Prioritisation of targets for weed biological control III: a tool to identify the next targets for biological control in South Africa and set priorities for resource allocation

Biological control is an effective and sustainable method for management of invasive alien plants (IAPs), and has been implemented on 68 of the 367 plant species that are listed as legally requiring management strategies under South Africa's National Environmental Management: Biodiversity Act (10/2004): Alien and Invasive Species Regulations. With limited resources and funding available, it can realistically only be considered for a subset of the remaining alien plants for which biocontrol has not yet been implemented. Considerable funding has been allocated towards biocontrol in South African in the past, principally through the Working for Water Programme of the Nature Resource Management Programmes (Department of Environment, Forestry and Fisheries), and this support is expected to continue with the intention of increasing the number of IAPs under this management approach in the future. To ensure appropriate targets are selected, the Biological Control Target Selection (BCTS) system was applied to the alien plants on this list that are not under biocontrol (299 species). This paper presents the resultant list of top priority species that represent good investments for biocontrol when funds are available.