Abstract: The sensitivity and sensitive periods of leaf unfolding dates of woody plant to climate change in China's eastern monsoonal region were analyzed.Four tree species(Salix babylonica L.,Hibiscus syriacus L.,Robinica pseudoacacia L.,Firmiana platanifolia(Linn.f.) Marsili) in China's different sites for variation of leaf unfolding dates in response to variability of temperature in spring were investigated.Phenological and meteorological data from 1963 to 1988 were examined using unitary correlation.The results showed that leaf unfolding dates became significantly earlier and the interannual variation increased with the latitude.The periods during February and April were the significant sensitive periods of leaf unfolding dates to temperature in spring,which were shorter in the north area(10-40 days) and longer in the south area(40-60 days).The correlations between leaf unfolding dates and spring temperature were significantly negative.The sensitivities of leaf unfolding dates to temperature in the south area(3.3-9.0 days/℃) were higher than that in the north area(1.6-5.6 days/℃).The sensitivities of leaf unfolding dates to climate change were different for specific species and different regions.

Key words: Woody plant, Woody plant, Leaf unfolding date, Climate change, Sensitivity, Spring Temperature