1. Stockholm Resilience Centre, Stockholm University, Stockholm SE-10691, Sweden;, , , ,
2. Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland 7602, South Africa
3. Beijer Institute, Royal Swedish Academy of Sciences, Stockholm SE-10405, Sweden
4. Department of Geography, University of Victoria, Victoria V8W 2Y2, Canada
5. Centre for Complex Systems in Transition, Stellenbosch University, Matieland 7602, South Africa