Specialty Grand Challenges in Urban Agriculture: Ecological and Social Approaches to Sustainability Transformations
- Zimmerer, Karl S, Bell, Martha G, Chirisa, Innocent, Duvall, Chris S, Egerer, Monika, Hung, Po-Yi, Lerner, Amy M, Shackleton, Charlie M, Ward, James David, Yacamán Ochoa, Carolina
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
- Date Issued: 2021
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
- Date Issued: 2021
Impacts of gum-resin harvest and Lantana camara invasion on the population structure and dynamics of Boswellia serrata in the Western Ghats, India
- Soumya, Kori V, Shackleton, Charlie M, Setty, Siddappa R
- Authors: Soumya, Kori V , Shackleton, Charlie M , Setty, Siddappa R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177549 , vital:42832 , https://doi.org/10.1016/j.foreco.2019.117618
- Description: Assessing the effects of harvesting on the population dynamics of important non-timber forest products (NTFPs) species is important for informing species conservation options, guiding sustainable harvesting practices and offtake and supporting local livelihoods. However, harvesting is rarely the only pressure on NTFP populations, and it is vital that the effects of interactive pressures be considered. This applies to Boswellia serrata, an NTFP tree species which is widely harvested for gum-resin used in religious practices. However, in many settings populations are in decline, presumably due to heavy harvesting, but other factors may play a role, such as altered fire regimes and invasive species. Here we report on the effects of harvesting and invasion by Lantana camara on B. serrata populations in three protected areas in the Western Ghats biodiversity hotspot in southern India. We considered tree and juvenile density, size class distribution, and growth, mortality, and recruitment rates in harvested and unharvested populations over two years.
- Full Text:
- Date Issued: 2019
- Authors: Soumya, Kori V , Shackleton, Charlie M , Setty, Siddappa R
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177549 , vital:42832 , https://doi.org/10.1016/j.foreco.2019.117618
- Description: Assessing the effects of harvesting on the population dynamics of important non-timber forest products (NTFPs) species is important for informing species conservation options, guiding sustainable harvesting practices and offtake and supporting local livelihoods. However, harvesting is rarely the only pressure on NTFP populations, and it is vital that the effects of interactive pressures be considered. This applies to Boswellia serrata, an NTFP tree species which is widely harvested for gum-resin used in religious practices. However, in many settings populations are in decline, presumably due to heavy harvesting, but other factors may play a role, such as altered fire regimes and invasive species. Here we report on the effects of harvesting and invasion by Lantana camara on B. serrata populations in three protected areas in the Western Ghats biodiversity hotspot in southern India. We considered tree and juvenile density, size class distribution, and growth, mortality, and recruitment rates in harvested and unharvested populations over two years.
- Full Text:
- Date Issued: 2019
Knowledge and knowledge sources on the importance of fruits for nutritional security are unaffected by deforestation status in Cameroon
- Ijang, T N P, Shackleton, Charlie M, Degrande, A
- Authors: Ijang, T N P , Shackleton, Charlie M , Degrande, A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177454 , vital:42823 , DOI: 10.17660/th2019/74.6.2
- Description: The Congo basin forest is experiencing increasing rate of deforestation, and is prone to inconsistent food supply and sporadic food shortages with corresponding high levels of malnutrition. Maintenance or planting of fruit trees can help mitigate deforestation while supplying fruits for home consumption. However, data on rates of fruit consumption are lacking for many developing countries, including Cameroon.
- Full Text:
- Date Issued: 2019
- Authors: Ijang, T N P , Shackleton, Charlie M , Degrande, A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177454 , vital:42823 , DOI: 10.17660/th2019/74.6.2
- Description: The Congo basin forest is experiencing increasing rate of deforestation, and is prone to inconsistent food supply and sporadic food shortages with corresponding high levels of malnutrition. Maintenance or planting of fruit trees can help mitigate deforestation while supplying fruits for home consumption. However, data on rates of fruit consumption are lacking for many developing countries, including Cameroon.
- Full Text:
- Date Issued: 2019
Do indigenous street trees promote more biodiversity than alien ones? evidence using mistletoes and birds in South Africa
- Authors: Shackleton, Charlie M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64663 , vital:28587 , http://www.doi:10.3390/f7070134
- Description: Trees in urban landscapes provide a range of ecosystem services, including habitat, refugia,food, and corridors for other fauna and flora. However, there is some debate whether the richness and abundance of other biodiversity supported is influenced by the provenance of trees, i.e., native or non-native. This study assessed the presence of mistletoes and birds (and nests) in 1261 street trees. There were marked differences between native and non-native street trees, with the former having a significantly higher prevalence of birds (and nests) and supporting more species and in greater densities, whilst the latter supported a higher prevalence of mistletoes. Additionally, for birds, the proximity to green space, tree size and species were also important, whilst for mistletoes, the proximity to green space, slope aspect, and tree species were significant. Preference ratios indicated that some tree species had a higher than random occurrence of birds or mistletoes, whilst others had a low abundance. The indigenous tree species, Acacia karroo Hayne was the only reasonably abundant street tree species that was important for birds, nests, and mistletoes. At the street scale, there was a positive relationship between street tree species richness and bird species richness. These results emphasise the importance of selecting appropriate tree species if biodiversity conservation is a core outcome.
- Full Text:
- Date Issued: 2016
- Authors: Shackleton, Charlie M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64663 , vital:28587 , http://www.doi:10.3390/f7070134
- Description: Trees in urban landscapes provide a range of ecosystem services, including habitat, refugia,food, and corridors for other fauna and flora. However, there is some debate whether the richness and abundance of other biodiversity supported is influenced by the provenance of trees, i.e., native or non-native. This study assessed the presence of mistletoes and birds (and nests) in 1261 street trees. There were marked differences between native and non-native street trees, with the former having a significantly higher prevalence of birds (and nests) and supporting more species and in greater densities, whilst the latter supported a higher prevalence of mistletoes. Additionally, for birds, the proximity to green space, tree size and species were also important, whilst for mistletoes, the proximity to green space, slope aspect, and tree species were significant. Preference ratios indicated that some tree species had a higher than random occurrence of birds or mistletoes, whilst others had a low abundance. The indigenous tree species, Acacia karroo Hayne was the only reasonably abundant street tree species that was important for birds, nests, and mistletoes. At the street scale, there was a positive relationship between street tree species richness and bird species richness. These results emphasise the importance of selecting appropriate tree species if biodiversity conservation is a core outcome.
- Full Text:
- Date Issued: 2016
Quantity and significance of wild meat off-take by a rural community in the Eastern Cape, South Africa
- Kaschula, Sarah A H, Shackleton, Charlie M
- Authors: Kaschula, Sarah A H , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6638 , http://hdl.handle.net/10962/d1006864
- Description: When compared to tropical forest zones in west and central Africa, off-take of wild meat from savannah and grassland biomes by local rural communities has not been well assessed. This case study of wild meat collection activities within a rural community in the Mount Frere region of the Eastern Cape (South Africa) uses last-catch records derived from 50 wild meat gatherers to calculate average off-take of taxa, species and fresh mass of wild meat per collection event. When per-event off take is overlaid onto household hunting frequency data, annual off-take would be 268.6 kg km−2 yr−1 or 3 kg person−1 yr−1 presuming constant off-take over an annual period. Monetary value of off-take would be South African R 307 (US$ 39) per household annually. For some species, off-take weight per km2 shows similar values to data from tropical forest zones, but high human population densities tend to dilute off-takes to less nutritionally significant amounts at the per person scale. However, unlike many tropical zones, none of the species harvested can be considered high-priority conservation species. Even densely populated and heavily harvested communal lands appear to offer high wild meat off-takes from low conservation priority species.
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, Sarah A H , Shackleton, Charlie M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6638 , http://hdl.handle.net/10962/d1006864
- Description: When compared to tropical forest zones in west and central Africa, off-take of wild meat from savannah and grassland biomes by local rural communities has not been well assessed. This case study of wild meat collection activities within a rural community in the Mount Frere region of the Eastern Cape (South Africa) uses last-catch records derived from 50 wild meat gatherers to calculate average off-take of taxa, species and fresh mass of wild meat per collection event. When per-event off take is overlaid onto household hunting frequency data, annual off-take would be 268.6 kg km−2 yr−1 or 3 kg person−1 yr−1 presuming constant off-take over an annual period. Monetary value of off-take would be South African R 307 (US$ 39) per household annually. For some species, off-take weight per km2 shows similar values to data from tropical forest zones, but high human population densities tend to dilute off-takes to less nutritionally significant amounts at the per person scale. However, unlike many tropical zones, none of the species harvested can be considered high-priority conservation species. Even densely populated and heavily harvested communal lands appear to offer high wild meat off-takes from low conservation priority species.
- Full Text:
- Date Issued: 2009
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
Re-examining local and market-orientated use of wild species for the conservation of biodiversity
- Authors: Shackleton, Charlie M
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6655 , http://hdl.handle.net/10962/d1007071
- Description: The hypothesis of attaching and realising market values as one means of conserving biodiversity has gained ground over the last decade. This has been challenged recently after examination of a number of case studies, largely from tropical Amazonia, on high value logging, marketing of non-timber forest products, and bioprospecting. The conclusion was that market-orientated conservation has seldom generated the financial returns envisaged, and as such cannot be used as an incentive to prevent land transformation. This paper reviews the basis of the challenge to market-orientated conservation on a number of grounds, drawing on examples largely from southern Africa. It concludes that generalizations from tropical Amazonia regarding the failure of market-orientated conservation are probably premature, and that it should remain an option, amongst a number of options, for conservation of biodiversity. Additionally, the prerequisite criteria identified as necessary to create an enabling framework for the success of market-orientated conservation are insufficient. Case studies are presented where the prerequisites do not apply, yet current extraction for market purposes is sustainable. Other potential prerequisites are also considered. There is a need for multivariate analysis, based on a large sample size drawn from across a range of environments and resources, of which factors are important prerequisites for successful market-orientated conservation, and under which circumstances.
- Full Text:
- Date Issued: 2001
- Authors: Shackleton, Charlie M
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6655 , http://hdl.handle.net/10962/d1007071
- Description: The hypothesis of attaching and realising market values as one means of conserving biodiversity has gained ground over the last decade. This has been challenged recently after examination of a number of case studies, largely from tropical Amazonia, on high value logging, marketing of non-timber forest products, and bioprospecting. The conclusion was that market-orientated conservation has seldom generated the financial returns envisaged, and as such cannot be used as an incentive to prevent land transformation. This paper reviews the basis of the challenge to market-orientated conservation on a number of grounds, drawing on examples largely from southern Africa. It concludes that generalizations from tropical Amazonia regarding the failure of market-orientated conservation are probably premature, and that it should remain an option, amongst a number of options, for conservation of biodiversity. Additionally, the prerequisite criteria identified as necessary to create an enabling framework for the success of market-orientated conservation are insufficient. Case studies are presented where the prerequisites do not apply, yet current extraction for market purposes is sustainable. Other potential prerequisites are also considered. There is a need for multivariate analysis, based on a large sample size drawn from across a range of environments and resources, of which factors are important prerequisites for successful market-orientated conservation, and under which circumstances.
- Full Text:
- Date Issued: 2001
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