Estimating the potential role of commercial over-harvesting in resource viability: A case study of five useful tree species in South Africa
- Shackleton, Charlie M, Guthrie, G, Main, R
- Authors: Shackleton, Charlie M , Guthrie, G , Main, R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181324 , vital:43719 , xlink:href="https://doi.org/10.1002/ldr.652"
- Description: There is a growing commercialization of non-timber forest products (NTFPs) as a means of livelihood by rural communities throughout the developing world. This often occurs in the absence of any clear understanding of or guidelines regarding sustainable yields and ecological impacts, which may undermine the success of NTFP enterprises, especially from arid regions. This paper reports on the use of size class profiles and three quantitative indices to examine population profiles of five potentially useful tree species used as NTFPs in the semiarid lowveld of South Africa. We also contrast the population densities of the five tree species in 2003 with data from 1992. Low stem densities and population profiles indicated that three of the five species would preclude the establishment of NTFP enterprises based on their products. The other two species seem to have sufficient densities for some harvesting to take place, within an adaptive management framework. However, the longitudinal data indicated that the density of both these species had significantly declined over an eleven-year period, highlighting the need for appropriate management institutions. Additionally, the proportion of mature stems cut, and the degree of cutting per stem, had increased for all five species over the eleven years. The three quantitative indices of population stability were not correlated with one another, and hence provided a useful suite of measures sensitive to different aspects of size class profiles and their interpretation.
- Full Text:
- Date Issued: 2005
- Authors: Shackleton, Charlie M , Guthrie, G , Main, R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181324 , vital:43719 , xlink:href="https://doi.org/10.1002/ldr.652"
- Description: There is a growing commercialization of non-timber forest products (NTFPs) as a means of livelihood by rural communities throughout the developing world. This often occurs in the absence of any clear understanding of or guidelines regarding sustainable yields and ecological impacts, which may undermine the success of NTFP enterprises, especially from arid regions. This paper reports on the use of size class profiles and three quantitative indices to examine population profiles of five potentially useful tree species used as NTFPs in the semiarid lowveld of South Africa. We also contrast the population densities of the five tree species in 2003 with data from 1992. Low stem densities and population profiles indicated that three of the five species would preclude the establishment of NTFP enterprises based on their products. The other two species seem to have sufficient densities for some harvesting to take place, within an adaptive management framework. However, the longitudinal data indicated that the density of both these species had significantly declined over an eleven-year period, highlighting the need for appropriate management institutions. Additionally, the proportion of mature stems cut, and the degree of cutting per stem, had increased for all five species over the eleven years. The three quantitative indices of population stability were not correlated with one another, and hence provided a useful suite of measures sensitive to different aspects of size class profiles and their interpretation.
- Full Text:
- Date Issued: 2005
Modelling the sustainable harvest of Sclerocarya birrea subsp. caffra fruits in the South African lowveld
- Emanuel, P L, Shackleton, Charlie M, Baxter, Jeremy
- Authors: Emanuel, P L , Shackleton, Charlie M , Baxter, Jeremy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181312 , vital:43718 , xlink:href="https://doi.org/10.1016/j.foreco.2005.03.066"
- Description: Levels of commercialization, size class profile and fruit production of Sclerocarya birrea (marula) trees were studied in the Bushbuckridge region of South Africa. A stage-based population matrix model was used to estimate the sustainable yield for S. birrea fruit. The trees begin to bear fruit at an average size of 42.8 cm in circumference and this relates to an approximate age of 19 years. For a stable size class profile, the population growth rate, λ, was 1.1828758. The observed size class profile did not conform to the stable stage size class profile, obtained from the model. Thus, it was not possible to predict the state of the observed population. Using the model, it was estimated that 92% of fruit could be removed without impacting the current population profile. The management of other more destructive forms of S. birrea resource use (such as bark or firewood harvesting), however, do need to be monitored to limit negative impacts on the population that may reduce fruit availability for regeneration or cropping.
- Full Text:
- Date Issued: 2005
- Authors: Emanuel, P L , Shackleton, Charlie M , Baxter, Jeremy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181312 , vital:43718 , xlink:href="https://doi.org/10.1016/j.foreco.2005.03.066"
- Description: Levels of commercialization, size class profile and fruit production of Sclerocarya birrea (marula) trees were studied in the Bushbuckridge region of South Africa. A stage-based population matrix model was used to estimate the sustainable yield for S. birrea fruit. The trees begin to bear fruit at an average size of 42.8 cm in circumference and this relates to an approximate age of 19 years. For a stable size class profile, the population growth rate, λ, was 1.1828758. The observed size class profile did not conform to the stable stage size class profile, obtained from the model. Thus, it was not possible to predict the state of the observed population. Using the model, it was estimated that 92% of fruit could be removed without impacting the current population profile. The management of other more destructive forms of S. birrea resource use (such as bark or firewood harvesting), however, do need to be monitored to limit negative impacts on the population that may reduce fruit availability for regeneration or cropping.
- Full Text:
- Date Issued: 2005
Monetary valuation of livelihoods for understanding the composition and complexity of rural households
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181346 , vital:43721 , xlink:href="https://doi.org/10.1007/s10460-004-7233-0"
- Description: There is, at present, little precise understanding of the relative contributions of the various income streams used by impoverished rural households in southern Africa. The impact of household profiles on overall income also is not well understood. There is, therefore, little consideration of these factors in national economic accounting. This paper is an attempt to reduce this gap in knowledge by reflecting on the relative contribution of agro-pastoralism, secondary woodland resources, and formal and informal cash income streams to households in the semi-arid rural village of Thorndale, Limpopo Province, South Africa. In the absence of jobs and confronted with high migrant labor, households with open access to natural resources derived more benefits from land-based livelihoods than cash income streams (i.e., 57.5 % vs. 42.5 %). Total livelihood income was valued at US$2887 per household per annum. A significant correlation between monetary values derived from crops and formal wages was established, and it was found that households with high cash incomes tended to invest more in crop production. Over 80 of households were male-headed. Of these heads of household, more than 60 were long-term migrants to urban areas, leaving household decision-making to the women. The low literacy rates of women have deprived them of paid jobs outside the area and, therefore, have increased their dependence on crops (62%) and secondary woodlands resources (60%). This was further reflected in the proportion of households in which females were the main contributors of cash income (9.7%), or joint contributors with men (24.4%). Various positive correlations were established between the number of women per household and the three land-based livelihoods. This implied that women’s total control over such activities was mostly a result of the absence of men and not a typical phenomenon. In spite of this control, it was not positively reflected in the lives of majority of the women. Households differed in their participation in livelihood activities. Household size influenced the level of production and was positively correlated with the value of secondary woodland resources and crops. The study shows the interdependence of land-based livelihood sources and the impact of household features on production and consumption. Policies that focus on livelihood options need to recognize and accommodate associated household dynamics.
- Full Text:
- Date Issued: 2005
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181346 , vital:43721 , xlink:href="https://doi.org/10.1007/s10460-004-7233-0"
- Description: There is, at present, little precise understanding of the relative contributions of the various income streams used by impoverished rural households in southern Africa. The impact of household profiles on overall income also is not well understood. There is, therefore, little consideration of these factors in national economic accounting. This paper is an attempt to reduce this gap in knowledge by reflecting on the relative contribution of agro-pastoralism, secondary woodland resources, and formal and informal cash income streams to households in the semi-arid rural village of Thorndale, Limpopo Province, South Africa. In the absence of jobs and confronted with high migrant labor, households with open access to natural resources derived more benefits from land-based livelihoods than cash income streams (i.e., 57.5 % vs. 42.5 %). Total livelihood income was valued at US$2887 per household per annum. A significant correlation between monetary values derived from crops and formal wages was established, and it was found that households with high cash incomes tended to invest more in crop production. Over 80 of households were male-headed. Of these heads of household, more than 60 were long-term migrants to urban areas, leaving household decision-making to the women. The low literacy rates of women have deprived them of paid jobs outside the area and, therefore, have increased their dependence on crops (62%) and secondary woodlands resources (60%). This was further reflected in the proportion of households in which females were the main contributors of cash income (9.7%), or joint contributors with men (24.4%). Various positive correlations were established between the number of women per household and the three land-based livelihoods. This implied that women’s total control over such activities was mostly a result of the absence of men and not a typical phenomenon. In spite of this control, it was not positively reflected in the lives of majority of the women. Households differed in their participation in livelihood activities. Household size influenced the level of production and was positively correlated with the value of secondary woodland resources and crops. The study shows the interdependence of land-based livelihood sources and the impact of household features on production and consumption. Policies that focus on livelihood options need to recognize and accommodate associated household dynamics.
- Full Text:
- Date Issued: 2005
The contribution and direct-use value of livestock to rural livelihoods in the Sand River catchment, South Africa
- Shackleton, Charlie M, Shackleton, Sheona E, Netshiluvhi, T R, Mathabela, F R
- Authors: Shackleton, Charlie M , Shackleton, Sheona E , Netshiluvhi, T R , Mathabela, F R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181335 , vital:43720 , xlink:href="https://doi.org/10.2989/10220110509485870"
- Description: The productive functions of livestock ownership in communal areas are multipurpose in character, comprising a mix of stock types and a range of goods and services used. When all these multiple uses are accounted for, the cash and direct-use returns of livestock in communal areas can be comparable to commercial systems, although temporally and spatially variable. Yet previous work has generally excluded small stock from such analyses, as well as benefits and costs to non-owning households. This paper presents empirical results of a study in the Sand River catchment, assessing the benefits and costs accruing to owners and non-owners for both cattle and goats within a livelihoods analysis framework. Results indicate that cattle are used for a greater variety of goods and services than are goats. The savings value represented the most important function, followed by milk and then manure. Even if savings value was excluded, cattle ownership made a significant contribution to local livelihoods. Goats also provided a net positive benefit, represented largely by the savings value, followed by meat and cash sales. Non-owners also benefited through donations of manure, milk, draught and meat for free, or at a cheaper rate than alternatives. The majority of non-owners aspired to livestock ownership, although the risk of theft of animals was of growing concern. Averaged across the whole catchment, the net value of goods and services from livestock was just over R400 per hectare, with an annual return to capital of 36%. Cattle contributed the bulk of the value by virtue of their greater numbers and larger size, but on a per kilogramme basis goats provided higher value. Many of the goods and services obtained from livestock were not enumerated in regional or national economic statistics.
- Full Text:
- Date Issued: 2005
- Authors: Shackleton, Charlie M , Shackleton, Sheona E , Netshiluvhi, T R , Mathabela, F R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181335 , vital:43720 , xlink:href="https://doi.org/10.2989/10220110509485870"
- Description: The productive functions of livestock ownership in communal areas are multipurpose in character, comprising a mix of stock types and a range of goods and services used. When all these multiple uses are accounted for, the cash and direct-use returns of livestock in communal areas can be comparable to commercial systems, although temporally and spatially variable. Yet previous work has generally excluded small stock from such analyses, as well as benefits and costs to non-owning households. This paper presents empirical results of a study in the Sand River catchment, assessing the benefits and costs accruing to owners and non-owners for both cattle and goats within a livelihoods analysis framework. Results indicate that cattle are used for a greater variety of goods and services than are goats. The savings value represented the most important function, followed by milk and then manure. Even if savings value was excluded, cattle ownership made a significant contribution to local livelihoods. Goats also provided a net positive benefit, represented largely by the savings value, followed by meat and cash sales. Non-owners also benefited through donations of manure, milk, draught and meat for free, or at a cheaper rate than alternatives. The majority of non-owners aspired to livestock ownership, although the risk of theft of animals was of growing concern. Averaged across the whole catchment, the net value of goods and services from livestock was just over R400 per hectare, with an annual return to capital of 36%. Cattle contributed the bulk of the value by virtue of their greater numbers and larger size, but on a per kilogramme basis goats provided higher value. Many of the goods and services obtained from livestock were not enumerated in regional or national economic statistics.
- Full Text:
- Date Issued: 2005
Harvesting impacts on commonly used medicinal tree species (Catha edulis and Rapanea melanophloeos) under different land management regimes in the Mpumalanga Lowveld, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181379 , vital:43728 , xlink:href="https://doi.org/10.4102/koedoe.v47i2.77"
- Description: Harvesting of products from plants in the wild is widespread throughout southern Africa. Particularly important products are plant parts used in traditional medicine. However, the impacts of harvesting practices are rarely quantified, with as yet insufficient generic rules across species and life forms. This limits the predictive ability to monitor and manage the affected populations. This paper examines the harvesting impact on two popular woody medicinal species used throughout sub-Saharan Africa, namely Catha edulis (Vahl) Forssk. ex Endl. (bushman’s tea) and Rapanea melanophloeos (L.) Mez. (Cape beech). In both species, basal diameters, heights, and the number of size classes in the harvested populations were lower than in unharvested. Densities of harvested populations were higher in both species, including densities of young plants, but the frequency of individuals in larger size classes was lower. The populations of both species being harvested for medicinal products appeared to be withstanding the current levels of harvesting, but the population structure of C. edulis populations being harvested for poles on the roadside and near human settlements had been substantially altered. Despite the resilience of the two species to harvesting for medicinal products, loss of habitat or changes in land use pose a threat to a number of the assessed populations.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181379 , vital:43728 , xlink:href="https://doi.org/10.4102/koedoe.v47i2.77"
- Description: Harvesting of products from plants in the wild is widespread throughout southern Africa. Particularly important products are plant parts used in traditional medicine. However, the impacts of harvesting practices are rarely quantified, with as yet insufficient generic rules across species and life forms. This limits the predictive ability to monitor and manage the affected populations. This paper examines the harvesting impact on two popular woody medicinal species used throughout sub-Saharan Africa, namely Catha edulis (Vahl) Forssk. ex Endl. (bushman’s tea) and Rapanea melanophloeos (L.) Mez. (Cape beech). In both species, basal diameters, heights, and the number of size classes in the harvested populations were lower than in unharvested. Densities of harvested populations were higher in both species, including densities of young plants, but the frequency of individuals in larger size classes was lower. The populations of both species being harvested for medicinal products appeared to be withstanding the current levels of harvesting, but the population structure of C. edulis populations being harvested for poles on the roadside and near human settlements had been substantially altered. Despite the resilience of the two species to harvesting for medicinal products, loss of habitat or changes in land use pose a threat to a number of the assessed populations.
- Full Text:
- Date Issued: 2004
Market profiles and trade in medicinal plants in the Lowveld, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: Kruger National Park
- Language: English
- Type: Article
- Identifier: vital:6625 , http://hdl.handle.net/10962/d1006817
- Description: Rising demand for medicinal plants has led to increased pressure on wild plant populations. This, combined with shrinking habitats, means that many species in South Africa are now facing local extinction. In 1997, a study was initiated to determine the extent of trade in medicinal plants in the South African Lowveld (the low lying plains to the east of the Drakensberg escarpment), and to investigate socio-economic factors influencing trade and resource management. Trade was not as extensive in the Lowveld as in major urban markets such as Durban or the Witwatersrand (Johannesburg and surrounding towns), either in terms of the quantity, number or range of species sold, or the numbers of people relying on the trade for an income. In markets assessed in Mpumalanga Province, 176 species were identified (71% of the vernacular names encountered in the market place), representing 69 plant families. In Limpopo, 70 different species were identified (84% of the vernacular names encountered in the market place), representing 40 families. Imports were significant in Mpumalanga (33% of the plants on offer), mainly from Mozambique. A detrended correspondence analysis showed substantial differences between species traded in Mpumalanga and those sold in Limpopo. There was little variation in the species stocked by vendors in Mpumalanga, regardless of the season, the attributes of the seller, or whether business was carried out in urban or rural areas. In contrast, there was considerable variation in the stock inventories of the Limpopo traders. Despite the lower levels of local trade, increased harvesting pressure is being experienced regionally, to meet demand in metropolitan centres such as the Witwatersrand. This study showed considerable local variation and complexities in the harvesting and marketing of medicinal plants, with both a national and an international dimension. This dual spatial scale presents both opportunities and challenges in the management of these plants, which need to be addressed simultaneously, particularly with respect to research requirements and development of predictive models and capacity. Cooperation in conservation strategies and policies is required at regional, national and international levels, while ensuring that management initiatives take into account local market conditions and the socio-economic realities facing both consumers and those who depend on the trade for their livelihoods.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: Kruger National Park
- Language: English
- Type: Article
- Identifier: vital:6625 , http://hdl.handle.net/10962/d1006817
- Description: Rising demand for medicinal plants has led to increased pressure on wild plant populations. This, combined with shrinking habitats, means that many species in South Africa are now facing local extinction. In 1997, a study was initiated to determine the extent of trade in medicinal plants in the South African Lowveld (the low lying plains to the east of the Drakensberg escarpment), and to investigate socio-economic factors influencing trade and resource management. Trade was not as extensive in the Lowveld as in major urban markets such as Durban or the Witwatersrand (Johannesburg and surrounding towns), either in terms of the quantity, number or range of species sold, or the numbers of people relying on the trade for an income. In markets assessed in Mpumalanga Province, 176 species were identified (71% of the vernacular names encountered in the market place), representing 69 plant families. In Limpopo, 70 different species were identified (84% of the vernacular names encountered in the market place), representing 40 families. Imports were significant in Mpumalanga (33% of the plants on offer), mainly from Mozambique. A detrended correspondence analysis showed substantial differences between species traded in Mpumalanga and those sold in Limpopo. There was little variation in the species stocked by vendors in Mpumalanga, regardless of the season, the attributes of the seller, or whether business was carried out in urban or rural areas. In contrast, there was considerable variation in the stock inventories of the Limpopo traders. Despite the lower levels of local trade, increased harvesting pressure is being experienced regionally, to meet demand in metropolitan centres such as the Witwatersrand. This study showed considerable local variation and complexities in the harvesting and marketing of medicinal plants, with both a national and an international dimension. This dual spatial scale presents both opportunities and challenges in the management of these plants, which need to be addressed simultaneously, particularly with respect to research requirements and development of predictive models and capacity. Cooperation in conservation strategies and policies is required at regional, national and international levels, while ensuring that management initiatives take into account local market conditions and the socio-economic realities facing both consumers and those who depend on the trade for their livelihoods.
- Full Text:
- Date Issued: 2004
Socio-economic differentiation in the trade of wildlife species for traditional medicines in the Lowveld, South Africa: Implications for resource management initiatives
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M, Fairbanks, Dean H K
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M , Fairbanks, Dean H K
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183071 , vital:43909 , xlink:href="https://doi.org/10.1080/13504500409469832"
- Description: Surveys of trade in wildlife products utilised in traditional medicine were conducted between 1997 and 1999 on the western boundary of the Kruger National Park, South Africa. Although the extent of trade and numbers of people operating in this sector were lower than other regions of South Africa, this study again highlighted the value of indigenous wildlife products to subsistence economies. Apart from cultural diversity, socioeconomic differentiation occurred at a number of levels. (i) There were socio-economic differences between the traders and vendors. (ii) Gender differences were apparent, with women earning significantly less than men and having to undergo more social challenges in their operation in the market place. (iii) Operational differences were noted between the vendors and traders, as well as between the street and pension day vendors. (iv) Multidimensional Scaling (MDS) highlighted the socio-economic differentiation at the household level, emphasizing in particular one of the most vulnerable groups, the elderly. The potential influence of this socio-economic differentiation needs to be considered during the development of Community-Based Conservation programmes, if the dual aims of conserving biodiversity and improving the lives and livelihoods of those who traditionally rely on medicinal plants are to be met.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M , Fairbanks, Dean H K
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183071 , vital:43909 , xlink:href="https://doi.org/10.1080/13504500409469832"
- Description: Surveys of trade in wildlife products utilised in traditional medicine were conducted between 1997 and 1999 on the western boundary of the Kruger National Park, South Africa. Although the extent of trade and numbers of people operating in this sector were lower than other regions of South Africa, this study again highlighted the value of indigenous wildlife products to subsistence economies. Apart from cultural diversity, socioeconomic differentiation occurred at a number of levels. (i) There were socio-economic differences between the traders and vendors. (ii) Gender differences were apparent, with women earning significantly less than men and having to undergo more social challenges in their operation in the market place. (iii) Operational differences were noted between the vendors and traders, as well as between the street and pension day vendors. (iv) Multidimensional Scaling (MDS) highlighted the socio-economic differentiation at the household level, emphasizing in particular one of the most vulnerable groups, the elderly. The potential influence of this socio-economic differentiation needs to be considered during the development of Community-Based Conservation programmes, if the dual aims of conserving biodiversity and improving the lives and livelihoods of those who traditionally rely on medicinal plants are to be met.
- Full Text:
- Date Issued: 2004
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
The impact of commercial harvesting on Warburgia salutaris (‘pepper-bark tree’) in Mpumalanga, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
- Date Issued: 2004
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
- Date Issued: 2004
The importance of non-timber forest products in rural livelihood security and as safety nets: a review of evidence from South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6650 , http://hdl.handle.net/10962/d1007061
- Description: We review and synthesize recent South African work that examines the role and importance of non-timber forest products (NTFPs) in the daily lives of rural people in South Africa. The most commonly used such products are wild spinaches, fuelwood, wooden utensils edible fruits, grass hand-brushes, and twig hand-brushes, used by 85% or more of households. More than half the households investigated also make use of edible insects, wood for construction, bushmeat, wild honey and reeds for weaving. Individual households may exploit dozens of animal and plant species. The range in annual, direct-use values is large, from less than R1000 per household per year to over R12 000. The value to rural households is manifest through a daily net function which represents a cost saving to the families involved and to the state, as well as through an emergency net, which serves as an insurance in times of misfortune, such as drought, disease, and unexpected economic hardship. The emergency net function has hardly been quantified in South Africa and internationally. Ad hoc trade in NTFPs is a common emergency net, which in some instances evolves into a permanent way of life. Financial returns from trade are variable, depending on resource type and hours worked, but are typically low. Despite the small cash incomes from trade, they provide an important contribution that complement the diverse livelihood strategies within a household, especially for the poorer sectors of rural society. Moreover, there are non-financial benefits of NTFP trade that are commonly overlooked.
- Full Text:
- Date Issued: 2004
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6650 , http://hdl.handle.net/10962/d1007061
- Description: We review and synthesize recent South African work that examines the role and importance of non-timber forest products (NTFPs) in the daily lives of rural people in South Africa. The most commonly used such products are wild spinaches, fuelwood, wooden utensils edible fruits, grass hand-brushes, and twig hand-brushes, used by 85% or more of households. More than half the households investigated also make use of edible insects, wood for construction, bushmeat, wild honey and reeds for weaving. Individual households may exploit dozens of animal and plant species. The range in annual, direct-use values is large, from less than R1000 per household per year to over R12 000. The value to rural households is manifest through a daily net function which represents a cost saving to the families involved and to the state, as well as through an emergency net, which serves as an insurance in times of misfortune, such as drought, disease, and unexpected economic hardship. The emergency net function has hardly been quantified in South Africa and internationally. Ad hoc trade in NTFPs is a common emergency net, which in some instances evolves into a permanent way of life. Financial returns from trade are variable, depending on resource type and hours worked, but are typically low. Despite the small cash incomes from trade, they provide an important contribution that complement the diverse livelihood strategies within a household, especially for the poorer sectors of rural society. Moreover, there are non-financial benefits of NTFP trade that are commonly overlooked.
- Full Text:
- Date Issued: 2004
A proposed prioritization system for the management of invasive alien plants in South Africa
- Robertson, Mark P, Villet, Martin H, Fairbanks, Dean H K, Henderson, L, Higgins, Simon I, Hoffmann, John H, Le Maitre, David C, Palmer, Anthony R, Riggs, I, Shackleton, Charlie M, Zimmermann, Helmuth G
- Authors: Robertson, Mark P , Villet, Martin H , Fairbanks, Dean H K , Henderson, L , Higgins, Simon I , Hoffmann, John H , Le Maitre, David C , Palmer, Anthony R , Riggs, I , Shackleton, Charlie M , Zimmermann, Helmuth G
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6911 , http://hdl.handle.net/10962/d1011872
- Description: Every country has weed species whose presence conflicts in some way with human management objectives and needs. Resources for research and control are limited, so priority should be given to species that are the biggest problem. The prioritization system described in this article was designed to assess objectively research and control priorities of invasive alien plants at a national scale in South Africa. The evaluation consists of seventeen criteria, grouped into five modules, that assess invasiveness, spatial characteristics, potential impact, potential for control, and conflicts of interest for each plant species under consideration. Total prioritization scores, calculated from criterion and module scores, were used to assess a species' priority. Prioritization scores were calculated by combining independent assessments provided by several experts, thus increasing the reliability of the rankings. The total confidence score, a separate index, indicates the reliability and availability of data used to make an assessment. Candidate species for evaluation were identified and assessed by several experts using the prioritization system. The final ranking was made by combining two separate indices, the total prioritization score and the total confidence score. This approach integrates the plant's perceived priority with an index of data reliability. Of the 61 species assessed, those with the highest ranks (Lantana camara, Chromolaena odorata and Opuntia ficus-indica) had high prioritization and high confidence scores, and are thus of most concern. Those species with the lowest ranks, for example, Harrisia martinii, Opuntia spinulifera and Opuntia exaltata, had low prioritization scores and high confidence scores, and thus are of least concern. Our approach to ranking weeds offers several advantages over existing systems because it is designed for multiple assessors based on the Delphi decision-making technique, the criteria contribute equally to the total score, and the system can accommodate incomplete data on a species. Although the choice of criteria may be criticized and the system has certain limitations, it appears to have delivered credible results.
- Full Text:
- Date Issued: 2003
- Authors: Robertson, Mark P , Villet, Martin H , Fairbanks, Dean H K , Henderson, L , Higgins, Simon I , Hoffmann, John H , Le Maitre, David C , Palmer, Anthony R , Riggs, I , Shackleton, Charlie M , Zimmermann, Helmuth G
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6911 , http://hdl.handle.net/10962/d1011872
- Description: Every country has weed species whose presence conflicts in some way with human management objectives and needs. Resources for research and control are limited, so priority should be given to species that are the biggest problem. The prioritization system described in this article was designed to assess objectively research and control priorities of invasive alien plants at a national scale in South Africa. The evaluation consists of seventeen criteria, grouped into five modules, that assess invasiveness, spatial characteristics, potential impact, potential for control, and conflicts of interest for each plant species under consideration. Total prioritization scores, calculated from criterion and module scores, were used to assess a species' priority. Prioritization scores were calculated by combining independent assessments provided by several experts, thus increasing the reliability of the rankings. The total confidence score, a separate index, indicates the reliability and availability of data used to make an assessment. Candidate species for evaluation were identified and assessed by several experts using the prioritization system. The final ranking was made by combining two separate indices, the total prioritization score and the total confidence score. This approach integrates the plant's perceived priority with an index of data reliability. Of the 61 species assessed, those with the highest ranks (Lantana camara, Chromolaena odorata and Opuntia ficus-indica) had high prioritization and high confidence scores, and are thus of most concern. Those species with the lowest ranks, for example, Harrisia martinii, Opuntia spinulifera and Opuntia exaltata, had low prioritization scores and high confidence scores, and thus are of least concern. Our approach to ranking weeds offers several advantages over existing systems because it is designed for multiple assessors based on the Delphi decision-making technique, the criteria contribute equally to the total score, and the system can accommodate incomplete data on a species. Although the choice of criteria may be criticized and the system has certain limitations, it appears to have delivered credible results.
- Full Text:
- Date Issued: 2003
Direct-use value of smallholder crop production in a semi-arid rural South African 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: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181595 , vital:43750 , xlink:href="https://doi.org/10.1016/S0308-521X(02)00124-5"
- Description: The monetary value of natural resources used by rural communities for subsistence is important when addressing issues affecting the livelihoods of impoverished rural households. There is therefore the need to attribute monetary values to non-marketed products from smallholder production systems in order to reliably account for resource availability and usage to further sound policy decisions. The objective of this paper is to present an empirical analysis of the direct-use and traded values of crop production by households, and to discuss the implications for policy development. The study was undertaken in combination with an evaluation of other livelihood sectors in Thorndale, a semi-arid rural village in the Limpopo province of South Africa. The net direct-use value of crops was estimated at $443.4 per household per annum across the village. Maize (Zea mays), watermelon (Citrullus, vulgaris), peanuts (Arachis hypogaea) and common beans (Phaseolus vulgaris) contributed over 90% to the total direct-use value of crops. Maize alone contributed 40% of this value per household at an estimated $652/ha. Marketing of resources was not a common practice, limited to only maize and peanuts. Farming was basically a rain-fed–mixed cropping system with low production inputs. Farmer support services, human capital development and tenure security were major areas identified for policy development.
- Full Text:
- Date Issued: 2003
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181595 , vital:43750 , xlink:href="https://doi.org/10.1016/S0308-521X(02)00124-5"
- Description: The monetary value of natural resources used by rural communities for subsistence is important when addressing issues affecting the livelihoods of impoverished rural households. There is therefore the need to attribute monetary values to non-marketed products from smallholder production systems in order to reliably account for resource availability and usage to further sound policy decisions. The objective of this paper is to present an empirical analysis of the direct-use and traded values of crop production by households, and to discuss the implications for policy development. The study was undertaken in combination with an evaluation of other livelihood sectors in Thorndale, a semi-arid rural village in the Limpopo province of South Africa. The net direct-use value of crops was estimated at $443.4 per household per annum across the village. Maize (Zea mays), watermelon (Citrullus, vulgaris), peanuts (Arachis hypogaea) and common beans (Phaseolus vulgaris) contributed over 90% to the total direct-use value of crops. Maize alone contributed 40% of this value per household at an estimated $652/ha. Marketing of resources was not a common practice, limited to only maize and peanuts. Farming was basically a rain-fed–mixed cropping system with low production inputs. Farmer support services, human capital development and tenure security were major areas identified for policy development.
- Full Text:
- Date Issued: 2003
Fuelwood availability and use in the Richtersveld National Park, South Africa
- Shackleton, Charlie M, Guthrie, G, Keirungi, J, Stewart, J
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
Host-preference and density of woodrose-forming mistletoes (Loranthaceae) on savanna vegetation, South Africa
- Dzerefos, Cathy M, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dzerefos, Cathy M , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181487 , vital:43738 , xlink:href="https://doi.org/10.1023/A:1023991514968"
- Description: In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. and Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high, more than 660 or low , less than 660 mm year−1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.
- Full Text:
- Date Issued: 2003
- Authors: Dzerefos, Cathy M , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181487 , vital:43738 , xlink:href="https://doi.org/10.1023/A:1023991514968"
- Description: In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. and Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high, more than 660 or low , less than 660 mm year−1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.
- Full Text:
- Date Issued: 2003
Productivity and abundance of Sclerocarya birrea subsp. caffra in and around rural settlements and protected areas of the Bushbuckridge lowveld, South Africa
- Shackleton, Charlie M, Botha, Jenny, Emanuel, P L
- Authors: Shackleton, Charlie M , Botha, Jenny , Emanuel, P L
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181607 , vital:43751 , xlink:href="https://doi.org/10.1080/14728028.2003.9752459"
- Description: Sclerocarya birrea (A. Rich.) Hochst, subsp. caffra (Sond.) Kokwaro is a common species throughout the semi-arid savannas of southern Africa, and is sought after by rural communities. It is frequently maintained in homesteads and fields in an agroforestry situation. It has also been identified by a number of international and national institutes as a key species for domestication and commercialisation. Yet, the sustainability of the resource and local user knowledge and practices have not been considered. This study reports on the abundance and productivity of S. birrea in four rural villages and neighbouring protected areas in the Bushbuckridge lowveld of the Limpopo Province, South Africa, where its common name is marula. The density of marula stems was measured in homestead plots, arable fields and the surrounding communal rangelands of each village. Fruit production was assessed by regular counting of fruit fall from marked trees of known size. Within the villages, fruit production was monitored via local community groups. Additional monitoring of fruiting was conducted on marked trees within local protected areas. The proportion of households planting or nurturing marula trees was determined through interviews with a stratified random sample of households. The density of marula trees was significantly higher in protected areas than the neighbouring communal lands, fields or homesteads. However, the majority of trees in protected areas were small, while those in homesteads were large and mature. Density of adult fruit-bearing female trees, was similar between the protected areas and homesteads, but less in fields and communal lands. S. birrea trees were maintained in 79 % of homesteads and 58 % of fields. Mean fruit yield per tree was significantly higher from village trees (less than 17 000 fruits) than protected area trees (more than 3 500 fruits), even after accounting for differences in tree size. The fresh mass of individual fruits was also greater on village trees than on trees in protected areas. Both these characteristics suggest some degree of historical selection of the trees in the homesteads and fields. There was a positive relationship between tree size and number of fruits produced.
- Full Text:
- Date Issued: 2003
- Authors: Shackleton, Charlie M , Botha, Jenny , Emanuel, P L
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181607 , vital:43751 , xlink:href="https://doi.org/10.1080/14728028.2003.9752459"
- Description: Sclerocarya birrea (A. Rich.) Hochst, subsp. caffra (Sond.) Kokwaro is a common species throughout the semi-arid savannas of southern Africa, and is sought after by rural communities. It is frequently maintained in homesteads and fields in an agroforestry situation. It has also been identified by a number of international and national institutes as a key species for domestication and commercialisation. Yet, the sustainability of the resource and local user knowledge and practices have not been considered. This study reports on the abundance and productivity of S. birrea in four rural villages and neighbouring protected areas in the Bushbuckridge lowveld of the Limpopo Province, South Africa, where its common name is marula. The density of marula stems was measured in homestead plots, arable fields and the surrounding communal rangelands of each village. Fruit production was assessed by regular counting of fruit fall from marked trees of known size. Within the villages, fruit production was monitored via local community groups. Additional monitoring of fruiting was conducted on marked trees within local protected areas. The proportion of households planting or nurturing marula trees was determined through interviews with a stratified random sample of households. The density of marula trees was significantly higher in protected areas than the neighbouring communal lands, fields or homesteads. However, the majority of trees in protected areas were small, while those in homesteads were large and mature. Density of adult fruit-bearing female trees, was similar between the protected areas and homesteads, but less in fields and communal lands. S. birrea trees were maintained in 79 % of homesteads and 58 % of fields. Mean fruit yield per tree was significantly higher from village trees (less than 17 000 fruits) than protected area trees (more than 3 500 fruits), even after accounting for differences in tree size. The fresh mass of individual fruits was also greater on village trees than on trees in protected areas. Both these characteristics suggest some degree of historical selection of the trees in the homesteads and fields. There was a positive relationship between tree size and number of fruits produced.
- Full Text:
- Date Issued: 2003
The prevalence of use and value of wild edible herbs in South Africa
- Authors: Shackleton, Charlie M
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6652 , http://hdl.handle.net/10962/d1007063
- Description: The prevalence of use and commercial value of wild edible herbs in South Africa is examined from four recent quantitative studies at eight different sites. The use of wild edible herbs was widespread in rural communities, with over 90% of households using them in all but one sample site. Mean frequency of use in season was generally between two and five times per week, with a mean of four times across all sites. But many households consume them daily. Use in winter was less than in summer. The mass of wild edible herbs consumed ranged from 12 kg to over 130 kg per household per year. Local (farm-gate) prices ranged from R2.65 to R72 per kilogram, but were generally between R30 and R40 per kg. Direct-use value to consuming households ranged from R85 to almost R5000 across the eight sites, with a mean of R1020 per user household per year. Although harvesting of wild herbs takes time, the high gross direct-use value represents a considerable saving on having to purchase commercial alternatives. Key species differ from place to place both in availability and use, and include both indigenous and exotic species. Commonly used genera include Amaranthus, Bidens, Chenopodium, Cleome, Corchorus, and Momordica. The use, value and trade in wild edible herbs currently receives no recognition in land and agrarian reform policies. It is imperative that this be addressed, and the relationships between rural livelihoods, use of wild edible herbs, food security, and land and resource tenure be clarified, and debated within the policy forums around different models for, and delivery of, agrarian reform and rural development.
- Full Text:
- Date Issued: 2003
- Authors: Shackleton, Charlie M
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6652 , http://hdl.handle.net/10962/d1007063
- Description: The prevalence of use and commercial value of wild edible herbs in South Africa is examined from four recent quantitative studies at eight different sites. The use of wild edible herbs was widespread in rural communities, with over 90% of households using them in all but one sample site. Mean frequency of use in season was generally between two and five times per week, with a mean of four times across all sites. But many households consume them daily. Use in winter was less than in summer. The mass of wild edible herbs consumed ranged from 12 kg to over 130 kg per household per year. Local (farm-gate) prices ranged from R2.65 to R72 per kilogram, but were generally between R30 and R40 per kg. Direct-use value to consuming households ranged from R85 to almost R5000 across the eight sites, with a mean of R1020 per user household per year. Although harvesting of wild herbs takes time, the high gross direct-use value represents a considerable saving on having to purchase commercial alternatives. Key species differ from place to place both in availability and use, and include both indigenous and exotic species. Commonly used genera include Amaranthus, Bidens, Chenopodium, Cleome, Corchorus, and Momordica. The use, value and trade in wild edible herbs currently receives no recognition in land and agrarian reform policies. It is imperative that this be addressed, and the relationships between rural livelihoods, use of wild edible herbs, food security, and land and resource tenure be clarified, and debated within the policy forums around different models for, and delivery of, agrarian reform and rural development.
- Full Text:
- Date Issued: 2003
A comparison of anthropogenic and elephant disturbance on Acacia xanthophloea (fever tree) populations in the Lowveld, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181629 , vital:43753 , xlink:href="https://doi.org/10.4102/koedoe.v45i1.10"
- Description: Acacia xanthophloea (the ‘fever tree’) is a popular medicinal species that is traded widely in South Africa. Although it occurs throughout southern Africa, there is increasing pressure on its riverine and marshy habitats. This study compares the impact of harvesting on an A. xanthophloea population located on private land near Komatipoort, Mpumalanga, with two protected populations situated within the Kruger National Park. The densities of the harvested and protected populations were similar (84±8 trees/ha and 85±20 trees/ha, respectively). There were fluctuations in the quotients between frequencies of trees in successive diameter classes, which is common in savanna where high levels of fire, mega-herbivore and anthropogenic disturbance are experienced. The extent of stem damage (stripping of bark and breakage) by elephants in the protected area was significantly higher than the extent of harvesting on private land, although the degree of damage was relatively low, with only 7 % of the populations having been damaged at rates >26 %. The degree of harvesting on private land was relatively low, with the majority of trees having been harvested at rates of less than 10 % of the stem below 2 m. Despite this, ringbarking had occurred (4 %). The basal diameters and heights were significantly lower in the protected population than in the harvested one, suggesting that over time elephant impact was the more severe disturbance. Acacia xanthophloea exhibited high resilience to disturbance, with all the elephant damaged trees and harvested individuals surviving. However, the mean bark thickness measured in local markets (6.3±1.4 mm) was significantly lower than that measured in either the harvested (12.4±1.0 mm) or the KNP (10.3±0.8 mm) populations. As harvesters tend to select the largest individuals in a population to maximise their financial returns, this could mean that smaller individuals are being harvested, and/or bark is not being given sufficient time to grow back after harvesting. Acacia xanthophloea outside protected areas thus need to be monitored and the management improved, preferably in conjunction with the resource users. In addition, traditional healers, those selling medicinal plants and other members of the community need to continue to be encouraged to cultivate this fast growing species.
- Full Text:
- Date Issued: 2002
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181629 , vital:43753 , xlink:href="https://doi.org/10.4102/koedoe.v45i1.10"
- Description: Acacia xanthophloea (the ‘fever tree’) is a popular medicinal species that is traded widely in South Africa. Although it occurs throughout southern Africa, there is increasing pressure on its riverine and marshy habitats. This study compares the impact of harvesting on an A. xanthophloea population located on private land near Komatipoort, Mpumalanga, with two protected populations situated within the Kruger National Park. The densities of the harvested and protected populations were similar (84±8 trees/ha and 85±20 trees/ha, respectively). There were fluctuations in the quotients between frequencies of trees in successive diameter classes, which is common in savanna where high levels of fire, mega-herbivore and anthropogenic disturbance are experienced. The extent of stem damage (stripping of bark and breakage) by elephants in the protected area was significantly higher than the extent of harvesting on private land, although the degree of damage was relatively low, with only 7 % of the populations having been damaged at rates >26 %. The degree of harvesting on private land was relatively low, with the majority of trees having been harvested at rates of less than 10 % of the stem below 2 m. Despite this, ringbarking had occurred (4 %). The basal diameters and heights were significantly lower in the protected population than in the harvested one, suggesting that over time elephant impact was the more severe disturbance. Acacia xanthophloea exhibited high resilience to disturbance, with all the elephant damaged trees and harvested individuals surviving. However, the mean bark thickness measured in local markets (6.3±1.4 mm) was significantly lower than that measured in either the harvested (12.4±1.0 mm) or the KNP (10.3±0.8 mm) populations. As harvesters tend to select the largest individuals in a population to maximise their financial returns, this could mean that smaller individuals are being harvested, and/or bark is not being given sufficient time to grow back after harvesting. Acacia xanthophloea outside protected areas thus need to be monitored and the management improved, preferably in conjunction with the resource users. In addition, traditional healers, those selling medicinal plants and other members of the community need to continue to be encouraged to cultivate this fast growing species.
- Full Text:
- Date Issued: 2002
Fuel wood use in South Africa: Where to in the 21st Century?
- Williams, Anthony, Shackleton, Charlie M
- Authors: Williams, Anthony , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183026 , vital:43905 , xlink:href="https://doi.org/10.1080/20702620.2002.10434611"
- Description: South Africa is well known for the dichotomous nature of its economy, with its juxtaposed first and third world characteristics, perhaps nowhere more starkly evident than in the energy sector. South Africa produces and consumes over 60% of the total electrical energy on the African continent, and is ranked twelfth in the world in terms of carbon emissions (EIA, 2002). Yet the majority of the South African population does not have access to electricity, and despite the enormous strides taken since 1994 to increase household access to electricity (NER, 2001), newly electrified households, more often than not, cannot afford the appliances nor the monthly costs required to significantly improve their quality of life (White et al., 1997). Thus, most rural and many peri-urban households continue to use fuelwood as their primary energy source (Griffin et al., 1992; Dyer, 1996; Kotze, 1996; Williams et al., 1996). Fuelwood use presents both opportunities and risks.
- Full Text:
- Date Issued: 2002
- Authors: Williams, Anthony , Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183026 , vital:43905 , xlink:href="https://doi.org/10.1080/20702620.2002.10434611"
- Description: South Africa is well known for the dichotomous nature of its economy, with its juxtaposed first and third world characteristics, perhaps nowhere more starkly evident than in the energy sector. South Africa produces and consumes over 60% of the total electrical energy on the African continent, and is ranked twelfth in the world in terms of carbon emissions (EIA, 2002). Yet the majority of the South African population does not have access to electricity, and despite the enormous strides taken since 1994 to increase household access to electricity (NER, 2001), newly electrified households, more often than not, cannot afford the appliances nor the monthly costs required to significantly improve their quality of life (White et al., 1997). Thus, most rural and many peri-urban households continue to use fuelwood as their primary energy source (Griffin et al., 1992; Dyer, 1996; Kotze, 1996; Williams et al., 1996). Fuelwood use presents both opportunities and risks.
- Full Text:
- Date Issued: 2002
Growth and fruit production of Sclerocarya birrea in the South African lowveld
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181618 , vital:43752 , xlink:href="https://doi.org/10.1023/A:1020579213024"
- Description: Sclerocarya birrea (A.Rich.) Hochst. subsp. caffra (Sond.) Kokwaro. is a common species throughout the semiarid, deciduous savannas of much of sub-Saharan Africa. It is a favoured species and is frequently maintained in homestead plots and arable fields in an agroforestry situation. Although the abundance and popularity of this species has led to several initiatives to commercialise a number of marula products, the sustainability of the resource base with respect to fruit production has not been considered. This paper reports on a field experiment that monitored growth rates and fruit production of a sample of adult trees from several wild populations. Mean fruit production was 36.8 kg per tree in the first year, and negligible in the second. This was considerably less than previous estimates, which were based largely on small samples or anecdotal reports. The maximum recorded yield was 416.6 kg per tree. Fruit production was positively related to the size of the tree. Growth rates of adult trees were slow. There was a strong positive relationship between mean annual diameter increment and stem diameter. The slow growth rates and low fruit yields indicate that more attention is required regarding the sustainability of there source and its ability to provide sufficient fruit for the growing subsistence and commercial demand at both local and national scales.
- Full Text:
- Date Issued: 2002
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181618 , vital:43752 , xlink:href="https://doi.org/10.1023/A:1020579213024"
- Description: Sclerocarya birrea (A.Rich.) Hochst. subsp. caffra (Sond.) Kokwaro. is a common species throughout the semiarid, deciduous savannas of much of sub-Saharan Africa. It is a favoured species and is frequently maintained in homestead plots and arable fields in an agroforestry situation. Although the abundance and popularity of this species has led to several initiatives to commercialise a number of marula products, the sustainability of the resource base with respect to fruit production has not been considered. This paper reports on a field experiment that monitored growth rates and fruit production of a sample of adult trees from several wild populations. Mean fruit production was 36.8 kg per tree in the first year, and negligible in the second. This was considerably less than previous estimates, which were based largely on small samples or anecdotal reports. The maximum recorded yield was 416.6 kg per tree. Fruit production was positively related to the size of the tree. Growth rates of adult trees were slow. There was a strong positive relationship between mean annual diameter increment and stem diameter. The slow growth rates and low fruit yields indicate that more attention is required regarding the sustainability of there source and its ability to provide sufficient fruit for the growing subsistence and commercial demand at both local and national scales.
- Full Text:
- Date Issued: 2002
Growth patterns of Pterocarpus angolensis in savannas of the South African lowveld
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182373 , vital:43824 , xlink:href="https://doi.org/10.1016/S0378-1127(01)00676-4"
- Description: Pterocarpus angolensis D.C. is one of the most valuable indigenous timber species on the African continent south of the equator. Because of its high value, it is actively sought after in a number of countries, and wild populations are diminishing. However, attempts at artificial germination and growth trials have yielded poor results, thus, emphasis needs to be placed on sustainable management of existing populations. Success of in situ management will be enhanced if based on reliable data and knowledge regarding the growth patterns of this species within specific localities and countries. Such comprehensive data are lacking for several countries, including South Africa. This paper presents empirical data on a number of studies investigating the growth patterns of P. angolensis in the central lowveld savannas of South Africa, including phenology, annual diameter increment, size class structure, size of reproductive maturity, and morphometric relationships. The size class profile indicated that there was adequate recruitment of P. angolensis, but with constricted through growth from the suffrutex stage to the sapling stage. A small proportion of individuals attained reproductive maturity at 8 cm diameter, but most were bigger. All stems were reproductively mature by 26 cm diameter. This is below the minimum size for harvesting which is dictated by the need for a well developed heartwood. Annual growth was strongly related to stem size and rainfall during the growing season. Basal area increment of small stems was approximately four times greater than mature stems, and declined with increasing stem size. Over the 6-year-period and across all stem sizes, mean diameter increment was 4.5 mm per year. This rate is towards the lower end of the range of reported growth rates from other countries, and poses particular challenges for the sustainable management of this species in South African savannas.
- Full Text:
- Date Issued: 2002
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182373 , vital:43824 , xlink:href="https://doi.org/10.1016/S0378-1127(01)00676-4"
- Description: Pterocarpus angolensis D.C. is one of the most valuable indigenous timber species on the African continent south of the equator. Because of its high value, it is actively sought after in a number of countries, and wild populations are diminishing. However, attempts at artificial germination and growth trials have yielded poor results, thus, emphasis needs to be placed on sustainable management of existing populations. Success of in situ management will be enhanced if based on reliable data and knowledge regarding the growth patterns of this species within specific localities and countries. Such comprehensive data are lacking for several countries, including South Africa. This paper presents empirical data on a number of studies investigating the growth patterns of P. angolensis in the central lowveld savannas of South Africa, including phenology, annual diameter increment, size class structure, size of reproductive maturity, and morphometric relationships. The size class profile indicated that there was adequate recruitment of P. angolensis, but with constricted through growth from the suffrutex stage to the sapling stage. A small proportion of individuals attained reproductive maturity at 8 cm diameter, but most were bigger. All stems were reproductively mature by 26 cm diameter. This is below the minimum size for harvesting which is dictated by the need for a well developed heartwood. Annual growth was strongly related to stem size and rainfall during the growing season. Basal area increment of small stems was approximately four times greater than mature stems, and declined with increasing stem size. Over the 6-year-period and across all stem sizes, mean diameter increment was 4.5 mm per year. This rate is towards the lower end of the range of reported growth rates from other countries, and poses particular challenges for the sustainable management of this species in South African savannas.
- Full Text:
- Date Issued: 2002