'Rich man poor man': inter-household and community factors influencing the use of wild plant resources amongst rural households in South Africa
- Authors: Cocks, Michelle L , Bangay, Lindsey , Shackleton, Charlie M , Wiersum, K Freerk
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141211 , vital:37953 , DOI: 10.3843/SusDev.15.3:3
- Description: Biodiversity is recognised as an integral part of people's daily livelihoods. This study therefore aims to understand the use of NTFPs at an intricate level by determining what role these resources fulfil in six rural villages and 1011 households' livelihoods. It examines how the use of NTFPs are influenced by intra-household variables, such as wealth and gender, and inter-community variables, such as accessibility to the natural resource. The results reveal that approximately 4453 kg of wild material is used annually per household, of which 1598 kg is used for cultural purposes. The influence of vegetation type and differences between villages are statistically more significant than inter-household variables. At an inter-household level, an increase in the financial status of households did not result in a decrease in the use of natural resources, nor in the quantity of material used.
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- Date Issued: 2010
Handling multiple levels of data and multiple research questions in an embedded case study : methodological challenges
- Authors: Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6247 , http://hdl.handle.net/10962/d1007865
- Description: Hougaard et al. report an embedded case study in which nine socially phobic clients were treated as part of a therapy program, which incorporated individual and group therapy and which was largely delivered by trainee clinicians. An important focus of the report is on the effectiveness of their treatment model. This commentary draws attention to the size and complexity of the available data, and it suggests ways in which the use of a more explicitly interpretative methodology can draw out additional dimensions of the data and allow a more systematic contribution to be made to the development of clinical theory.
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- Date Issued: 2008
Mimics and magnets : The importance of color and ecological facilitation in floral deception
- Authors: Peter, Craig I , Johnson, Steven D
- Date: 2008
- Identifier: vital:6536 , http://hdl.handle.net/10962/d1005977
- Description: Plants that lack floral rewards can attract pollinators if they share attractive floral signals with rewarding plants. These deceptive plants should benefit from flowering in close proximity to such rewarding plants, because pollinators are locally conditioned on floral signals of the rewarding plants (mimic effect) and because pollinators are more abundant close to rewarding plants (magnet effect). We tested these ideas using the non-rewarding South African plant Eulophia zeyheriana (Orchidaceae) as a study system. Field observations revealed that E. zeyheriana is pollinated solely by solitary bees belonging to a single species of Lipotriches (Halictidae) that appears to be closely associated with the flowers of Wahlenbergia cuspidata (Campanulaceae), a rewarding plant with which the orchid is often sympatric. The pale blue color of the flowers of E. zeyheriana differs strongly from flowers of its congeners, but is very similar to that of flowers of W. cuspidata. Analysis of spectral reflectance patterns using a bee vision model showed that bees are unlikely to be able to distinguish the two species in terms of flower color. A UV-absorbing sunscreen was applied to the flowers of the orchid in order to alter their color, and this resulted in a significant decline in pollinator visits, thus indicating the importance of flower color for attraction of Lipotriches bees. Pollination success in the orchid was strongly affected by proximity to patches of W. cuspidata. This was evident from one of two surveys of natural populations of the orchid, as well as experiments in which we translocated inflorescences of the orchid either into patches of W. cuspidata or 40 m outside such patches. Flower color and location of E. zeyheriana plants relative to rewarding magnet patches are therefore key components of the exploitation by this orchid of the relationship between W. cuspidata and Lipotriches bee pollinators.
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- Date Issued: 2008
The effects of load and gradient on hand force responses during dynamic pushing and pulling tasks
- Authors: Bennett, Anthea I , Desai, Sheena D , Todd, Andrew I , Freeland, H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6757 , http://hdl.handle.net/10962/d1009459
- Description: The limited attention afforded to push/pull activities and the motion phases (initial, sustained and ending) characteristic of these tasks has prompted a research focus in this area. The present study examined biomechanical responses in the form of hand forces during dynamic submaximal trolley pushing and pulling. Participants pushed/pulled loads of 100, 200 and 300 kg on the level (determining impact of load) or pushed 100 kg along a 12° ramp (uphill and downhill- determining impact of gradient). During level exertions significant differences (p<0.05) in hand forces occurred between loads of 100 and 200 kg, and 100 and 300 kg for initial and sustained forces but not ending forces. Values were similar for pushing and pulling at respective loads and motion phases. Strong correlations indicate that initial forces can be used to accurately estimate sustained and ending forces. Importantly, correct technique is essential in force reduction. Forces were highest during uphill initial and sustained phases and the downhill sustained phase. For the initial phase, the forces were highest during uphill pushing (86.5 ± 25.73 N); for the sustained phase, there was no difference between uphill and downhill forces but level forces were significantly lower (18.19 ± 8.09 N) than either of the other two conditions; for the ending phase, the highest forces were produced during downhill pushing (-53.34 ± 13.65N). As sustained forces equaled or exceeded initial forces for uphill and downhill efforts, consideration of sustained forces may be appropriate in determining the inherent potential risk of graded pushing.
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- Date Issued: 2008