[1] Riso DTU, RISO Natl Lab Sustainable Energy, DK-4000 Roskilde, Denmark
[2] Environm Ctr Wales, Ctr Ecol & Hydrol Bangor, Bangor LL572UP, Gwynedd, Wales
[3] Univ Autonoma Barcelona, CREAF Ctr Ecol Res & Foretry Applicat, CSIC CEAB, Ecophysiol & Global Change Unit, E-08193 Barcelona, Spain
[4] Royal Vet & Agr Univ, DK-2970 Horsholm, Denmark
[5] Univ Amsterdam, Inst Biodivers & Ecosyst Dynam Phys Geog, Ctr Geoecol Res ICG, NL-1018 WV Amsterdam, Netherlands
[6] Plant Res Int, NL-6700 AA Wageningen, Netherlands