1. Finnish Environment Institute (SYKE); P.O. Box 140 Helsinki FI-00251 Finland
2. European Commission Joint Research Centre; Directorate D Sustainable Resources; Via E. Fermi 2749, TP 440 Ispra (VA) 210207 Italy
3. Kainuu Centre for Economic Development; Transport and the Environment; P.O. Box 115 Kajaani FI-87101 Finland