Classification and description of the vegetation in the Spitskop area in the proposed Highveld National Park, North West Province, South Africa

Abstract

The objective of the proposed Highveld National Park (HNP) is to conserve a considerable area of the poorly conserved Rocky Highveld Grassland and Dry Sandy Highveld Grassveld of the western Grassland Biome in South Africa. The park has not yet been proclaimed, but is currently under the management of the North West Parks and Tourism Board. The main aim of this study was to classify and describe the vegetation in the Spitskop area in the HNP. The areas affected by soil degradation were on the midslopes, footslopes, valley bottomland and the floodplains around the Spitskop hill. The concentrated grazing around the Spitskop area was also influenced by the existing dam in the floodplains. Floristic and soil degradation data were collected and used to classify and describe the plant communities of the Spitskop area. Vegetation sampling was performed by means of the Braun-Blanquet method and a total of twenty plots were sampled. A numerical classification technique (TWINSPAN) was applied to the floristic data to derive a first approximation of the main plant communities. Further refinement was achieved by Braun-Blanquet procedures. The final results of the classification procedure were presented in the form of a phytosociological table, with three major communities and three subcommunities being described. Canonical correspondence analysis was used to determine the direct correlation between plant communities and soil degradation types. Soil compaction and sheet erosion were found to be the most significant variables determining plant community composition. Rill and gully erosion were shown to be of lesser significance in explaining the variation in plant communities.

Conservation implications: Grasslands are amongst the most threatened biomes in South Africa, yet less than 1.3% are 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.