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Abstract: Conservation biological control focuses on enhancing arthropod predator habitats by increasing the natural resources required for survival and reproduction. However, this requires knowledge about the specific requirements of these predators, which can only be acquired from species‐level data. We provide a description of species‐level diversity patterns of the arthropod predator groups Araneae, Coccinellidae, Mantodea and Neuroptera from maize agro‐ecosystems in South Africa. Predators were sampled by sweep‐net at regional and local scales within the Dry Highveld Grassland Bioregion. A list is provided of predators that occurred naturally inside maize agro‐ecosystems, which may be good candidates for the biological control of pests. Diversity indices displayed significantly lower values in maize fields compared with uncultivated vegetation. Marginal and rangeland vegetation had similar diversity levels. Predator diversity of maize was probably dependent on source populations from uncultivated vegetation, highlighting the importance of field margins with respect to maintaining predator diversity in pest management regimes for maize fields. Some predators frequented maize fields, suggesting adaptability to agricultural disturbance. Generalists including Cheilomenes lunata, Chrysoperla congrua and Enoplognatha molesta may be suitable for conservation biocontrol because they can persist in annual agro‐ecosystems year‐round provided that they have access to field margins. [ABSTRACT FROM AUTHOR]

Tropical savannas and grasslands are estimated to contribute significantly to the total primary production of all terrestrial vegetation. Large parts of African savannas and grasslands are used for agriculture and cattle grazing, but the carbon flux data available from these areas are limited. This study explores carbon dioxide fluxes measured with the eddy covariance method for 3 years at a grazed savanna grassland in Welgegund, South Africa. The tree cover around the measurement site, grazed by cattle and sheep, was around 15 %. The night-time respiration was not significantly dependent on either soil moisture or soil temperature on a weekly temporal scale, whereas on an annual timescale higher respiration rates were observed when soil temperatures were higher. The carbon dioxide balances of the years 2010-2011, 2011-2012 and 2012-2013 were -85±16, 67±20 and 139±13 gCm-2 yr-1, respectively. The yearly variation was largely determined by the changes in the early wet season fluxes (September to November) and in the mid-growing season fluxes (December to January). Early rainfall enhanced the respiratory capacity of the ecosystem throughout the year, whereas during the mid-growing season high rainfall resulted in high carbon uptake. [ABSTRACT FROM AUTHOR]