Evaluation of restoration and management actions in the Molopo savanna of South Africa : an integrative perspective
Harmse, Christiaan Johannes
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The loss of ecosystem resilience and range-land (often referred to as veld in South Africa) productivity is a major problem in the semi-arid Savanna environments of southern Africa. The over-utilization of range-lands in the Molopo region of the North-West Province in South Africa has resulted in profound habitat transformations. A common regional indicator of range-land degradation is the imbalance in the grass-woody ratio, characterized by a loss of grass cover and density with increased shrub or tree density. This can result in major reductions of range-land productivity for the grazing animal, forcing land users to apply active or passive restoration actions to improve range-land condition, control the thickening of woody species (bush thickening), mitigate economic losses and restoring the aesthetical value of the Savanna environment for ecotourism and game hunting aspects. This study formed part of the multinational EU-funded PRACTICE project (“Prevention and restoration actions to combat desertification: an integrated assessment”). The first aim of the study was to evaluate locally applied restoration actions using a participatory approach, followed by interviews with certain stakeholders that formed part of a multi-stakeholder platform (MSP) related to the livestock and game farming community in the Molopo. Participants of the MSP ranked indicators according to their relative importance regarding the restoration actions on an individual basis. The individual ranking results were combined with quantitative bio-physical and qualitative socio-economic measurements for each indicator in a multi-criteria decision analysis (MCDA), whereby the alternative actions were ranked according to their relevancy and performance. The results were then shared with members of the MSP in order to stimulate discussion among the members and contribute to the social learning of the project outcome. The overall positive response and acceptance of results by members of the MSP changed the perceptions and objectives of the land users regarding range-land management. This type of participatory assessment was therefore found to be very promising in helping to identify more sustainable actions to mitigate range-land degradation in the Molopo Savanna region. There is, however, still an urgent need to create legal policy frameworks and institution-building, to support local-level implementation in all socio-ecological and economic settings, particularly in communal areas. The second aim was to evaluate the effect of two chemical bush control actions (chemical hand- (HC) and aeroplane control (AC)) as well as rotational grazing (RGM) on the Molopo Savanna vegetation. Results show that range-land productivity, i.e. forage production and grazing capacity, was found to be negatively related to the woody phyto-mass in the savanna system studied. Bush thickening influenced grass species composition which was commonly associated with a decline in the abundance of sub-climax to climax grasses, respectively. All three actions (HC, AC & RGM) significantly reduced the woody phytomass and increased forage production and grazing capacity. Although AC resulted in the highest reduction of woody phytomass, the highest forage production and grazing capacity was found under RGM. The second highest grazing capacity was found in HC sites, which was due to a high abundance of perennial, palatable climax grass species. Results from this study also show that the patterns and compositions of grass species, grass functional groups (GFGs) and woody densities indicated by RGM and chemical HC, best resemble a productive and stable savanna system that provides important key resources to support both grazing and browsing herbivores.