1. Department of Forest and Conservation Sciences; Faculty of Forestry; Forest Sciences Centre; University of British Columbia; Vancouver BC V6T 1Z4 Canada
2. Department of Dendrology and Forest Tree Breeding; Faculty of Forestry and Wood Sciences; Czech University of Life Sciences; Prague 165 21 Czech Republic
3. Scion (New Zealand Forest Research Institute Ltd); Whakarewarewa Rotorua 3046 New Zealand
4. Department of Wood Science; Faculty of Forestry; Forest Sciences Centre; University of British Columbia; Vancouver BC V6T 1Z4 Canada