1. Center for Health and Bioresources, Bioresources Unit, Konrad Lorenz Straße 24 AIT Austrian Institute of Technology Tulln A‐3430 Austria
2. INRAE Univ. Bordeaux, BIOGECO Pessac F‐33600 France
3. Natural Resources Canada Canadian Forest Service, Laurentian Forestry Centre Québec G1V4C7 Canada