1. University of Eastern Finland, 163043, Joensuu, Finland;
2. University of Eastern Finland, School of Forest Sciences, Joensuu, Finland, ;
3. University of Eastern Finland, Department of Applied Physics, Kuopio, Finland, ;
4. University of Eastern Finland, Department of Applied Physics, P.O.Box 1627, Kuopio, Finland, 70211;
5. University of Helsinki, 3835, Department of Forest Sciences, Helsinki, Finland;
6. University of Eastern Finland, School of Forest Sciences, Joensuu, Finland, ;
7. University of Eastern Finland, Joensuu, Finland
8. Natural Resources Institute Finland Joensuu, 536630, Joensuu, Finland;