Taro （Colocasia esculenta L. Schott） is an important underutilised crop in South Africa, East Africa and Indonesia. Three taro landraces, namely, Dumbe Lomfula （wild）, KwaNgwanase and Umbumbulu, were collected fro...Taro （Colocasia esculenta L. Schott） is an important underutilised crop in South Africa, East Africa and Indonesia. Three taro landraces, namely, Dumbe Lomfula （wild）, KwaNgwanase and Umbumbulu, were collected from two locations in KwaZulu-Natal （KZN）, South Africa, and planted at two locations, Pietermaritzburg （KZN） and Roodeplaat, Pretoria. Ago-morphological characterisation of vegetative and corm characteristics were done four months after planting and at harvest, respectively. Sampling for DNA fingerprinting using five SSR primers was done using leaf material four months after planting. Agro-morphological characterisation was useful in showing differences between the wild landrace and the two cultivated landraces, as well as identification of dasheen and eddoe types. SSR primer characterisation showed that despite significant morphological difference, the wild Dumbe Lomfula and Umbumbulu landraces were closely related but different from the KwaNgwanase landrace. Although landraces showed great morphological variation, this did not necessarily imply genetic variation. It is concluded that SSR primers are more useful for characterising taro landraces.展开更多
Biological diversity involves genetic, species, and ecosystem diversity. Genetic diversity denotes the variation within species in the functional units of heredity present in any plant or animal, microbial or other or...Biological diversity involves genetic, species, and ecosystem diversity. Genetic diversity denotes the variation within species in the functional units of heredity present in any plant or animal, microbial or other origin of living things. Species diversity encompasses the variety of species--whether wild or domesticated, within a geographical area. This study assesses the economic value of crop productivity biodiversity in Ijebu Ode agricultural zone of Ogun State. The authors proposed a dynamic model of market equilibrium with vertical product differentiation that enabled us to take into account the economic consequences of respondents＇ monthly income and species crop of three different communities. The objectives of the study are to identify the personal and socio-economic characteristics of farmers and determine the importance of biodiversity in the study area using Simpson＇s Index. The result showed that 52.50% were male, majority （32.50%） were within the age range of 31 and 40 years old, 44.17% were married, 62.50% had household size of 6-10, and majority （45.83%） had secondary education while 46.67% had up to 20 years farming experience. In conclusion, the authors find that effective factors play an important role in explaining the support for biodiversity conservation, particularly when people do not have specific knowledge about species; while ecological-scientific considerations appear when people are well-informed.展开更多
Decades of commercial planting and other anthropogenic processes are posing a threat to the riparian landscapes of the Cauvery river basin, which supports a high floral diversity. Despite this, the habitats in the ups...Decades of commercial planting and other anthropogenic processes are posing a threat to the riparian landscapes of the Cauvery river basin, which supports a high floral diversity. Despite this, the habitats in the upstream sections of the River Cauvery are still intact, as they are located in sacred groves. To understand the dynamism of riparian forests exposed to anthropogenic pressures, the upstream stretch of Cauvery extending from Kushalanagara to Talacauvery （~102 km） was categorized into two landscapes： agro ecosystem and sacred （i.e. preserved）. The tree species were sampled using belt transects at 5 km intervals and the regeneration status of endemic species assessed using quadrats. A total of 128 species belonging to 47 families, and representing 1,590 individuals, was observed. Amongst them, 65% of unique species were exclusive to sacred landscapes. A rarefaction plot confirmed higher species richness for the sacred compared to the agro ecosystem landscapes, and diversity indices with more evenness in distribution were evident in sacred landscapes. A significant loss of endemic tree species in the agro ecosystem landscapes was found. Overall, this study demonstrates that an intense biotic pressure in terms of plantations and other anthropogenic activities have altered the species composition of the riparian zone in non-sacred areas. A permanent policy implication is required for the conservation of riparian buffers to avoid further ecosystem degradation and loss of biodiversity.展开更多
The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracru...The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracruz. It is practiced in mono-crop plantations by the majority of farmers, who are rendered vulnerable to price depreciation resulting from simultaneous harvest and over-supply of a single commodity. Some farmers have associated multiple crops in citrus farms （agroforestry techniques） as a strategy to improve their livelihoods. Farmers who increased agrobiodiversity in their farms have significantly improved their livelihoods compared to mono-crop plantation owners. The research shows that increased agro-biodiversity can be a strategy to improve the livelihoods of citrus producers in the state of Veracruz, with significant economic benefits depending on the crop combination： maize-citrus is the least economically profitable combination （providing 21% in terms of internal rate of return）, while pineapple-citrus, banana-citrus and vanilla-citrus give higher returns （41%, 44% and 221% respectively）. The citrus-vanilla crop combination also has the highest benefit-cost ratio, relative to citrus monocrop （1.91） as well as the highest net present value （MX$579,635.73）. The choice of crop ultimately depends on the farmer＇s priorities. The associated benefits can be classified in three ways which correspond to the tripartite goal of sustainable development： （i） ecological sustainability （through increased ecosystem resilience）, （ii） economic stability （through diversified, less risk-prone sources of income）, and （iii） social well-being （through lower）.展开更多
文摘Taro （Colocasia esculenta L. Schott） is an important underutilised crop in South Africa, East Africa and Indonesia. Three taro landraces, namely, Dumbe Lomfula （wild）, KwaNgwanase and Umbumbulu, were collected from two locations in KwaZulu-Natal （KZN）, South Africa, and planted at two locations, Pietermaritzburg （KZN） and Roodeplaat, Pretoria. Ago-morphological characterisation of vegetative and corm characteristics were done four months after planting and at harvest, respectively. Sampling for DNA fingerprinting using five SSR primers was done using leaf material four months after planting. Agro-morphological characterisation was useful in showing differences between the wild landrace and the two cultivated landraces, as well as identification of dasheen and eddoe types. SSR primer characterisation showed that despite significant morphological difference, the wild Dumbe Lomfula and Umbumbulu landraces were closely related but different from the KwaNgwanase landrace. Although landraces showed great morphological variation, this did not necessarily imply genetic variation. It is concluded that SSR primers are more useful for characterising taro landraces.
文摘Biological diversity involves genetic, species, and ecosystem diversity. Genetic diversity denotes the variation within species in the functional units of heredity present in any plant or animal, microbial or other origin of living things. Species diversity encompasses the variety of species--whether wild or domesticated, within a geographical area. This study assesses the economic value of crop productivity biodiversity in Ijebu Ode agricultural zone of Ogun State. The authors proposed a dynamic model of market equilibrium with vertical product differentiation that enabled us to take into account the economic consequences of respondents＇ monthly income and species crop of three different communities. The objectives of the study are to identify the personal and socio-economic characteristics of farmers and determine the importance of biodiversity in the study area using Simpson＇s Index. The result showed that 52.50% were male, majority （32.50%） were within the age range of 31 and 40 years old, 44.17% were married, 62.50% had household size of 6-10, and majority （45.83%） had secondary education while 46.67% had up to 20 years farming experience. In conclusion, the authors find that effective factors play an important role in explaining the support for biodiversity conservation, particularly when people do not have specific knowledge about species; while ecological-scientific considerations appear when people are well-informed.
文摘Decades of commercial planting and other anthropogenic processes are posing a threat to the riparian landscapes of the Cauvery river basin, which supports a high floral diversity. Despite this, the habitats in the upstream sections of the River Cauvery are still intact, as they are located in sacred groves. To understand the dynamism of riparian forests exposed to anthropogenic pressures, the upstream stretch of Cauvery extending from Kushalanagara to Talacauvery （~102 km） was categorized into two landscapes： agro ecosystem and sacred （i.e. preserved）. The tree species were sampled using belt transects at 5 km intervals and the regeneration status of endemic species assessed using quadrats. A total of 128 species belonging to 47 families, and representing 1,590 individuals, was observed. Amongst them, 65% of unique species were exclusive to sacred landscapes. A rarefaction plot confirmed higher species richness for the sacred compared to the agro ecosystem landscapes, and diversity indices with more evenness in distribution were evident in sacred landscapes. A significant loss of endemic tree species in the agro ecosystem landscapes was found. Overall, this study demonstrates that an intense biotic pressure in terms of plantations and other anthropogenic activities have altered the species composition of the riparian zone in non-sacred areas. A permanent policy implication is required for the conservation of riparian buffers to avoid further ecosystem degradation and loss of biodiversity.
文摘The present article examines the livelihood benefits associated with agrobiodiversity in Veracruz, Mexico. Citrus-based agriculture is the principal economic activity in the agricultural sector of the state of Veracruz. It is practiced in mono-crop plantations by the majority of farmers, who are rendered vulnerable to price depreciation resulting from simultaneous harvest and over-supply of a single commodity. Some farmers have associated multiple crops in citrus farms （agroforestry techniques） as a strategy to improve their livelihoods. Farmers who increased agrobiodiversity in their farms have significantly improved their livelihoods compared to mono-crop plantation owners. The research shows that increased agro-biodiversity can be a strategy to improve the livelihoods of citrus producers in the state of Veracruz, with significant economic benefits depending on the crop combination： maize-citrus is the least economically profitable combination （providing 21% in terms of internal rate of return）, while pineapple-citrus, banana-citrus and vanilla-citrus give higher returns （41%, 44% and 221% respectively）. The citrus-vanilla crop combination also has the highest benefit-cost ratio, relative to citrus monocrop （1.91） as well as the highest net present value （MX$579,635.73）. The choice of crop ultimately depends on the farmer＇s priorities. The associated benefits can be classified in three ways which correspond to the tripartite goal of sustainable development： （i） ecological sustainability （through increased ecosystem resilience）, （ii） economic stability （through diversified, less risk-prone sources of income）, and （iii） social well-being （through lower）.
