1. Division of Conservation Biology, Vegetation and Landscape Ecology University of Vienna Vienna Austria
2. Department of Mathematical Sciences, Centre for Invasions Biology Stellenbosch University Matieland South Africa
3. Department de Ciències Ambientals, Facultat de Ciències Universitat de Girona Girona Catalonia Spain
4. Mathematical and Physical Biosciences African Institute for Mathematical Sciences Muizenberg South Africa