Evaluating the efficiency of management approaches for pompom weed control in the Free State

[摘要] The focus of this study was to investigate the efficiency of Alien Invasive Species (AIS) management approaches, as employed by the South African National Biodiversity Institute (SANBI) through their Invasive Species Programme (ISP). Pompom weed was used as an indicator species and the Free State province as a study area. The indicator species was chosen because it is one of the most notorious invasive plants in South Africa, and the study area was consistently managed since ISP inception in 2009.A literature study was conducted to document the importance of invasive species as threats to biodiversity and its components. Properties of the indicator species as well as possible management approaches were listed. The importance of having a functional environmental management system was advocated. Activity Based Costing (ABC) was introduced and its effectiveness in accurate monetary reporting stated. And finally, the importance of Environmental Management Accounting (EMA) and appropriate units for reporting on biodiversity were discussed.An empirical study was conducted wherein species occurrence and abundance were recorded and species trends calculated. Efficiency of management approaches were investigated by performing spectral signature separability analysis, followed by pixel based classification on Landsat 7 and SPOT 5 satellite images. Monetary expenditure was recorded by employing ABC, as per identified activity centres and influenced by cost drivers. Results obtained from this study indicated that pompom weed management approaches were successful in the Free State. These results however, should be interpreted with caution since the localised and fragmented nature of the invasion in Free State made it comparatively easy to manage the species. The result however, gives a good basis upon which modification may be made to accommodate different invasion patterns. Recommendations were made regarding the improvement of field work, the improvement of the accuracy of monetary reporting as well as on the establishment of a functional Environmental Management Accounting (EMA) system

[发布机构] North-West University