An ecological study of the plant communities in the proposed Highveld National Park, in the peri-urban area of Potchefstroom, South Africa

Abstract

The proposed Highveld National Park (HNP) is an area of high conservation value in South Africa, covering approximately 0.03% of the endangered Grassland Biome. The park is situated immediately adjacent to the town of Potchefstroom in the North-West Province. The objective of this study was to identify, classify, describe and map the plant communities in this park. Vegetation sampling was done by means of the Braun-Blanquet method and a total of 88 stratified random relevés were sampled. A numerical classification technique (TWINSPAN) was used and the results were refined by Braun-Blanquet procedures. The final results of the classification procedure were presented in the form of phytosociological tables and, thereafter, nine plant communities were described and mapped. A detrended correspondence analysis confirmed the presence of three structural vegetation units, namely woodland, shrubland and grassland. Differences in floristic composition in the three vegetation units were found to be influenced by environmental factors, such as surface rockiness and altitude. Incidences of harvesting trees for fuel, uncontrolled fires and overgrazing were found to have a significant effect on floristic and structural composition in the HNP. The ecological interpretation derived from this study can therefore be used as a tool for environmental planning and management of this grassland area.

Conservation implications: Grasslands are amongst the most threatened and least conserved vegetation biomes in South Africa, with less than 1.3% currently being conserved. The HNP has significant value for biodiversity conservation and the protection of this area will contribute to the preservation of the highly threatened Highveld vegetation types.