1 Department ofWood Biology and Wood Products, Faculty of Forest, Sciences and Forest Ecologylm, University of Goettingen, Buesgenweg, 4, D-37077, Goettingen, Germany. christian.brischke@uni-goettingen.de.
2 Division of Forest and Forest Resources, Wood Technology, Norwegian Institute of Bioeconomy Research (NIBIO), Høgskoleveien 8, 1433, Ås, Norway.