1. Institute of Biological and Environmental Sciences; School of Biological Sciences; University of Aberdeen; Aberdeen AB24 3UU UK
2. Greenpeace Research Laboratories; School of Biosciences; University of Exeter; Exeter EX4 4RN UK
3. European Commission - DG Joint Research Centre, Institute for Environment and Sustainability; Via E. Fermi 2749 Ispra (VA) 21027 Italy
4. Alterra, Wageningen University and Research Centre; P.O. Box 47 Wageningen 6700 AA The Netherlands