Vegetation classification of the proposed Heritage Park, North-West Province, South Africa

Abstract

The proposed Heritage Park will link Pilanesberg National Park and Madikwe Game Reserve with a corridor of approximately 170 000 ha, to form a conservation area of roughly 250 000 ha. This proposed Heritage Park will contribute to reaching the conservation target set for the Savanna biome. Developing a conservation area for eco-tourism will lead to job creation and it will increase the livelihoods of the people from the local communities. The escalating tourism demand at Pilanesberg and Madikwe, unique features, such as the Molatedi Dam, Marico River and Dwarsberg Mountains and the archaeological importance of the area further provides a strong motivation for the development of the proposed Heritage Park. For effective planning, development and management of the proposed Heritage Park, it is essential to have a sound knowledge base of the ecosystems present and its biota. Several sub-research projects have been planned, including a soil and vegetation survey (of which the current study forms a part), a land and biodiversity audit, a socio-economic impact assessment, a game carrying capacity survey, spatial planning, heritage status and development and traditional knowledge surveys. No vegetation studies have previously been carried out in the central part of the corridor area, which covers a surface area of more than 90 000 ha. The aims of this study were to classify and describe the vegetation of the Central Corridor Area (CCA), to map plant communities, to identify and describe broad vegetation units and to integrate this study with previous studies carried out in other parts of the proposed Heritage Park. Stratified, random sampling was done and 222 relevés were completed in the CCA. A total of 20 plant communities and 17 sub-communities were identified and described in four land types in the CCA, using the Braun-Blanquet approach. Data was processed using the TURBOVEG database and a visual editor for phytosociological tables, MEGATAB. The correlations between environmental variables and plant communities were identified with the use of Correspondence Analysis (CA) ordinations and Principal Component Analyses (PCA) ordinations in CANOCO. The plant communities and also the areas with serious bush thickening and old cultivated fields were mapped. The plant communities from different land types were combined into three vegetation units and four vegetation sub-units, which were described in terms of species composition and environmental variables and management recommendations were given. The first vegetation unit (the Acacia robusta – Acacia tortilis Vegetation Unit) was found on deep soil, on plains. The second vegetation unit (the Mundulea sericea – Vitex zeyheri Vegetation Unit) was also found on plains, but on shallow sandy soil. The third vegetation unit (the Grewia flavescens – Panicum maximum Vegetation Unit) was found on shallow, sandy and rocky soil on mountains. The vegetation classification of the CCA was also compared with the vegetation studies carried out in the Expansion Areas of Madikwe and Pilanesberg.