1. State Key Lab. of Vegetation and Environmental Change; Institute of Botany, Chinese Academy of Sciences; 20 Nanxincun Xiangshan Beijing 100093 China
2. Institute of Atmospheric Environment China Meteorological Administration; Shenyang 110016 China
3. Asian Environment Research Group; National Institute for Environmental Studies (NIES); 16-2 Onogawa Tsukuba Ibaraki 305-8506 Japan