Electrochemical and photophysical characterization of non-peripherally-octaalkyl substituted dichlorotin (IV) phthalocyanine and tetrabenzotriazaporphyrin compounds
- Khene, Samson M, Cammidge, Andrew N, Cook, Michael J, Nyokong, Tebello
- Authors: Khene, Samson M , Cammidge, Andrew N , Cook, Michael J , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271216 , vital:54522 , xlink:href="https://doi.org/10.1142/S1088424607000886"
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (3a), octahexyltetrabenzo-5,10,15- triazaporphyrinato dichlorotin(IV) (3b) and octadecylphthalocyaninato dichlorotin(IV) (3c) were synthesized and their photophysical and electrochemical behavior studied. Complex 3b, containing a CH group in place of one of the aza nitrogen atoms of the phthalocyanine core, shows a split Q-band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (3a and 3c). In contrast, 3b shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in tetrahydrofuran than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring-based redox processes.
- Full Text:
- Date Issued: 2007
- Authors: Khene, Samson M , Cammidge, Andrew N , Cook, Michael J , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271216 , vital:54522 , xlink:href="https://doi.org/10.1142/S1088424607000886"
- Description: Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (3a), octahexyltetrabenzo-5,10,15- triazaporphyrinato dichlorotin(IV) (3b) and octadecylphthalocyaninato dichlorotin(IV) (3c) were synthesized and their photophysical and electrochemical behavior studied. Complex 3b, containing a CH group in place of one of the aza nitrogen atoms of the phthalocyanine core, shows a split Q-band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (3a and 3c). In contrast, 3b shows a triplet quantum yield ΦT = 0.78. The triplet state lifetimes were solvent dependent, and were higher in tetrahydrofuran than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring-based redox processes.
- Full Text:
- Date Issued: 2007
Photophysical, photochemical and bovine serum albumin binding studies on water-soluble gallium (III) phthalocyanine derivatives
- Ogunsipe, Abimbola, Nyokong, Tebello, Durmus, Mahmut
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello , Durmus, Mahmut
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271239 , vital:54524 , xlink:href="https://doi.org/10.1142/S1088424607000746"
- Description: Spectral, photophysical, photochemical and bovine serum albumin binding studies on some gallium(III) derivatives - {1,(4)-(tetrapyridyloxyphthalocyaninato)gallium(III), (αGaPc); 2,(3)-(tetrapyridyloxyphthalocyaninato)gallium(III), (βGaPc); and their quaternized derivatives: QαGaPc and QβGaPc)} are hereby presented. β-Substituted complexes are more fluorescent, but show lower tendencies to undergo intersystem crossing than the α-substituted, as judged by their fluorescence and triplet quantum yield values. The quaternized derivatives (QGaPc) are water-soluble and non-aggregated, which makes them potential photosensitizers of choice for photodynamic therapy applications; these amphiphilic compounds also bind strongly to bovine serum albumin in 1:1 stoichiometries, and with binding constants (Kb) in the order of 106 M−1.
- Full Text:
- Date Issued: 2007
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello , Durmus, Mahmut
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271239 , vital:54524 , xlink:href="https://doi.org/10.1142/S1088424607000746"
- Description: Spectral, photophysical, photochemical and bovine serum albumin binding studies on some gallium(III) derivatives - {1,(4)-(tetrapyridyloxyphthalocyaninato)gallium(III), (αGaPc); 2,(3)-(tetrapyridyloxyphthalocyaninato)gallium(III), (βGaPc); and their quaternized derivatives: QαGaPc and QβGaPc)} are hereby presented. β-Substituted complexes are more fluorescent, but show lower tendencies to undergo intersystem crossing than the α-substituted, as judged by their fluorescence and triplet quantum yield values. The quaternized derivatives (QGaPc) are water-soluble and non-aggregated, which makes them potential photosensitizers of choice for photodynamic therapy applications; these amphiphilic compounds also bind strongly to bovine serum albumin in 1:1 stoichiometries, and with binding constants (Kb) in the order of 106 M−1.
- Full Text:
- Date Issued: 2007
Benthic mapping using local aerial photo interpretation and resident taxa inventories for designing marine protected areas
- Shankar, Aswani, Lauer, Matthew
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439059 , vital:73541 , xlink:href="https://doi.org/10.1017/S0376892906003183"
- Description: Given the frequent socioeconomic, political and concomitant ecological failures of science-driven marine protected area (MPA) programmes, it is now important to design MPAs by integrating natural and social science research more comprehensively. This study shows how indigenous peoples assisted in the design of MPAs by identifying marine substrates and related resident taxa on aerial photos, information which was then incorporated into a geographical information system (GIS) database, along with dive survey data. Two questions were asked: (1) Is indigenous ecological knowledge accurate enough for mapping the benthos and associated taxa? (2) Is such an approach an appropriate way for assisting in the biological and social design of MPAs in Oceania? Conventional quadrat field dive surveys were used to measure the accuracy of substrate identification by local informants and a visual survey was used to test hypotheses formulated from local knowledge regarding the spatial distribution and relative abundance of non-cryptic species within certain benthic habitats. Equivalence rates between indigenous aerial photo interpretations of dominant benthic substrates and in situ dive surveys were 75–85% for a moderately detailed classification scheme of the benthos, which included nine locally-defined abiotic and biotic benthic classes for the MPA seabed. Similarly, the taxa inventory showed a strong correspondence between the qualitative predictions of local fisherfolk and the quantitative analysis of non-cryptic species distribution, including their relative abundance and geophysical locations. Indigenous people's predictions about the presence or absence of fish in different benthic habitats corresponded 77% and 92% of the time (depending on scoring schema) with in situ visual measurements. These results demonstrate how incorporating local knowledge of benthic heterogeneity, existing biological communities, and particular spatio-temporal events of biological significance into a GIS database can corroborate the production of scientifically reliable base resource maps for designing MPAs in an environmentally and culturally sound fashion. This participatory approach was used to design and then establish MPAs in the Roviana and Vonavona region of the Western Solomon Islands. Under appropriate conditions, interdisciplinary work can complement the design of scientific fishery management and biodiversity conservation prescriptions for coastal Oceania.
- Full Text:
- Date Issued: 2006
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439059 , vital:73541 , xlink:href="https://doi.org/10.1017/S0376892906003183"
- Description: Given the frequent socioeconomic, political and concomitant ecological failures of science-driven marine protected area (MPA) programmes, it is now important to design MPAs by integrating natural and social science research more comprehensively. This study shows how indigenous peoples assisted in the design of MPAs by identifying marine substrates and related resident taxa on aerial photos, information which was then incorporated into a geographical information system (GIS) database, along with dive survey data. Two questions were asked: (1) Is indigenous ecological knowledge accurate enough for mapping the benthos and associated taxa? (2) Is such an approach an appropriate way for assisting in the biological and social design of MPAs in Oceania? Conventional quadrat field dive surveys were used to measure the accuracy of substrate identification by local informants and a visual survey was used to test hypotheses formulated from local knowledge regarding the spatial distribution and relative abundance of non-cryptic species within certain benthic habitats. Equivalence rates between indigenous aerial photo interpretations of dominant benthic substrates and in situ dive surveys were 75–85% for a moderately detailed classification scheme of the benthos, which included nine locally-defined abiotic and biotic benthic classes for the MPA seabed. Similarly, the taxa inventory showed a strong correspondence between the qualitative predictions of local fisherfolk and the quantitative analysis of non-cryptic species distribution, including their relative abundance and geophysical locations. Indigenous people's predictions about the presence or absence of fish in different benthic habitats corresponded 77% and 92% of the time (depending on scoring schema) with in situ visual measurements. These results demonstrate how incorporating local knowledge of benthic heterogeneity, existing biological communities, and particular spatio-temporal events of biological significance into a GIS database can corroborate the production of scientifically reliable base resource maps for designing MPAs in an environmentally and culturally sound fashion. This participatory approach was used to design and then establish MPAs in the Roviana and Vonavona region of the Western Solomon Islands. Under appropriate conditions, interdisciplinary work can complement the design of scientific fishery management and biodiversity conservation prescriptions for coastal Oceania.
- Full Text:
- Date Issued: 2006
Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets
- Khamanga, Sandile M, Walker, Roderick B
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184232 , vital:44192 , xlink:href="https://doi.org/10.1080/03639040600599822"
- Description: Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.
- Full Text:
- Date Issued: 2006
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184232 , vital:44192 , xlink:href="https://doi.org/10.1080/03639040600599822"
- Description: Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.
- Full Text:
- Date Issued: 2006
Synthesis, photophysicochemical studies of adjacently tetrasubstituted binaphthalo-phthalocyanines
- Seotsanyana-Mokhosi, Itumeleng, Chen, Ji-Yao, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289294 , vital:56616 , xlink:href="https://doi.org/10.1142/S108842460500040X"
- Description: Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.
- Full Text:
- Date Issued: 2005
- Authors: Seotsanyana-Mokhosi, Itumeleng , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289294 , vital:56616 , xlink:href="https://doi.org/10.1142/S108842460500040X"
- Description: Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.
- Full Text:
- Date Issued: 2005
Towards a better grasp of what matters in view of ‘the posts’
- O'Donoghue, Rob B, Lotz-Sisitka, Heila
- Authors: O'Donoghue, Rob B , Lotz-Sisitka, Heila
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182693 , vital:43854 , xlink:href="https://doi.org/10.1080/13504620500169593"
- Description: This response to McKenzie suggests that the issues of representivity, legitimacy and politics, inscribed within an institutional continuism characteristic of modernity within the McKenzie discourse, could well be recast within a reflexive view informed by insights derived with developing social theory. It briefly overviews the struggle for human agency that played out within the deconstructive engagements of the posts and probes how perspectives in social theory are opening the way for a break with features of environmental education as an institutional field. The review points to a reconstituting of the idea of environmental education research from scholastic field of/for environmental awareness and sustainable development, to a reflexive engagement within processes of social reproduction and reorientation in a changing world. A shift such as this would constitute a subtle change in a developing field of research, to situated design decisions of reflexive engagement (research) in social fields constituted within developing cultural contexts of risk.
- Full Text:
- Date Issued: 2005
- Authors: O'Donoghue, Rob B , Lotz-Sisitka, Heila
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182693 , vital:43854 , xlink:href="https://doi.org/10.1080/13504620500169593"
- Description: This response to McKenzie suggests that the issues of representivity, legitimacy and politics, inscribed within an institutional continuism characteristic of modernity within the McKenzie discourse, could well be recast within a reflexive view informed by insights derived with developing social theory. It briefly overviews the struggle for human agency that played out within the deconstructive engagements of the posts and probes how perspectives in social theory are opening the way for a break with features of environmental education as an institutional field. The review points to a reconstituting of the idea of environmental education research from scholastic field of/for environmental awareness and sustainable development, to a reflexive engagement within processes of social reproduction and reorientation in a changing world. A shift such as this would constitute a subtle change in a developing field of research, to situated design decisions of reflexive engagement (research) in social fields constituted within developing cultural contexts of risk.
- Full Text:
- Date Issued: 2005
The fuelwood crisis in southern Africa: Relating fuelwood use to livelihoods in a rural village
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
- Date Issued: 2004
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
- Date Issued: 2004
Iron perchlorophthalocyanine and tetrasulfophthalocyanine catalyzed oxidation of cyclohexane using hydrogen peroxide, chloroperoxybenzoic acid and tert-butylhydroperoxide as oxidants
- Grootboom, Natasha, Nyokong, Tebello
- Authors: Grootboom, Natasha , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289606 , vital:56653 , xlink:href="https://doi.org/10.1016/S1381-1169(01)00404-6"
- Description: Polychlorophthalocyanine (Cl16PcFeII) and tetrasulfophthalocyanine ([FeIITSPc]4−) complexes of iron are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), m-chloroperoxybenzoic acid (m-CPBA) and hydrogen peroxide as oxidants. Catalysis using the Cl16PcFeII was performed in a dimethylformamide:dichloromethane (3:7) solvent mixture. For the [FeIITSPc]4−catalyst, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative yields of the products depended on oxidant and the catalyst. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. The mechanism of the oxidation of cyclohexane in the presence of the Cl16PcFeII and [FeIITSPc]4− involves the oxidation of these catalysts, forming an Fe(III) phthalocyanine species as an intermediate. Higher yields were observed when [FeTSPc]4− was employed as a catalyst, which is more soluble than the perchlorinated iron phthalocyanine catalyst.
- Full Text:
- Date Issued: 2002
- Authors: Grootboom, Natasha , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289606 , vital:56653 , xlink:href="https://doi.org/10.1016/S1381-1169(01)00404-6"
- Description: Polychlorophthalocyanine (Cl16PcFeII) and tetrasulfophthalocyanine ([FeIITSPc]4−) complexes of iron are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), m-chloroperoxybenzoic acid (m-CPBA) and hydrogen peroxide as oxidants. Catalysis using the Cl16PcFeII was performed in a dimethylformamide:dichloromethane (3:7) solvent mixture. For the [FeIITSPc]4−catalyst, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative yields of the products depended on oxidant and the catalyst. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. The mechanism of the oxidation of cyclohexane in the presence of the Cl16PcFeII and [FeIITSPc]4− involves the oxidation of these catalysts, forming an Fe(III) phthalocyanine species as an intermediate. Higher yields were observed when [FeTSPc]4− was employed as a catalyst, which is more soluble than the perchlorinated iron phthalocyanine catalyst.
- Full Text:
- Date Issued: 2002
Use patterns and value of savanna resources in three rural villages in South Africa
- Shackleton, Sheona E, Shackleton, Charlie M, Netshiluvhi, T R, Geach, B S, Ballance, A, Fairbanks, D H K
- Authors: Shackleton, Sheona E , Shackleton, Charlie M , Netshiluvhi, T R , Geach, B S , Ballance, A , Fairbanks, D H K
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182384 , vital:43825 , xlink:href="https://doi.org/10.1663/0013-0001(2002)056[0130:UPAVOS]2.0.CO;2"
- Description: Rural communities in South Africa harvest a diversity of wild resources from communal woodlands for home consumption and sale. The contribution these resources make to the rural economy has been little recognized, and few studies have attempted to place a monetary value on this use. This paper describes three case studies which aimed to determine the value of savanna resources for the livelihoods of rural households. Use patterns and values of resources in three villages of differing socioeconomic status were determined using household interviews, PRA techniques and key informant interviews. Questions were designed to establish the types of products used, frequency of use, quantities used, seasonality of use, longevity of durable resources, local prices, and the extent of trade. All households were procuring at least some woodland resources, with the most frequently used being fuel wood, wood for implements, edible herbs and fruits, grass for brushes, and insects. Patterns of resource use varied across villages. The most “rural” village used the greatest diversity of resources and had the highest number of users for most resources. Gross value of resources consumed per household per year ranged from R28I9 to R7238. Total value was highest in the less obviously resource dependent village, primarily the result of higher local prices due to greater extraction costs and a larger market for traded goods. Values are comparable to those contributed by other land-based livelihood activities such as subsistence cultivation and livestock production.
- Full Text:
- Date Issued: 2002
- Authors: Shackleton, Sheona E , Shackleton, Charlie M , Netshiluvhi, T R , Geach, B S , Ballance, A , Fairbanks, D H K
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182384 , vital:43825 , xlink:href="https://doi.org/10.1663/0013-0001(2002)056[0130:UPAVOS]2.0.CO;2"
- Description: Rural communities in South Africa harvest a diversity of wild resources from communal woodlands for home consumption and sale. The contribution these resources make to the rural economy has been little recognized, and few studies have attempted to place a monetary value on this use. This paper describes three case studies which aimed to determine the value of savanna resources for the livelihoods of rural households. Use patterns and values of resources in three villages of differing socioeconomic status were determined using household interviews, PRA techniques and key informant interviews. Questions were designed to establish the types of products used, frequency of use, quantities used, seasonality of use, longevity of durable resources, local prices, and the extent of trade. All households were procuring at least some woodland resources, with the most frequently used being fuel wood, wood for implements, edible herbs and fruits, grass for brushes, and insects. Patterns of resource use varied across villages. The most “rural” village used the greatest diversity of resources and had the highest number of users for most resources. Gross value of resources consumed per household per year ranged from R28I9 to R7238. Total value was highest in the less obviously resource dependent village, primarily the result of higher local prices due to greater extraction costs and a larger market for traded goods. Values are comparable to those contributed by other land-based livelihood activities such as subsistence cultivation and livestock production.
- Full Text:
- Date Issued: 2002
Woodlands in South Africa and the national forests act
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182065 , vital:43796 , xlink:href="https://doi.org/10.1080/10295925.2000.9631252"
- Description: The development of the National Forestry Action Programme (NFAP) and promulgation of the National Forests Act (NFA) have established a new vision for the care, management and distribution of benefits from South Africa's woodlands. The Department of water Affairs and Forestry is mandated with ensuring this vision is put into practice. However, historically the Department has had little to do with woodlands, and suffers from a lack of capacity and expertise, a situation which it readily acknowledges. Additionally, the legal definition of a woodland within the NFA is problematic. Within this context, this paper examines oft cited definitions of woodlands and seeks to find an appropriate one for the South African context. It then briefly reviews the major classifications of woodland types at a national scale, as the minimum basis for homogenous reporting units for which monitoring of the success of the NFAP and the NFA should be pursued. Finally, a brief description of moist/dystrophic and arid/eutrophic woodlands is presented.
- Full Text:
- Date Issued: 2000
- Authors: Shackleton, Charlie M
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182065 , vital:43796 , xlink:href="https://doi.org/10.1080/10295925.2000.9631252"
- Description: The development of the National Forestry Action Programme (NFAP) and promulgation of the National Forests Act (NFA) have established a new vision for the care, management and distribution of benefits from South Africa's woodlands. The Department of water Affairs and Forestry is mandated with ensuring this vision is put into practice. However, historically the Department has had little to do with woodlands, and suffers from a lack of capacity and expertise, a situation which it readily acknowledges. Additionally, the legal definition of a woodland within the NFA is problematic. Within this context, this paper examines oft cited definitions of woodlands and seeks to find an appropriate one for the South African context. It then briefly reviews the major classifications of woodland types at a national scale, as the minimum basis for homogenous reporting units for which monitoring of the success of the NFAP and the NFA should be pursued. Finally, a brief description of moist/dystrophic and arid/eutrophic woodlands is presented.
- Full Text:
- Date Issued: 2000