The vegetation of the habitat of the Brenton blue butterfly, Orachrysops niobe (Trimen), in the Western Cape, South Africa
- Lubke, Roy, Hoare, D, Victor, J, Ketelaar, R
- Authors: Lubke, Roy , Hoare, D , Victor, J , Ketelaar, R
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6524 , http://hdl.handle.net/10962/d1005957
- Description: The Brenton blue butterfly is known only from a small population in one hectare of asteraceous coastal fynbos at Brenton-on-Sea. This fynbos is characterized by a great diversity of shrubs, herbs and graminoids, with a successional gradient to thicket where Pterocelastrus tricuspidatus is dominant. The eggs of the butterfly are laid on the lower side of the leaves of Indigofera erecta, on which the larvae feed. Fifteen 1-m² quadrats containing plants of Indigofera erecta with and without eggs of the butterfly were distinguished and sampled separately from 15 1-m² quadrats containing plants of Indigofera erecta without eggs. No marked differences in total vegetation, shrub or herb cover between the sites with and without eggs were observed. There was a difference in abundance of the fern Pteridium aquilinum, with over 30% cover at sites with no eggs and only about 6% at sites with eggs present. This could reflect the absence of other plants where the ferns had such dense cover.
- Full Text:
- Date Issued: 2003
- Authors: Lubke, Roy , Hoare, D , Victor, J , Ketelaar, R
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6524 , http://hdl.handle.net/10962/d1005957
- Description: The Brenton blue butterfly is known only from a small population in one hectare of asteraceous coastal fynbos at Brenton-on-Sea. This fynbos is characterized by a great diversity of shrubs, herbs and graminoids, with a successional gradient to thicket where Pterocelastrus tricuspidatus is dominant. The eggs of the butterfly are laid on the lower side of the leaves of Indigofera erecta, on which the larvae feed. Fifteen 1-m² quadrats containing plants of Indigofera erecta with and without eggs of the butterfly were distinguished and sampled separately from 15 1-m² quadrats containing plants of Indigofera erecta without eggs. No marked differences in total vegetation, shrub or herb cover between the sites with and without eggs were observed. There was a difference in abundance of the fern Pteridium aquilinum, with over 30% cover at sites with no eggs and only about 6% at sites with eggs present. This could reflect the absence of other plants where the ferns had such dense cover.
- Full Text:
- Date Issued: 2003
Analysis of the calling songs of Platypleura hirtipennis (Germar, 1834) and P. plumosa (Germar, 1834) (Hemiptera: Cicadidae)
- Sanborn, Allen F, Phillips, P K, Villet, Martin H
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
The inception phase of a case study of outcomes - based education assessment policy in the Human and Social Sciences Learning Area of C2005
- Authors: Wilmot, P Dianne
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6107 , http://hdl.handle.net/10962/d1009736
- Description: This article describes the Inception Phase (January to December 2002) of an ongoing research project focused on the Grade 9 Learning Area of Human and Social Sciences of Curriculum 2005. The case study involves a dynamic interaction between a university lecturer, playing the role of 'outside facilitator', and the History and Geography teachers at two independent schools. The article describes how teachers in a given context respond to outcomes-based education assessment policy, and the tools and processes they use to develop the deep understanding inferred by policy (Republic of South Africa, 2000) to implement change in a meaningful way. The article consists of three sections. The first contextualises significant events which foregrounded and provided the impetus for the research project. It provides an overview of the theory informing the research and the goals of the research. The second analyses in narrative form the various stages of the Inception Phase. It describes a process of curriculum development which has involved the development of criterion- referenced assessment rubrics, a Learner and Curriculum Profile, and an audit of current assessment practices in History and Geography at the two schools. The article illuminates the time and effort necessary for creative and systemic curriculum innovation. The final section synthesizes the information gathered.
- Full Text:
- Date Issued: 2003
- Authors: Wilmot, P Dianne
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6107 , http://hdl.handle.net/10962/d1009736
- Description: This article describes the Inception Phase (January to December 2002) of an ongoing research project focused on the Grade 9 Learning Area of Human and Social Sciences of Curriculum 2005. The case study involves a dynamic interaction between a university lecturer, playing the role of 'outside facilitator', and the History and Geography teachers at two independent schools. The article describes how teachers in a given context respond to outcomes-based education assessment policy, and the tools and processes they use to develop the deep understanding inferred by policy (Republic of South Africa, 2000) to implement change in a meaningful way. The article consists of three sections. The first contextualises significant events which foregrounded and provided the impetus for the research project. It provides an overview of the theory informing the research and the goals of the research. The second analyses in narrative form the various stages of the Inception Phase. It describes a process of curriculum development which has involved the development of criterion- referenced assessment rubrics, a Learner and Curriculum Profile, and an audit of current assessment practices in History and Geography at the two schools. The article illuminates the time and effort necessary for creative and systemic curriculum innovation. The final section synthesizes the information gathered.
- Full Text:
- Date Issued: 2003
Implications of a new 40Ar/ 39Ar age for a basalt flow interbedded with the Etjo Formation, Northeast Namibia
- Marsh, Julian S, Swart, Roger S, Phillips, D
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
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