1. Key Lab. of Mountain Surface Processes and Ecological Regulation; Institute of Mountain Hazards and Environment Chinese Academy of Sciences; No. 9, Block 4, South Renmin Rd. Chengdu 610041 China
2. Dep. of Renewable Resources; 442 Earth Sciences Building Univ. of Alberta Edmonton AB T6G 2E3 Canada
3. Northern Forestry Centre Canadian Forest Service; 5320 122nd St. Edmonton AB T6H 3S5 Canada
4. Biometeorology and Soil Physics Group Faculty of Land and Food Systems; Univ. of British Columbia; Vancouver BC V6T 1Z4 Canada
5. Canadian Wood Fibre Centre; Edmonton AB T6H 3S5 Canada