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Chemically unusual essential oils from arid zones
368
Abstracts
A thorough literature survey of books, journal articles, checklists, grey literature and published ethnobotanical surveys showed that there are more than 1500 edible plants (including indigenous and naturalized exotics) in southern Africa. A comprehensive checklist of all edible plants has been compiled, together with a study of the main patterns of food plant use in the region. The list includes 500 new records of plants not previously included in standard reference works such as "Food from the Veld" by Fox and Norwood Young (1982). An analysis of the relative importance of plant families revealed that the Apocynaceae contributes the highest number of edible taxa. This is surprising, as wellknown food plant families such as the Fabaceae, Asteraceae and Poaceae were expected to occupy the number one spot. The seemingly unique pattern is also reflected in sub-Saharan Africa, with Apocynaceae being the second most important family, after Fabaceae. Within southern African, the Apocynaceae was found to be important in different cultures and regions. Fruits represent the largest food category in southern Africa, followed by vegetables, underground storage organs, beverages and seeds and nuts. Other important categories have been identified such as yeast plants (used as ferment in making bread and beer) and sources of moisture.
Population ecology of Pterocarpus angolensis DC. at the Lowveld National Botanical Gardens, Mpumalanga Province T. Sadiki, M.P. Tshisikhawe Department of Botany, School of Mathematical and Natural Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa E-mail address: [email protected] (T. Sadiki) Pterocarpus angolensis DC is a tree species belonging to the Fabaceae (pea) family and is utilized for various purposes around the world. In South Africa, it is mainly used for its medicinal bark and its good quality wood is used for furniture. The great demand of the species has resulted in high level of harvesting wherever it grows. Its overexploitation is threatening the viability of its populations. This study aimed at understanding the current status of a population found in the pristine area of the Lowveld National Botanical Gardens. Data on population parameters were collected in 14 transects of 100 m x 5 m in sizes. Parameters sampled were plant height, crown health estimates, stem circumferences and evidence of debarking. Results showed a healthy population that displayed an inverse J-shaped curve as analysed from some of the parameters sampled. The population in the Lowveld National Botanical Gardens should be monitored in order to keep its good health status.
doi:10.1016/j.sajb.2017.01.172
doi:10.1016/j.sajb.2017.01.174
Chemically unusual essential oils from arid zones
Feeding patterns of elephants at the Atherstone Collaborative Nature Reserve
N.J. Sadgrove, I.M. Hulley, O. Sobiyi, B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa E-mail address: [email protected] (N.J. Sadgrove)
Evolutionary pressures in arid zones have favoured the selection of phenotypes with high yields of secondary metabolites that are theorised to confer advantages that are not fully realised in the ecological context. Nevertheless such metabolites are well represented by small lipophilic volatiles that may be hydrodistilled to yield novel and interesting essential oils with noteworthy biological activity. Our research group has dedicated much time to the chemical elucidation of essential oils from arid zones of both Southern Africa and Australia and many striking and unusual features have emerged. In the course of our investigation new structures have been elucidated, particularly from Southern African species. These include a methylsulfanyl ester from Annesorhiza nuda (Apiaceae) and a diterpene ketone from Croton gratissimus (Euphorbiaceae). The latter is atypical in an essential oil due to the low volatility of diterpenes. Other essential oil studies in the African context include the aromatic tea plant Leyserra gnaphalioides (Asteraceae), the chemovariable oils from Penzia incana, the chamazulene rich (blue coloured) oil from P. punctata (Asteraceae) and the lemon scented oil from Pelargonium crispum (Geraniaceae). In the Australian context many furanosesquiterpenes have been observed from Eremophila (Scrophulariaceae) but the most unusual yet pleasant oil was composed predominantly of a novel iridoid which we named myodesert-1-ene. Thus, our studies have elucidated the striking diversity of essential oils that concentrate in the arid zones.
doi:10.1016/j.sajb.2017.01.173
M.Q. Seloanaa, J.J. Jordaana, M.J. Potgietera, J.W. Krugerb a University of Limpopo, Department of Biodiversity, PO Box 1106, Sovenga 0727, South Africa b Department of Economic Development, Environment and Tourism, Private Bag X9484, Polokwane 0700, South Africa E-mail address: [email protected] (M.Q. Seloana) The African savanna elephant (Loxodonta africana Blumenbach) is a generalist herbivore relying on widely distributed resources. Their diet consists predominantly of green grass and forbs in the wet season, as well as green browse in the late wet and beginning of the dry season. This study aimed to investigate feeding patterns of elephants in the enclosed bushveld savanna at the Atherstone Collaborative Nature Reserve. The objectives of the study were to assess selection of different components of vegetation; identify plants that play a major role in their diet; and document plant parts mostly consumed by elephants. Dry (May to October) and wet (November to April) seasonal distribution and movement patterns of elephants were studied over a period of a year based on direct observation of identified elephant groups and indirect observation of elephant signs, foot prints, dung piles and feeding signs. Data was collected on the basis of the herbaceous and woody components’ consumption; counting all individuals occurring in each feeding plot on a species basis to represent tree density. Species preference was determined by both selection frequency and species abundance and identifying the plant parts browsed. A total of 49 species (trees, shrubs, grasses and forbs) were recorded within all the feeding plots. A continued decline in vegetation, aggravated by elephants, could compromise local conservation efforts. It is therefore imperative to understand factors that drive elephants to exhibiting a hierarchical selection for certain vegetation. doi:10.1016/j.sajb.2017.01.175
Abstracts
A thorough literature survey of books, journal articles, checklists, grey literature and published ethnobotanical surveys showed that there are more than 1500 edible plants (including indigenous and naturalized exotics) in southern Africa. A comprehensive checklist of all edible plants has been compiled, together with a study of the main patterns of food plant use in the region. The list includes 500 new records of plants not previously included in standard reference works such as "Food from the Veld" by Fox and Norwood Young (1982). An analysis of the relative importance of plant families revealed that the Apocynaceae contributes the highest number of edible taxa. This is surprising, as wellknown food plant families such as the Fabaceae, Asteraceae and Poaceae were expected to occupy the number one spot. The seemingly unique pattern is also reflected in sub-Saharan Africa, with Apocynaceae being the second most important family, after Fabaceae. Within southern African, the Apocynaceae was found to be important in different cultures and regions. Fruits represent the largest food category in southern Africa, followed by vegetables, underground storage organs, beverages and seeds and nuts. Other important categories have been identified such as yeast plants (used as ferment in making bread and beer) and sources of moisture.
Population ecology of Pterocarpus angolensis DC. at the Lowveld National Botanical Gardens, Mpumalanga Province T. Sadiki, M.P. Tshisikhawe Department of Botany, School of Mathematical and Natural Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa E-mail address: [email protected] (T. Sadiki) Pterocarpus angolensis DC is a tree species belonging to the Fabaceae (pea) family and is utilized for various purposes around the world. In South Africa, it is mainly used for its medicinal bark and its good quality wood is used for furniture. The great demand of the species has resulted in high level of harvesting wherever it grows. Its overexploitation is threatening the viability of its populations. This study aimed at understanding the current status of a population found in the pristine area of the Lowveld National Botanical Gardens. Data on population parameters were collected in 14 transects of 100 m x 5 m in sizes. Parameters sampled were plant height, crown health estimates, stem circumferences and evidence of debarking. Results showed a healthy population that displayed an inverse J-shaped curve as analysed from some of the parameters sampled. The population in the Lowveld National Botanical Gardens should be monitored in order to keep its good health status.
doi:10.1016/j.sajb.2017.01.172
doi:10.1016/j.sajb.2017.01.174
Chemically unusual essential oils from arid zones
Feeding patterns of elephants at the Atherstone Collaborative Nature Reserve
N.J. Sadgrove, I.M. Hulley, O. Sobiyi, B.-E. Van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa E-mail address: [email protected] (N.J. Sadgrove)
Evolutionary pressures in arid zones have favoured the selection of phenotypes with high yields of secondary metabolites that are theorised to confer advantages that are not fully realised in the ecological context. Nevertheless such metabolites are well represented by small lipophilic volatiles that may be hydrodistilled to yield novel and interesting essential oils with noteworthy biological activity. Our research group has dedicated much time to the chemical elucidation of essential oils from arid zones of both Southern Africa and Australia and many striking and unusual features have emerged. In the course of our investigation new structures have been elucidated, particularly from Southern African species. These include a methylsulfanyl ester from Annesorhiza nuda (Apiaceae) and a diterpene ketone from Croton gratissimus (Euphorbiaceae). The latter is atypical in an essential oil due to the low volatility of diterpenes. Other essential oil studies in the African context include the aromatic tea plant Leyserra gnaphalioides (Asteraceae), the chemovariable oils from Penzia incana, the chamazulene rich (blue coloured) oil from P. punctata (Asteraceae) and the lemon scented oil from Pelargonium crispum (Geraniaceae). In the Australian context many furanosesquiterpenes have been observed from Eremophila (Scrophulariaceae) but the most unusual yet pleasant oil was composed predominantly of a novel iridoid which we named myodesert-1-ene. Thus, our studies have elucidated the striking diversity of essential oils that concentrate in the arid zones.
doi:10.1016/j.sajb.2017.01.173
M.Q. Seloanaa, J.J. Jordaana, M.J. Potgietera, J.W. Krugerb a University of Limpopo, Department of Biodiversity, PO Box 1106, Sovenga 0727, South Africa b Department of Economic Development, Environment and Tourism, Private Bag X9484, Polokwane 0700, South Africa E-mail address: [email protected] (M.Q. Seloana) The African savanna elephant (Loxodonta africana Blumenbach) is a generalist herbivore relying on widely distributed resources. Their diet consists predominantly of green grass and forbs in the wet season, as well as green browse in the late wet and beginning of the dry season. This study aimed to investigate feeding patterns of elephants in the enclosed bushveld savanna at the Atherstone Collaborative Nature Reserve. The objectives of the study were to assess selection of different components of vegetation; identify plants that play a major role in their diet; and document plant parts mostly consumed by elephants. Dry (May to October) and wet (November to April) seasonal distribution and movement patterns of elephants were studied over a period of a year based on direct observation of identified elephant groups and indirect observation of elephant signs, foot prints, dung piles and feeding signs. Data was collected on the basis of the herbaceous and woody components’ consumption; counting all individuals occurring in each feeding plot on a species basis to represent tree density. Species preference was determined by both selection frequency and species abundance and identifying the plant parts browsed. A total of 49 species (trees, shrubs, grasses and forbs) were recorded within all the feeding plots. A continued decline in vegetation, aggravated by elephants, could compromise local conservation efforts. It is therefore imperative to understand factors that drive elephants to exhibiting a hierarchical selection for certain vegetation. doi:10.1016/j.sajb.2017.01.175