北京山桃开花期变化及其气候影响因子分析

为了给植被开花期预报和气候变化的生态影响评估提供科学依据,笔者利用1951—2004年北京颐和园山桃开花期观测资料,分析山桃开花期年际、年代际变化和影响其的气候因子。结果表明:山桃多年平均开花期为3月26日,年际间呈显著提前趋势。山桃开花期的转折点在1980s,1980s后呈显著提前趋势(P<0.01),较1950s—1970s平均提前6天。山桃10年平均、最晚、最早开花期均显著提前,尤其是2000年以后山桃的平均、最晚、最早开花期,较1951—1990年分别提前14天、14天、16天。影响山桃开花期时间最主要的是从当年1月1日到山桃开花期的平均气温。1980s开始影响山桃开花期显著提前的主要气候因子是时间段内（冬、春季）平均气温的升高。

Blooming Change and Its Climate Impact Factors of Prunus davidiana in Beijing

To provide a basis for the forecast of blooming stage and the ecological impact assessment of climate change, based on the observation data of Prunus davidiana at blooming stage in the Summer Palace in Beijing from 1951 to 2004, we analyzed the interannual and inter-decadal change of the blooming period of Prunus davidiana and the influencing climate factors. The results showed that: the average blooming date of Prunus davidiana was March 26, and there was a significant advance trend among the years; the turning point of the blooming period of Prunus davidiana was in 1980s, with a significant advance trend (P<0.01) after 1980s, which was 6 days earlier during 1980s-2000s than that during 1950s-1970s; the average, latest and earliest blooming period of Prunus davidiana of 10 years were all significantly advanced, especially after 2000, 14 days, 14 days and 16 days earlier, respectively, compared with those of 1951-1990; the average air temperature from 1 January to the blooming period was the main factor affecting the blooming date of Prunus davidiana; the increase of average air temperature (in winter and spring) before blooming was the main climate factor which significantly promoted the blooming of Prunus davidiana after 1980s.