http://hdl.handle.net/10204/942 2013-06-19T02:26:54Z http://hdl.handle.net/10204/6792 Title: The current waste generation and management trends in South Africa: A Review Authors: Nkosi, N; Muzenda, E; Zvimba, J; Pilusa, J Abstract: This paper, a continuation and expansion of the work of Muzenda et al, 2012 [1] looks at the current waste generation and management trends in South Africa. The waste tyre problem in South Africa is also briefly discussed. Solid waste management is a growing environmental problem in developing countries such as South Africa. The increasing standard of living and economic growth results in challenges in the management of both general and hazardous waste. Landfill sites life spans have been reduced and hence the need for waste minimization, utilization and alternative disposal methods. Waste tyre management is challenge as they are non compactable and non-biodegradable. The Integrated Waste Management Plan (IWMP) proposed by the Recycling and Economic Initiative of South Africa (REDISA) is a waste tyre recycling and utilization initiative. This paper is review on the current waste generation and management in South Africa. The objectives of this paper were achieved through a literature review. Description: International Conference on Integrated Waste Management and Green Energy Engineering, Johannesburg (South Africa), 15-16 April 2013. Published in Planetary Scientific Research Center 2013-04-01T00:00:00Z http://hdl.handle.net/10204/6782 Title: Comparison of water-use by alien invasive pine trees growing in riparian and non-riparian zones in the Western Cape Province, South Africa Authors: Dzikiti, S; Schachtschneider, K; Naiken, V; Gush, M; Le Maitre, D Abstract: Self-established stands of alien invasive pine trees are common in many parts of South Africa and elsewhere. They mainly invade non-riparian settings but sometimes invade riparian habitats. There are clear visual differences in the physical attributes of trees that occupy riparian and non-riparian zones. We have little information whether the differences between trees growing in these contrasting habitats reflect their water-use. The goal of this study was to establish the water-use of alien invasive pines growing adjacent to and away from a perennial stream, and to determine the driving factors behind the variations. The study was conducted in a self-established 20-year old mixed pine forest occupied by roughly equal proportions of Pinus pinaster and Pinus halepensis. Individual tree transpiration rates were measured using the heat pulse velocity (HPV) sap flow method. Evapotranspiration (ET) from entire stands was determined from the surface energy balance equation using sensible heat flux data collected using a boundary layer scintillometer and measurements of the available energy (net radiation – soil heat flux). A simple two-layer model in which the stand ET was calculated as the algebraic sum of the outputs from transpiration (E) and soil evaporation sub-models was evaluated at the two contrasting sites. Annual transpiration and ET rates were higher in the riparian zone at 980 and 1417 mm compared to 753 and 1190 mm, respectively in the non-riparian area. The model predicted stand transpiration fairly accurately for both sites (average R2 44 > 0.75), but was less accurate for evapotranspiration (average R2 45 < 0.70) due to the difficulties in simulating soil evaporation. No significant differences in sap velocities were found between trees at the two sites so the greater water-use of trees in the riparian zone was due to the larger basal area per stem. Based on the measured transpiration data we conclude that self-sown pine stands growing in riparian zones use at least 36% more water than those occurring in non-riparian settings justifying the high priority given to clearing invasive trees in riparian zones. Description: Copyright: 2013 Elsevier. This is the Pre/post print version of the work. The definitive version is published in Forest Ecology and Management, vol. 293, pp 92-102 2013-04-01T00:00:00Z http://hdl.handle.net/10204/6754 Title: Bacterial community profiling in the rhizosphere of field grown GM and non-GM maize Authors: Bumunang, EW; Babalola, OO; Barros, E Abstract: This study examined the impact of genetically modified corn on bacterial functional community in the rhizosphere. Rhizospheric soil samples from GM and non-GM corn were collected at 30 days after sowing (DAS) and at post-harvest from two experimental fields in Gauteng, South Africa. Plate count results obtained on Pseudomonas selective media indicated 1.5 × 103 cfu in GM and 1.7 × 103 cfu in non-GM soil samples at 30 DAS. At post-harvest, there was 80% decline in the rhizobacteria population in GM sample and 76% in the non-GM. To compare bacterial functional community in GM and non-GM soil, Biolog GN2 microplate, a sole carbon substrate utilization profile, was used and no significant difference was observed. Based on analytical profile index identification system, species of Pseudomonas putida, P. stutzeri and Achromobacter denitrificans were identified in GM and non-GM at 30 DAS. No Pseudomonas species was identified in samples at post-harvest. These findings are of great significance with regards to the investigation of possible impact of GM maize on bacterial functional community in the rhizosphere. Description: Copyright: 2013. Oriental Scientific Publishing. This is an ABSTRACT ONLY. The definitive version is published in Journal of Pure and Applied Microbiology, pp 1-21 2013-01-01T00:00:00Z http://hdl.handle.net/10204/6748 Title: The role of scientists in acid mine drainage policy response in Gauteng, South Africa: Presentation Authors: Funke, N Abstract: The focus of this presentation is to understand the acid mine drainage policy in Gauteng, South Africa, and the role that scientists play within this policy. Description: Berlin Conference on Evidence for Sustainable Development, Berlin, 5-6 October 2012 2012-10-01T00:00:00Z