Mapping impacts of alien species on biodiversity in the face of climate change

Abstract Risk maps are a useful tool to prioritise sites for management and allocate resources where they are most needed as they can show us where impacts of biological invasions are most likely to happen or expected to be largest. Given the pace of global changes, we need to understand not only the risks under current conditions, but future risks taking into account aspects such as climate change. In this study, we use Australian acacias alien to South Africa as a case study to model their potential distribution under climate change scenarios, and map their potential impacts and the uncertainty related to variability across socio-economic pathways and climatic models, to help us set better priorities for the future. We found that although climatic suitability and therefore the potential high risk area is predicted to decrease under climate change, the highly vulnerable fynbos biome remains an area with high projected impacts. We found that potential impacts would decrease under climate change within protected areas of the Western Cape. However, in this province, national parks and other areas with high levels of protection would experience greater impacts than private protected areas of lower protection status. This can help us prioritise management actions and aid the development of suitable plans to protect biodiversity not only under current, but also future climate conditions.