Abstract:
The aim of this study was twofold. Firstly the floristic composition, structure and environmental interactions of the vegetation types in the south-eastern Transvaal Highveld were investigated by using Braun- Blanquet procedures. Secondly the relative grazing capacity was determined for each of the land types in the study area. The study area covers approximately 140 000 hectares and extends from Middelburg to about three kilometers west of Belfast. The northern border is approximately twelve kilometres south of Stofberg. Most of the area is used for dry-land crop cultivation. The geology of the study area consists of the Sequence Karoo, Group Waterberg, Formation Loskop, Sequence Transvaal, Complex Bushveld and the intrusive rocks. The soils are heterogeneous and vary from clayey to sandy, due to the large variation in parent material. The Ba-, Ib-, Ea-, Bb-, Ad-, Ac-, and Be land types are represented in the study area. The study area was stratified according to land types and geology and a total number of 163 sample plots was placed in the stratified units. The vegetation was classified by using the PHYTOTAB-PC computer program. The results of the objective classification were refined by using Braun- Blanquet procedures. Phytososiological and synoptic tables were compiled and the results of both tables were discussed. The vegetation was classified into 28 plant communities which included 17 grassland, nine shrubland, one woodland and one forbland community. A community composition analysis classified the species of the different plant communities according to their competition status. DECORANA was used during the ordination of data. The ordination confirmed the classification of communities and was also used to interpret the enviromental factors characteristic of each plant community. Relative grazing capacity was determined for each of the land types by using the nearest plant, shoe point method. The identified plant communities together with relative grazing capacity can be used as a basis for vegetation management units as well as management recommedation in respect of grazing capacity in the Middelburg-Belfast region.
