极端高温对黄淮海平原冬小麦产量的影响

Impacts of Extreme High Temperature on Winter Wheat Yield in the Huang-Huai-Hai Plain

以黄淮海平原冬小麦为研究对象,选择极热天数和极端生长度日作为极端高温指标,采用气候倾向率法分析冬小麦生长季极端高温的时空变化分布规律;基于一阶差分法建立一般生长度日、极端生长度日和降水与冬小麦产量的多元线性回归模型,从县级、省级和区域3个尺度分析冬小麦产量对极端高温的敏感性,阐明近29 a极端高温对冬小麦产量变化的贡献程度。结果表明,1980—2008年,黄淮海平原冬小麦生长季的极端高温有加剧趋势,且空间上自东向西逐渐加重。在县级、省级和区域尺度极端生长度日对冬小麦产量均呈明显的负效应。淮河以北地区大部分县市的极端高温对冬小麦具有明显的减产效应。天津市和河南省冬小麦受极端高温影响严重,分别减产4.15%和1.49%。近29 a来黄淮海平原北部与南部区域冬小麦生长季极端生长度日的增加分别导致冬小麦减产0.72%和0.65%。因此,过去几十年的极端高温不利于黄淮海平原冬小麦的生长发育。

So far little has been reported on impacts of extremely high temperature on yield of winter wheat. Currently astudy was conducted in the HuangHuaiHai Plain, a major wheat producing region of the country, using the number of extremely hot days and the number of extreme growing degree days as indicators of extremely high temperature to explore spatiotemporal variation of extremely high temperature during the winter wheat growing seasons, with the climate tendencyrate method. And a multifactor linear regression model encompassing the number of normal growing degree days, the number of extreme growing degree days, precipitation, and winter wheat yield was established with the first difference methodand used to analyze sensitivity of winter wheat in yield to extremely high temperature on the county, province and regionscales and further to illustrate contribution of extremely high temperature to winter wheat yield during the 29 years from1980 to 2008. Results show that during the 29 years, extremely high temperature displayed a rising trend and spatially fromeast to west a rising trend too, and the number of extreme growing degree days had a significantly negative effect on winterwheat yield, on all the three scales. Extremely high temperature during the winter growing season was found to have an obvious yieldreducing effect on winter wheat in the region north to the Huai River, specially in Tianjin and Henan Province,where the yield of winter wheat decreased by 4 15% and 1 49%, respectively. In the northern and southern parts of theHuangHuaiHai Plain, the increasing number of extreme growing degree days caused a drop of 0 72% and 0 65% in winter wheat yield during the period. Obviously extremely high temperature affects negatively growth and production of winterwheat in the region.