Abstract: | The relation between distribution of edificator and companion in zonal vegetation and water-temperature condition in the Northeast China was studied based on the method of Kira’s warmth index (WI), coldness index (CI) and the humidity index (HI) proposed by the author. The results are as follows: 1. The whole range, optimum range of warmth index and the value of humidity indexes of 40 species in the Northeast China have been determined. 2. The 40 species are divided into the six groups according to their warmth index. The species of each group have the same range of warmth index. 3. The upper limit of the forest in Changbai Mountain is in 2100 m above sea level, the WI value of which is 15 ℃·month. 4. The border line between the coniferous forest in the cold-temperate zone and the mixed coniferous-broad leaves forest in the temperate zone has the WI value of 45 ℃·month. The border line between the mixed coniferous-broad leaves forest in the temperate zone and the deciduous broad leaves forest in the warm-temperate zone has the WI value of 85 ℃·month. The border line between the forest and the grassland has the HI value of 7.5 mm/℃·month. The border line between the forest, grassland and the steppe has the HI value of 5.2 mm/℃·month. |