寿光1961—2015年初、终霜日、无霜期变化特征 及对农业的影响

笔者利用寿光市1961—2015年的气候资料，通过对初、终霜日期、无霜期观测资料，利用现代气候诊断分析方法，分析寿光市初、终霜日期、无霜期变化特征，科学评估初、终霜日变化对冬小麦和棉花产量的影响，为寿光农业生产防灾减灾提供参考依据。结果表明，（1）初霜日总体呈推迟趋势,终霜日呈提早趋势,无霜期延长。（2）初霜日呈推迟趋势，气候倾向率为2.23 d/10 a，1991年初霜日发生突变；（3）终霜日呈提前趋势，气候倾向率为-1.35 d/10 a。（4）无霜期日数呈增多趋势，气候倾向率为3.58 d/10 a，1994年无霜期日数发生突变。（5）初霜日和无霜期与小麦和棉花产量呈正相关，终霜日与小麦和棉花产量呈负相关，初霜日推迟比终霜日提前对小麦和棉花的产量贡献大。

First, Last Frost Dates and Frost-free Period During 1961-2015 in Shouguang: Variation Characteristics and Its Effect on Agriculture

The paper aims to provide reference for disaster prevention and mitigation of agricultural production in Shouguang, based on the climatic data (first, last frost date and frost-free period) from 1961 to 2015 in Shouguang by using modern climate diagnostic analysis method, we analyzed the variation characteristics of first, last frost date and frost-free period, and evaluated the influence of first, last frost date on yield of winterwheat and cotton. The results showed that: (1) first frost date showed a delayed trend, but last frost date was ahead of time, leading to an increase in frost-free period; (2) first frost date was postponed and the climate trend rate was 2.23 d/10 a, a mutation existed in 1991; (3) last frost date was advanced with the tendency rate of -1.35 d/10 a; (4) frost-free period increased with the tendency rate of 3.58 d/10 a and had a mution in 1994; (5) first frost day and frost-free period were positively correlated with the yield of wheat and cotton, and last frost date was negatively correlated with the yield of wheat and cotton, and the delay of first frost day made more contribution to the yield of wheat and cotton than that of the advacing of last frost day.