1. Potsdam Institute for Climate Impact Research (PIK); Telegraphenberg A31 Potsdam 14473 Germany
2. Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); Berlin 14195 Germany
3. Max-Planck-Institute for Biogeochemistry; Jena 07745 Germany
4. Forest Ecology and Forest Management Group; Wageningen University; PO Box 47 Wageningen 6700AA The Netherlands
5. Global Ecology Unit CREAF-CSIC-UAB; CSIC; Cerdanyola del Vallés 08193 Catalonia Spain
6. CREAF; Cerdanyola del Vallès 08193 Catalonia Spain