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Quantifying Acacia defences : understanding the role of hooks, spines and architecture
The effectiveness of the structural defences of Acacias vary within and between species as a result of differences in thorn type (hooks versus spines) and branching architecture. This study aims to develop methods for quantifying the effectiveness of defences, thereby allowing for comparisons betwee...
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| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2017
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| _version_ | 1867613328271998976 |
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| access_status_str | Open Access |
| author | Hempson, Gareth |
| author2 | Kruger, Laurence |
| author_browse | Hempson, Gareth Kruger, Laurence |
| author_facet | Kruger, Laurence Hempson, Gareth |
| author_sort | Hempson, Gareth |
| collection | Thesis |
| description | The effectiveness of the structural defences of Acacias vary within and between species as a result of differences in thorn type (hooks versus spines) and branching architecture. This study aims to develop methods for quantifying the effectiveness of defences, thereby allowing for comparisons between individuals and localities. Measurements of a range of thorn and branching parameters of eight Acacia species were used to calculate three indices (stripping, biting and branching) describing different components of Acacia structural defences. These were combined to form an overall defence index that was tested against the results of three feeding simulation tests as well as actual animal feeding rates obtained from trials using nyala held in bomas. The stripping, biting and branching indices were shown to provide a good measure of the different components of a structural defence, although the scaling of their contribution to an overall defence index is complicated by variation in the suite of browsers and the resources available at a locality. The indices developed in this study provide a useful tool for assessing the role of large mammal herbivory in different environments when attempting to understand variation in the life history strategies of Acacias. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/26121 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:23.309Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| 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:11427/26121 Quantifying Acacia defences : understanding the role of hooks, spines and architecture Hempson, Gareth Kruger, Laurence Bond, William J Midgley, Jeremy J Systematics and Biodiversity Sciences Plant Ecology The effectiveness of the structural defences of Acacias vary within and between species as a result of differences in thorn type (hooks versus spines) and branching architecture. This study aims to develop methods for quantifying the effectiveness of defences, thereby allowing for comparisons between individuals and localities. Measurements of a range of thorn and branching parameters of eight Acacia species were used to calculate three indices (stripping, biting and branching) describing different components of Acacia structural defences. These were combined to form an overall defence index that was tested against the results of three feeding simulation tests as well as actual animal feeding rates obtained from trials using nyala held in bomas. The stripping, biting and branching indices were shown to provide a good measure of the different components of a structural defence, although the scaling of their contribution to an overall defence index is complicated by variation in the suite of browsers and the resources available at a locality. The indices developed in this study provide a useful tool for assessing the role of large mammal herbivory in different environments when attempting to understand variation in the life history strategies of Acacias. 2017-11-10T06:34:52Z 2017-11-10T06:34:52Z 2004 2017-03-10T14:51:00Z Bachelor Thesis Honours BSc (Hons) http://hdl.handle.net/11427/26121 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Systematics and Biodiversity Sciences Plant Ecology Hempson, Gareth Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| thesis_degree_str | Bachelor's / Honours |
| title | Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| title_full | Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| title_fullStr | Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| title_full_unstemmed | Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| title_short | Quantifying Acacia defences : understanding the role of hooks, spines and architecture |
| title_sort | quantifying acacia defences understanding the role of hooks spines and architecture |
| topic | Systematics and Biodiversity Sciences Plant Ecology |
| url | http://hdl.handle.net/11427/26121 |
| work_keys_str_mv | AT hempsongareth quantifyingacaciadefencesunderstandingtheroleofhooksspinesandarchitecture |