration technologies that were implemented at Doornlaagte and Lilydale include the brush packing technology, where branches of trees are packed on top of the degraded soil; ponding, where hollows are made in a half-moon shape in the soil to catch water and nutrients; and ponding & brush where the brush and ponding restoration technologies are combined. Some areas were left open where no restoration was applied. These served as control. The technologies were applied in April 2014 and were monitored the day they were implemented, with the second monitoring in October 2015 before the rainy season and the third monitoring at the end of February 2016. To achieve the mission of South African National Parks (SANParks) to develop, manage and promote a system of National Parks that represents biodiversity and heritage assets by applying best practice, environmental justice, benefit-sharing and sustainable use, persons from the Biodiversity and Social Projects (BSP’s) programme that work in MNP were used for the implementation of the restoration technologies and for monitoring. The BSP programme is supported by the Department of Environmental Affairs (DEA). ii Data were obtained from vegetation sampling at each technology and soil was collected to determine the soil seed bank and to analyse soil parameters. The Landscape Functional Analysis (LFA) monitoring technique was carried out to evaluate any change in the functionality at the study sites. Results show that although there were no significant differences, the density and richness of the vegetation did increase especially in the ponding & brush restoration technology at the Doornlaagte study site, whereas the ponding technology was the best technology at the Lilydale study site. The soil seed bank analysis shows that the most seed accumulated where the ponding & brush technology were applied in both the Doornlaagte and Lilydale study sites. The LFA methodology showed that there was an increase in the landscape functionality of both restoration study sites. The change was mostly observed after the first year of restoration, as the area experienced a severe drought which caused less changes to be observed in the second year of the study. Restoration is a long-term process and it is therefore recommended that this study be carried out over longer time periods.