Ruderal and degraded natural vegetation on vacant lots in the Potchefstroom Municipal Area, North West Province, South Africa

Relatively little is known about ruderal and degraded natural vegetation in urban open spaces in the Grassland Biome of South Africa. The classification of the vegetation on vacant lots 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 six communities and seven sub-communities, belonging to two main groups, namely degraded natural and ruderal communities, are recogised. The communities which are mainly characterised by one dominant species, a few abundant species and many species with low frequency, are described. Associated gradients in habitat or disturbances are identified by using an ordination algorithm (DECORANA). Possible dynamic relationships between the communities are also discusse

Vegetation analysis of Pedlar’s Bush, Mpumalanga, and its conservation

Little information is available on the forest vegetation of the Barberton and eastern Mpumalanga Mountains. The vegetation of Pedlar’s Bush was phytosociologically described as part of a study to determine the conservation potential of this forest. Relevés were compiled in forty one plots of 0.04ha each. The data were analysed according to TWINSPAN and Braun-Blanquet classification procedures. Two communities, four sub-communities and six variants were described in this forest fragment. Species richness of the communities was statistically compared. Floristic and environmental relationships were also identified by means of DECORANA ordination procedures Moisture, terrain type and natural disturbances were identified as important environmental factors in the distribution of communities

Pollen morphology and its taxonomic value in Brachylaena (Asteraceae) in southern Africa

The pollen morphology of all the southern African representatives of Brachylaena R. Br. was investigated using light and scanning electron microscopy. On the basis of pollen morphology it is possible to recognize two groups in the genus. B. discolor (including B. uniflora), B. elliptica, B. glabra, B. neriifolia and B. rotundata are included in Group I, while B. huillensis and B. ilicifolia are the only representatives of Group II. The differences between the groups primarily concern length and width of colpi, shape of colpus ends, length and width of spinulae, frequency of spinulae, finer tectum sculpture and exine stratification. The possible taxonomic significance of pollen morphology is briefly discussed

Political legacy of South Africa affects the plant diversity patterns of urban domestic gardens along a socio-economic gradient

Socioeconomic and cultural influences within the study area influenced plant diversity patterns, showing higher species richness in the more affluent, white-dominated suburbs. However, much of the plant diversity of affluent suburbs is made up of alien species, whereas utilitarian and indigenous plants are strongly associated with the lower socio-economic status of black suburbs. This study provides evidence of the effects that socio-economic factors can have on vegetation patterns, rather than ecological factors, which are more often investigated. Anthropogenic influences are one of the most dominant and persistent driving forces of species richness within urban areas

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

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

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

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