1. Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
2. School of International Development, University of East Anglia, Norwich NR4 7TJ, Norfolk, England
3. Institute of Environmental Science and Technology, and Department of Economics and Economic History, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
4. Mpingo Conservation and Development Initiative, Kilwa Masoko, Tanzania