| [key problems in ecological research on vegetations in northeast china]. | there exist many controversial problems in ecological research on vegetations in northeast china, in spite of systemic studies for half century. in this paper, some comments were put forward on the recent researches of our concerned problems: 1) the zonal distribution pattern of vegetations in northeast china could be quantificationally explained according to kira's warmth index (wi), coldness index (ci), and xu wenduo's humidity index (hi). 2) there exists tundra vegetation in the north of daxi ... | 2004 | 15624797 |