Abstract: Based on phenological records extracted from Chinese historical dairies, the series of spring phenodate in the Yangtze River Delta region of China since 1834 is reconstructed. Together with the temperature and phenology observation data, the interpretation of the phenodate variation to temperature change is also analyzed. The results are shown as follows. (1) Spring phenology in the Yangtze River Delta region is gradually delayed during 1834-1893 and greatly advances after 1893; and exhibits inter-decadal fluctuation during 1900-1990 and greatly advances after 1990. The latest year of the spring phenodate is delayed by 27 days and occurs in 1893, while the earliest year is advanced by 17 days and occurs in 2007. (2) Correlation coefficient between spring phenodate in the Yangtze River Delta region and temperature (previous December to March and January to March) is higher significant up to the level at 99.9% with the value over -0.75 and -0.80, respectively. The variation of spring phenodate well indicates the change of temperature from previous winter to early spring, especially from January to March. These results will provide a data basis for the further study on temperature change reconstruction using multi-proxy data, including phenological records during historical times.

Key words: historical dairies, spring phenodate, change, Yangtze River Delta region, past 150 years