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Arthropod and plant diversity of maize agro-ecosystems in the grassland and savanna biomes of South Africa / Monique BothaBotha, Monique January 2014 (has links)
Maize (Zea mays L.) is the most important grain crop in the country. Approximately 12 million tons of maize grain is produced annually on approximately 2.5 million ha of land. However, increased farming intensity can lead to fragmentation of habitat and has a tendency to decrease the biodiversity of an area. Therefore, to ensure the continued functionality of agro-ecosystems, methods in agriculture must be assessed and adapted when necessary to ensure the persistence of biological diversity. Unfortunately, the effect of crop production on species diversity and composition in South Africa is still relatively unknown, and no baseline data exists with which to gauge the possibility of unknown extinction risks of important biological elements. The objectives of this study were to compare plant and arthropod diversity patterns and species turnover of maize agro-ecosystems between biomes (grassland and savanna) and along a maize field-field margin gradient (MAFFMAG). Surveys of maize agro-ecosystems were conducted in six provinces of South Africa, namely North-West, Mpumalanga, KwaZulu-Natal, Limpopo, Free State and the Eastern Cape. Repeated measures ANOVA revealed a significantly lower plant and arthropod species diversity and richness in maize fields compared to field margins. Non-metric multidimensional scaling revealed that arthropod species composition differed between biomes although not along MAFFMAGs, indicating that arthropod species composition is dependent on biome rather than distance from maize field. Floristic data revealed unique species compositions for maize fields and field margins and also for biomes. Furthermore, maize fields and field margins of grassland sites were more similar in plant species composition than the savanna localities, suggesting higher regional beta diversity for savanna regions. Spearman‘s rank order correlations revealed generally positive but weak or no relationships between plant and arthropod diversity. This study provides baseline data for identification, monitoring and conservation of priority species and will allow the future evaluation of ecosystem services provided by plants and associated arthropods, especially natural enemies of pests, in maize agro-ecosystems. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
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Arthropod and plant diversity of maize agro-ecosystems in the grassland and savanna biomes of South Africa / Monique BothaBotha, Monique January 2014 (has links)
Maize (Zea mays L.) is the most important grain crop in the country. Approximately 12 million tons of maize grain is produced annually on approximately 2.5 million ha of land. However, increased farming intensity can lead to fragmentation of habitat and has a tendency to decrease the biodiversity of an area. Therefore, to ensure the continued functionality of agro-ecosystems, methods in agriculture must be assessed and adapted when necessary to ensure the persistence of biological diversity. Unfortunately, the effect of crop production on species diversity and composition in South Africa is still relatively unknown, and no baseline data exists with which to gauge the possibility of unknown extinction risks of important biological elements. The objectives of this study were to compare plant and arthropod diversity patterns and species turnover of maize agro-ecosystems between biomes (grassland and savanna) and along a maize field-field margin gradient (MAFFMAG). Surveys of maize agro-ecosystems were conducted in six provinces of South Africa, namely North-West, Mpumalanga, KwaZulu-Natal, Limpopo, Free State and the Eastern Cape. Repeated measures ANOVA revealed a significantly lower plant and arthropod species diversity and richness in maize fields compared to field margins. Non-metric multidimensional scaling revealed that arthropod species composition differed between biomes although not along MAFFMAGs, indicating that arthropod species composition is dependent on biome rather than distance from maize field. Floristic data revealed unique species compositions for maize fields and field margins and also for biomes. Furthermore, maize fields and field margins of grassland sites were more similar in plant species composition than the savanna localities, suggesting higher regional beta diversity for savanna regions. Spearman‘s rank order correlations revealed generally positive but weak or no relationships between plant and arthropod diversity. This study provides baseline data for identification, monitoring and conservation of priority species and will allow the future evaluation of ecosystem services provided by plants and associated arthropods, especially natural enemies of pests, in maize agro-ecosystems. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
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Plant and arthropod diversity of maize agro–ecosystems in the Highveld and Lowveld regions of South Africa / Bheki George MalibaMaliba, Bheki George January 2011 (has links)
Surveys of plant and selected insect species was conducted in Highveld and Lowveld
agro–ecosystems of four provinces of South Africa, namely North–West, Mpumalanga,
KwaZulu–Natal and Limpopo. The objectives of the study were to compare insect and
plant diversity between localities (grassland and savanna) and treatments (maize field,
semi–transformed and untransformed) to test for a general relationship between plant
and insect diversity along a maize field–field margin gradient. Plant and insect diversity
patterns were studied along the gradient and quantified in terms of richness and
diversity indices. Plant and insect species compositional turnover was also measured
along the maize field–field margin gradient. Plant diversity increased with increasing
distance from maize fields into the margin. The flora in maize fields and of margins
differed, but in contrast, insect species assemblages were similar in maize fields and
margins. There was no statistical difference in insect diversity between treatments
(maize field, semi–transformed and transformed). A relationship was revealed between
plant and insect diversity, as plant diversity enhanced insect diversity. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2011.
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Plant and arthropod diversity of maize agro–ecosystems in the Highveld and Lowveld regions of South Africa / Bheki George MalibaMaliba, Bheki George January 2011 (has links)
Surveys of plant and selected insect species was conducted in Highveld and Lowveld
agro–ecosystems of four provinces of South Africa, namely North–West, Mpumalanga,
KwaZulu–Natal and Limpopo. The objectives of the study were to compare insect and
plant diversity between localities (grassland and savanna) and treatments (maize field,
semi–transformed and untransformed) to test for a general relationship between plant
and insect diversity along a maize field–field margin gradient. Plant and insect diversity
patterns were studied along the gradient and quantified in terms of richness and
diversity indices. Plant and insect species compositional turnover was also measured
along the maize field–field margin gradient. Plant diversity increased with increasing
distance from maize fields into the margin. The flora in maize fields and of margins
differed, but in contrast, insect species assemblages were similar in maize fields and
margins. There was no statistical difference in insect diversity between treatments
(maize field, semi–transformed and transformed). A relationship was revealed between
plant and insect diversity, as plant diversity enhanced insect diversity. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2011.
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