Responses of Spring Phenology to Climate Changes in Beijing in Last 150 Years

Based on the calculation of six plant phenology in spring in Beijing,a expresentative index of spring phenology,was used to analyze response model of plant phenology to temperature changes.According to changing trends of temperature,temperature and phenology data in historical periods were categorized to four series with the same length of time slice.Prominence differences of two series were verified by u-test.Response model and mechanisms of phenophase on temperature changes were analyzed in different series with different models of temperature changes.It had been concluded that the response of phenophase advance or delay to temperature change was nonlinear.At the same amplitude of temperature change,phenophase delay amplitude caused by temperature decrease was less than phenophase advance amplitude caused by temperature increase;If the temperature increased 1℃,spring phenophase in Beijing would advance 2.8-3.6 days.