Abstract:Temperature sensitivity (ST) of the leaf unfolding date (LUD), which was defined as the shift of LUD per unit change in preseason temperature, was widely used to quantify phenological response to climate change. Species whose LUD responding to temperature more sensitively tended to have an earlier growing season, thus occupying more resources and obtaining competitive advantages in the community. Therefore, ST could be used to assess the ability of species to cope with climate change. The temporal change in ST and their driving forces have been studied for several plant species in Europe, but the long-term variation of ST in China is still unclear. In this study, we selected the LUD data for 163 woody plants at 10 sites in China from the China Phenology Observation Network (CPON), as well as the corresponding meteorological data from the China Meteorological Data Service Center. First, ST was calculated as the slope of the regression between LUD and the mean temperature during the optimum preseason, for each 15-year moving window during the period 1963-2014 for each species at each site. Second, we analyzed the temporal trends in ST and calculated the average trend of ST for each site to test the spatial patterns of ST. Finally, we discussed the possible reasons for the changes in ST. The conclusions were as follows:(1) Out of 313 LUD time series, 60.1% displayed increasing ST, with 40.0% significantly (P < 0.05). ST for the other 39.9% of time series exhibited a decreasing trend, with 28.4% significantly. (2) In terms of the spatial patterns, ST of LUD showed increasing trends at 6 sites of temperate region. The most obvious one was Beijing, with 75% of species exhibiting significantly increasing ST. On the contrary, ST of LUD decreased over the past several decades at 4 sites of subtropical region except for Hefei. The most obvious one was Changsha, with 68.4% of species exhibiting significantly decreasing ST. (3) Both the winter chilling and spring temperature variance affected the temporal variation in ST. Reduced chilling days could lead to a lower ST, while lower spring temperature variance could lead to a higher ST.