1. Faculty of Science and Technology, Free University of Bozen – Bolzano, Piazza Università n. 5, 39100 Bolzano, Italy
2. School of Forest Resources and Conservation, University of Florida-IFAS, PO Box 110410, Newins-Ziegler Hall, Gainesville, FL 32611, USA
3. College of Natural Resources, University of Wisconsin-Stevens Points, Stevens Point, WI 54481, USA
4. Centro de Transporte Sustentable de Mexico, Mexico City, Mexico