Phytosociology of the Ba and Ib land types in the Pretoria-Witbank-Heidelberg area

Abstract

The vegetation of the Ba and lb land types of the Pretoria-Witbank-Heidelberg area was classified by means of Braun - Blanquet and TWINSPAN procedures. Releves were compiled in 265 stratified random sample plots.Stratification was firstly done by means of land types and secondly by terrain units. In each sample plot the floristic composition was recorded and a cover-abundance value, according to the Braun - Blanquet scale, was allocated to each species. Information on various environmental variables was also collected. Two-way indicator species analysis (TWINSP AN) was applied to the floristic data set and the obtained phytosociological table was refined by the application of Braun - Blanquet procedures. The classification of the floristic data resulted in the recognition of eight vegetation units and several plant communities within these vegetation units. All identified plant communities were described and could be ecologically explained in terms of the physical environment.