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Item Fine-scale habitat requirements of the Heidelberg Opal butterfly (Chrysoritis aureus) in Gauteng and Mpumalanga, South Africa.(South African National Biodversity Institute (SANBI), 2017-09-11)Background: This study quantified the fine-scale habitat requirements of Chrysoritis aureus, at 11 known habitats in Gauteng and Mpumalanga, South Africa, in order to make habitat management recommendations for this endangered species. Objectives: The habitats were quantified in terms of plant species composition and structure with reference to their environmental characteristics. Method: A modified area-based phytosociological approach was used to collect floristic data along with environmental characteristics of habitats occurring on the Witwatersrand and Ventersdorp Geological Systems. Results: Species recorded were predominantly forbs and graminoids with a slightly higher number of plant species in the habitats of the Ventersdorp Geological System. Few dwarf shrubs and shrubs and very few trees were recorded. A higher number of plant species were recorded during the late growing season on both geological systems. The butterfly food plant Clutia pulchella var. pulchella L. (Euphorbiaceae) was recorded in all the habitats and was dominant in habitats in both geological systems. The occurrence of the food plant is essential for the survival of the butterfly at these habitats. Conclusion: Monitoring of the C. aureus butterfly populations and of the vegetation structure, species composition and growth forms to determine trends in the vegetation condition after planned fires; regular burning of the habitats in order to maintain suitable vegetation composition and structure; and the monitoring and eradication of alien invader plants are very important management activities to ensure the conservation of C. aureus.Item Germination characteristics of dimorphic honeybush (Cyclopia spp.) seed.(Elsevier B.V., 2016-04-09)Cyclopia is a genus of leguminous shrubs endemic to the fynbos biome of South Africa. Cyclopia spp. are used to make honeybush tea for which a high market demand has led to the overharvesting of Cyclopia species in the wild. Consequently, it has become important to study the cultivation requirements of honeybush in order to support farmers with the cultivation of this crop. Honeybush seeds are known to have either physical or combinational dormancy upon maturity, depending on the species. The plants also produce colour-dimorphic (green and brown), mature seeds in the same pod. A study of honeybush (Cyclopia maculata, Cyclopia genistoides and Cyclopia subternata) seed anatomy was carried out using light and dissection microscopy. It is hypothesized that seed physical dormancy is attributable to a relatively thick (3.5 μm) cuticular layer of the integument, a layer of macrosclereid cells, and the presence of a hygroscopically activated hilar valve. There is an absence of other structural openings by which moisture may enter the seed. No consistent structural differences were found amongst the three species or their colour-dimorphic seed. Seeds of the same three honeybush species were divided by colour and their germination response to selected variables (scarification, stratification, seed age and germination temperature) was evaluated. Three dormancy-breaking treatments (wet heat, dry heat and microwave energy) were identified as potential alternatives to conventional sulphuric acid scarification. Highest germination percentage of scarified seed for the three species tested was obtained after 3 weeks of cold stratification at 2 °C and incubated at 15 °C. Brown C. subternata seeds stored for three years gave a significantly higher germination percentage than seed stored for one year only. In non-treated seed, brown seeds had a higher germination percentage than green seeds. In treated seed (i.e. scarified and/or stratified), green seeds had a better germination percentage than brown seeds.Item The phytosociology of the Villiers - Grootvlei area, South Africa: The plant communities of the Ib land type.(Elsevier, 2017-01-27)The vegetation of the Ib Land Type in the Villiers - Grootvlei area was classified by means of the Braun Blanquet method. A total of 41 releves in this land type were used. Six main plant communities were identified, with one of the communities divided into two sub-communities. The plant communities were related to specific environmental conditions that were confirmed by the ordination (DECORANA) of the data.Item Identifying potential protected areas in the Grassland Biome of South Africa.(Academy of Science of South Africa (Commercial Publishers), 2020-08-17)South Africa is considered to be one of the most biologically diverse countries in the world. The conversion, degradation, and fragmentation of natural habitats have caused a loss of biodiversity in many areas. Grasslands have been widely recognised as important for both biodiversity and economic development. Many conservation efforts have in the past been theory driven, without actionable, feasible results. We hypothesised that correct implementation of the available data will indicate where conservation efforts should be focused to move closer to achieving targets for biodiversity conservation in the Grassland Biome in South Africa. We identified an area (near Heilbron and Petrus Steyn in the Free State) that is representative of the biodiversity in the region and is suitable for modern conservation efforts in the ‘real world’. This approach provides a practical look at conservation in the modern era and a feasible result for conservation efforts. Significance: • An area in the Free State Province was identified that has a high level of biodiversity representative of the Grassland Biome in South Africa. A subjective process was implemented to ensure that the area represents the factors that are considered important for conservation, land use and appropriate location in order to make the area a feasible target for conservation. The result therefore represents not only a theoretical finding that is based on data analysis, but also a practical approach to ensure that the findings can be implemented. This study is an effort to provide a baseline for a more modern approach to conservation, in which current land use, economic value and conservation value are all considered to achieve a sustainable result in terms of the conservation of biodiversity.Item Macro channel riparian vegetation of the Olifants River System in the Savanna Biome, Mpumalanga.(Aosis, 2004-12-18)The vegetation associated with the macro channel of the Olifants River System was investigated to identify plant communities mappable at a spatial scale of 1:250 000. The results obtained by applying the PHYTOTAB PC classification and mapping program package revealed nine distinct plant communities associated with that section of the river system that flows through the Savanna Biome.
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