Urban nature conservation: vegetation of natural areas in the Potchefstroom municipal area, North West Province, South Africa

Abstract

This study on the natural and degraded natural vegetation of natural areas in the Potchefstroom Municipal Area, forms part of a research programme on spontaneous vegetation in urban open spaces in the North West Province, South Africa. Using a numerical classification technique (TWINSPAN) as a first approximation, the classification was refined by applying Braun-Blanquet procedures. The result is a phytosociological table from which 6 plant communities were recognised, which are subdivided in sub-communities and variants, resulting in 18 vegetation units. Some of these vegetation units are similar to communities described previously in natural areas. The presence of degraded natural communities suggests huge anthropogenic influences in certain areas. An ordination (DECORANA) scatter diagram shows the distribution of the plant communities along gradients which could be related to vegetation structure, altitude, soil depth, rockiness of soil surface, wetness or dryness of the habitat and number of introduced species. This study contributes to the compilation of a guideline for a conservation orientated management plan for the area, but also created a wealth of new knowledge of the reaction of indigenous plant species under disturbed conditions.

Keywords

• Braun-Blanquet, DECORANA, habitat fragmentation, MEGATAB, nature conservation, plant communities,TURBOVEG, TWINSPAN