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A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa
This study was carried out on Sand Plain Lowland fynbos at Pella from April to September 1988. Environmental factors, nitrogen and phosphorus pool sizes and mineralization processes were investigated in the surface soils (1-10cm) of 7-8 year old fynbos vegetation and an adjacent Acacia saligna (Labi...
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| Format: | Thesis |
| Language: | English |
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Department of Biological Sciences
2017
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| _version_ | 1867613268531478528 |
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| access_status_str | Open Access |
| author | Wienand, Karen Tania |
| author2 | Stock, William D |
| author_browse | Stock, William D Wienand, Karen Tania |
| author_facet | Stock, William D Wienand, Karen Tania |
| author_sort | Wienand, Karen Tania |
| collection | Thesis |
| description | This study was carried out on Sand Plain Lowland fynbos at Pella from April to September 1988. Environmental factors, nitrogen and phosphorus pool sizes and mineralization processes were investigated in the surface soils (1-10cm) of 7-8 year old fynbos vegetation and an adjacent Acacia saligna (Labill.) Wendl. infestation. While there was no significant difference in soil temperature between fynbos and acacia sites, soil moisture and organic matter content was significantly higher in the acacia soils. This favoured decomposition so that soil nutrient analyses showed enrichment of the soils (higher N and P) by the acacia infestation. Soil N and P mineralization was assayed using in situ incubations. Due to their higher soil total N concentrations, acacia soils showed greater inorganic N concentrations. In both acacia and fynbos soils ammonium was the dominant N form. This was ascribed to the high soil moisture content, while the low temperatures appeared to be the factor most strongly influencing ammonium accumulation. The low nitrate accumulations even in the field incubations indicated that the nitrification process was inhibited, probably by the high soil moisture content and low temperatures. The variable patterns of inorganic P accumulation were ascribed mainly to fluctuations between microbial mineralization and immobilization. Contrary to the hypothesis that the higher soil organic matter and greater concentrations of total N and Pin acacia soils would result in higher mineralization rates, there was no significant difference in the rates of N and P mineralization between fynbos and acacia soils. Thus, it was concluded that the higher decomposition rates in acacia soils was not associated with greater mineralization rates during the wet season (period of study). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/25891 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:26.520Z |
| 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:11427/25891 A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa Wienand, Karen Tania Stock, William D Botany Ecophysiology This study was carried out on Sand Plain Lowland fynbos at Pella from April to September 1988. Environmental factors, nitrogen and phosphorus pool sizes and mineralization processes were investigated in the surface soils (1-10cm) of 7-8 year old fynbos vegetation and an adjacent Acacia saligna (Labill.) Wendl. infestation. While there was no significant difference in soil temperature between fynbos and acacia sites, soil moisture and organic matter content was significantly higher in the acacia soils. This favoured decomposition so that soil nutrient analyses showed enrichment of the soils (higher N and P) by the acacia infestation. Soil N and P mineralization was assayed using in situ incubations. Due to their higher soil total N concentrations, acacia soils showed greater inorganic N concentrations. In both acacia and fynbos soils ammonium was the dominant N form. This was ascribed to the high soil moisture content, while the low temperatures appeared to be the factor most strongly influencing ammonium accumulation. The low nitrate accumulations even in the field incubations indicated that the nitrification process was inhibited, probably by the high soil moisture content and low temperatures. The variable patterns of inorganic P accumulation were ascribed mainly to fluctuations between microbial mineralization and immobilization. Contrary to the hypothesis that the higher soil organic matter and greater concentrations of total N and Pin acacia soils would result in higher mineralization rates, there was no significant difference in the rates of N and P mineralization between fynbos and acacia soils. Thus, it was concluded that the higher decomposition rates in acacia soils was not associated with greater mineralization rates during the wet season (period of study). 2017-10-30T10:32:39Z 2017-10-30T10:32:39Z 1988 2017-03-07T12:29:28Z Bachelor Thesis Honours BSc (Hons) http://hdl.handle.net/11427/25891 eng application/pdf Department of Biological Sciences Faculty of Science University of Cape Town |
| spellingShingle | Botany Ecophysiology Wienand, Karen Tania A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| thesis_degree_str | Bachelor's / Honours |
| title | A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| title_full | A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| title_fullStr | A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| title_full_unstemmed | A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| title_short | A preliminary study of the impacts of alien Acacia infestation (A saligna) on the relative rates of nitrogen and phosphorus cycling in Lowland Fynbos, southwestern Cape, South Africa |
| title_sort | preliminary study of the impacts of alien acacia infestation a saligna on the relative rates of nitrogen and phosphorus cycling in lowland fynbos southwestern cape south africa |
| topic | Botany Ecophysiology |
| url | http://hdl.handle.net/11427/25891 |
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