1. Trees and Timber Research Institute IVALSA/CNR, Via Biasi 75, 38010 San Michele All’Adige (TN), Italy
2. Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Campus Ås, Pb 5003, Ås 1430, Akershus, Norway
3. Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Campus Ås, Universitetstunet 3, Ås 1430, Akershus, Norway
4. Norwegian Institute of Bioeconomy Research, Box 115, Ås NO-1431, Norway