Bloemfontein Karroid Shrubland: distributed north of Bloemfontein

Abstract

• Four plant communities within the Bloemfontein Karroid Shrubland were identified. (81). • Supports SANBI’s update mapping of South Africa as described in the VEGMAP Handbook. (85). • Species composition and habitat preferences are documented. (60). • Possible plant communities found in Gh8 were identified and described. (71). • Plant communities were associated with terrain units found in Gh8. (68). Grasslands, the most widespread biome in the World, are vulnerable despite their high biodiversity and the various ecosystem services they provide. Threats include agriculture, mining, and urbanization. The Grasslands of South Africa, however, contain a unique vegetation unit resembling Karoo vegetation. Shallow soils on rocky outcrops, which create environmental conditions that expose plants to physiological drought in an otherwise high-rainfall area, result in the unique vegetation unit known as the Bloemfontein Karroid Shrubland. This vegetation unit, however, is poorly studied and is considered endemic to the Free State Province. Refined vegetation maps proposed by the late Professor Johann du Preez, further indicated that this vegetation unit might be more extensive than previously thought. With that in mind, most of the phytosociological studies conducted regarding this vegetation unit focused on the Bloemfontein area. The aim of this study was to investigate mapped and proposed sections of the Bloemfontein Karroid Shrubland in the vicinity of Brandfort and Verkeerdevlei. This will provide point data for the VegMap project of SANBI to refine the boundaries of the vegetation unit more precisely and wider than before. The Braun-Blanquet cover abundance scale was used to estimate vegetation cover in various plots. This data was captured in VegCap, imported into JUICE, where a modified TWINSPAN was performed. Classification was further refined using Braun-Blanquet procedures, which resulted in 4 communities and 10 sub-communities. Correspondence Analysis was performed on the data, making use of CANOCO and environmental variables fitted to the respective axes. Various important taxa that define this vegetation unit were present in the communities found during this study, which is an indication that both the mapped and proposed sections in the Brandfort and Verkeerdevlei areas can be regarded as part of the Bloemfontein Karroid Shrubland (Gh8).