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Vegetation patterns and plant reproductive processes in the succulent Karoo
This thesis focuses on vegetation patterns and plant reproductive processes at the Tierberg Karoo Research Centre (33°1 0'S, 22°17'E) in the semi-arid southern Succulent Karoo, South Africa. It begins with an investigation into the roles of soil properties and competition in explaining variation in...
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| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2016
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| _version_ | 1867614380985679872 |
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| access_status_str | Open Access |
| author | Esler, Karen Joan |
| author2 | Cowling, Richard M |
| author_browse | Cowling, Richard M Esler, Karen Joan |
| author_facet | Cowling, Richard M Esler, Karen Joan |
| author_sort | Esler, Karen Joan |
| collection | Thesis |
| description | This thesis focuses on vegetation patterns and plant reproductive processes at the Tierberg Karoo Research Centre (33°1 0'S, 22°17'E) in the semi-arid southern Succulent Karoo, South Africa. It begins with an investigation into the roles of soil properties and competition in explaining variation in species distributions. The aim was to investigate changes in soil properties associated with species turnover (replacement series). Patterns of species abundances have been attributed to cyclic succession driven by disturbance and inter-specific competition. Areas where dominant species replaced each other over apparent edaphic discontinuities were investigated to test the roles of soil properties and competition in explaining variation in species distributions. Only soil pH differed significantly across the gradients studied. However, inter-and intra-specific· competitive interactions were also inferred. It was concluded that species distribution patterns resulted from the combined effects of edaphic factors and competition. The bulk of the thesis focuses on the reproductive biology of key species in the cyclic succession in order to understand the demographic processes underlying these patterns. The vegetation model proposes that heuweltjies (or mima-like mounds) are the source of disturbance which initiates the successional process. A study of reproductive attributes of dominant species occurring on and off heuweltjies indicated that species occurring on heuweltjies had opportunistic life-history traits; seeds did not germinate readily and canopy seed banks were maintained. Species off heuweltjies had higher overall germination and did not maintain seed banks in the plant canopies. The differences in reproductive attributes were related to competition and disturbance. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/21846 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:51:08.097Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Department of Biological Sciences |
| publisherStr | Department of Biological Sciences |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/21846 Vegetation patterns and plant reproductive processes in the succulent Karoo Esler, Karen Joan Cowling, Richard M Botany This thesis focuses on vegetation patterns and plant reproductive processes at the Tierberg Karoo Research Centre (33°1 0'S, 22°17'E) in the semi-arid southern Succulent Karoo, South Africa. It begins with an investigation into the roles of soil properties and competition in explaining variation in species distributions. The aim was to investigate changes in soil properties associated with species turnover (replacement series). Patterns of species abundances have been attributed to cyclic succession driven by disturbance and inter-specific competition. Areas where dominant species replaced each other over apparent edaphic discontinuities were investigated to test the roles of soil properties and competition in explaining variation in species distributions. Only soil pH differed significantly across the gradients studied. However, inter-and intra-specific· competitive interactions were also inferred. It was concluded that species distribution patterns resulted from the combined effects of edaphic factors and competition. The bulk of the thesis focuses on the reproductive biology of key species in the cyclic succession in order to understand the demographic processes underlying these patterns. The vegetation model proposes that heuweltjies (or mima-like mounds) are the source of disturbance which initiates the successional process. A study of reproductive attributes of dominant species occurring on and off heuweltjies indicated that species occurring on heuweltjies had opportunistic life-history traits; seeds did not germinate readily and canopy seed banks were maintained. Species off heuweltjies had higher overall germination and did not maintain seed banks in the plant canopies. The differences in reproductive attributes were related to competition and disturbance. 2016-09-20T12:34:55Z 2016-09-20T12:34:55Z 1993 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/21846 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Botany Esler, Karen Joan Vegetation patterns and plant reproductive processes in the succulent Karoo |
| thesis_degree_str | Doctoral |
| title | Vegetation patterns and plant reproductive processes in the succulent Karoo |
| title_full | Vegetation patterns and plant reproductive processes in the succulent Karoo |
| title_fullStr | Vegetation patterns and plant reproductive processes in the succulent Karoo |
| title_full_unstemmed | Vegetation patterns and plant reproductive processes in the succulent Karoo |
| title_short | Vegetation patterns and plant reproductive processes in the succulent Karoo |
| title_sort | vegetation patterns and plant reproductive processes in the succulent karoo |
| topic | Botany |
| url | http://hdl.handle.net/11427/21846 |
| work_keys_str_mv | AT eslerkarenjoan vegetationpatternsandplantreproductiveprocessesinthesucculentkaroo |