[1] Northeast Forestry Univ, Ctr Ecol Res, Harbin 150040, Peoples R China
[2] Northeast Forestry Univ, Key Lab Sustainable Forest Ecosyst Management, Minist Educ, Harbin 150040, Peoples R China
[3] No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA