北京地区东京樱花花期对气候变化的分段响应

Responses of flowering date of Cerasus yedoensis to climate change in different periods in Beijing

基于1965—2014年北京颐和园观测的东京樱花(Cerasus yedoensis)始花期数据和同期日均气温资料,运用相关、回归分析法和M-K突变检验法分析了北京地区东京樱花始花期对气候变化的分段响应情况。结果表明:1965—2014年间,北京地区东京樱花始花期总体呈现显著提前趋势,且于1990年发生了突变。1990—2014年的平均始花期较1965—1989年提前了10 d。始花期与2—4月气温最为相关,气温的敏感度总体为-4. 1 d/℃。对比1990年前后两个时段东京樱花始花期的气温敏感度,发现1990年后始花期的气温敏感度有所增加,从-2. 9 d/℃增至-4. 6 d/℃。根据时空物候模型分析,后一时段樱花开花当日温度相对较低,积温累积的时间也相对较长,这是导致樱花始花期气温敏感度在后一时段较高的直接原因。

According to the mean daily temperature data and the data of the First Flowering Date(FFD) of Cerasus yedoensis in Beijing Summer Palace from 1965 to 2014, the paper analyses the response of FFD of Cerasus yedoensis to climate change in different period by using correlation analysis, regression analysis and M-K mutation test. The results show that FFDs have advanced significantly for the past 50 years and a mutation occurred in 1990. The average FFD from 1990 to 2014 have been advanced by 10 days compared with that from 1965 to 1989. The temperature from February to April most significantly influences the FFD, and the overall FFD sensitivity to temperature is -4.1 d/℃. The temperature sensitivity of FFD during the latter period (1990-2014) is shown to be higher than during the former period(1965-1989), increasing from -2.9 d/℃ to -4.6 d/℃. Based on the spatio-temporal phenological model, the temperature of the very days of FFD in the latter period is relatively low, and the time of temperature accumulation is relatively long, which is the direct cause of the higher temperature sensitivity of FFD in the latter period.