Abstract: Based on the 1983〖KG-*2〗-〖KG-*7〗2004 observation data of phenophas e and air temperature in Zhengzhou, the spring phenophase changes of four tree s pecies and two herb species in the City as well as their relationships with air temperature change were studied. Since 1983, there had been an advancing tendenc y of the spring phenophase of the dominant plants in Zhengzhou, with the charact eristics of synchronization and sequentiality. There was a significant correlati on between the first flowering dates of dominant plants and the mean air tempera ture from March to April, and for Populus tomentosa and Salix babylonica , their first flowering dates also had significant correlations with the mean ai r temperature in winter. The first flowering dates of the dominant plants advanc ed with increasing mean air temperature from March to April. With an increase of 1 ℃, the first flowering dates of Robinia pseudoacacia, S. babylonica, Tar axacum mongolicum, and Plantago asiatica advanced 417, 369, 816, and 130 days, respectively. The 4 ten-days before first flowering of the dominan t plants were the most sensitive period of time to air temperature change.

Key words: Tree species diversity, Tropical montane rain forest, Xishuangbanna