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.

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.

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

Urbanisation is an ever-growing global phenomenon which creates altered environments characterised by increased human habitation, exotic species, impermeable surfaces, artificial structures, landscape fragmentation, habitat loss, and modified energy– and resource pathways. The vulnerable Rand Highveld Grassland vegetation unit in the Tlokwe Municipal area, South Africa, has been extensively degraded and transformed by urbanisation and agriculture. Only 1% of this endangered ecosystem is currently being actively conserved. Grassland fragments in urban areas are considered to be less species rich and less functional than their more “natural” counterparts, and are therefore not a priority for conservation. In this study the effects of landscape matrix quality on intra patch variables, namely plant species diversity and functional diversity, and fine-scale biogeochemical landscape function (as determined by Landscape Function Analysis or LFA) of 30 fragments of the Rand Highveld Grassland vegetation unit were explored. Four urbanisation measures (percentage urban land cover, percentage grass land cover, edge density, and density of people), acting as indicators for patterns and processes associated with urban areas, were calculated for matrix areas with a 500m radius surrounding each selected grassland fragment to quantify the position of each grassland remnant along an urban-to-rural gradient. Using the specific urbanisation measures, the grassland fragments were objectively classified into two classes of urbanisation, namely “rural/peri-urban” and “urban”, to allow for statistical comparisons between intra-patch variables for grassland remnants exposed to similar urbanisation pressures. Plant species composition and diversity were determined in the selected grassland fragments and nine functional traits were described for each species. Plant functional diversity was determined by five functional diversity indices, namely functional richness, evenness, divergence, dispersion, and specialisation. Fine-scale biogeochemical landscape function was determined by executing the LFA method. LFA assesses fine-scale landscape patchiness and 11 soil surface indicators to produce three main LFA parameters (stability, infiltration, and nutrient cycling), which indicates how well a system is functioning in terms of resource conservation and soil processes. Possible relationships between fine-scale biogeochemical landscape function and plant species- and functional diversity were also investigated. NMDS ordinations and basic statistics were used to determine trends and effects within the data. The results indicated that urban grassland remnants had lower mean plant species richness, Shannon species diversity (significantly), and Pielou species evenness than rural/peri-urban grassland fragments. Urban grassland fragments also contained significantly higher percentage of exotic species. Correlations were found between the four urbanisation measures and percentage species of the total species richness possessing certain functional attributes. This indicated that increased urbanisation may influence the species composition and the occurrence of certain plant traits in the selected grassland fragments. Urbanisation seems to have no effect on fine-scale landscape heterogeneity of the selected grassland fragments. Rural/peri-urban grassland fragments had higher infiltration capacity, nutrient cycling potential, and total SSA functionality (although not significantly), which may be ascribed to differences in management practices, such as mowing in urban areas and grazing in rural areas. Rand Highveld Grassland fragments in the urban landscape matrix of Potchefstroom city are just as conservable in terms of plant species diversity and functional diversity, as well as on a biophysical function level involving soil processes than rural/peri-urban grassland fragments. High plant species diversity and the presence of certain plant traits did not contribute to high soil surface stability, infiltration capacity, nutrient cycling potential and total soil surface functioning. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2013

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

Urbanisation is an ever-growing global phenomenon which creates altered environments characterised by increased human habitation, exotic species, impermeable surfaces, artificial structures, landscape fragmentation, habitat loss, and modified energy– and resource pathways. The vulnerable Rand Highveld Grassland vegetation unit in the Tlokwe Municipal area, South Africa, has been extensively degraded and transformed by urbanisation and agriculture. Only 1% of this endangered ecosystem is currently being actively conserved. Grassland fragments in urban areas are considered to be less species rich and less functional than their more “natural” counterparts, and are therefore not a priority for conservation. In this study the effects of landscape matrix quality on intra patch variables, namely plant species diversity and functional diversity, and fine-scale biogeochemical landscape function (as determined by Landscape Function Analysis or LFA) of 30 fragments of the Rand Highveld Grassland vegetation unit were explored. Four urbanisation measures (percentage urban land cover, percentage grass land cover, edge density, and density of people), acting as indicators for patterns and processes associated with urban areas, were calculated for matrix areas with a 500m radius surrounding each selected grassland fragment to quantify the position of each grassland remnant along an urban-to-rural gradient. Using the specific urbanisation measures, the grassland fragments were objectively classified into two classes of urbanisation, namely “rural/peri-urban” and “urban”, to allow for statistical comparisons between intra-patch variables for grassland remnants exposed to similar urbanisation pressures. Plant species composition and diversity were determined in the selected grassland fragments and nine functional traits were described for each species. Plant functional diversity was determined by five functional diversity indices, namely functional richness, evenness, divergence, dispersion, and specialisation. Fine-scale biogeochemical landscape function was determined by executing the LFA method. LFA assesses fine-scale landscape patchiness and 11 soil surface indicators to produce three main LFA parameters (stability, infiltration, and nutrient cycling), which indicates how well a system is functioning in terms of resource conservation and soil processes. Possible relationships between fine-scale biogeochemical landscape function and plant species- and functional diversity were also investigated. NMDS ordinations and basic statistics were used to determine trends and effects within the data. The results indicated that urban grassland remnants had lower mean plant species richness, Shannon species diversity (significantly), and Pielou species evenness than rural/peri-urban grassland fragments. Urban grassland fragments also contained significantly higher percentage of exotic species. Correlations were found between the four urbanisation measures and percentage species of the total species richness possessing certain functional attributes. This indicated that increased urbanisation may influence the species composition and the occurrence of certain plant traits in the selected grassland fragments. Urbanisation seems to have no effect on fine-scale landscape heterogeneity of the selected grassland fragments. Rural/peri-urban grassland fragments had higher infiltration capacity, nutrient cycling potential, and total SSA functionality (although not significantly), which may be ascribed to differences in management practices, such as mowing in urban areas and grazing in rural areas. Rand Highveld Grassland fragments in the urban landscape matrix of Potchefstroom city are just as conservable in terms of plant species diversity and functional diversity, as well as on a biophysical function level involving soil processes than rural/peri-urban grassland fragments. High plant species diversity and the presence of certain plant traits did not contribute to high soil surface stability, infiltration capacity, nutrient cycling potential and total soil surface functioning. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2013