气候变化背景下中国不同区域玉米生育期高温胁迫时空变化特征

Spatiotemporal variation of high temperature stress in different regions of China under climate change

研究气候变化背景下作物生长季高温热害的时空分布和变化特征,对于制定适应气候变化的作物栽培管理技术有重要的参考意义。本研究利用我国558个气象站点的逐日气象数据和物候期数据,分析了1961—2020年玉米不同生育阶段的高温度日(heat degree days,HDD)及其气候倾向率的时空变化特征。结果表明,1961—2020年,我国玉米全生育期及各生育阶段的HDD整体呈升高趋势,不同农作区玉米全生育期HDD增加1.19~9.27℃d(10a)^(-1),四川盆地农作区、华南农林渔区和西北农牧区增幅较高,分别显著增加8.79、9.27和5.81℃d(10a)^(-1)。不同生育阶段HDD变化趋势呈现明显区域差异,北方农作区玉米HDD在生育前期增幅较大,而南方农作区玉米HDD在生育后期增幅较大。播种-抽穗期,北方农作区中西北农牧区和北部中低高原农牧区HDD分别显著增加2.67℃d(10a)^(-1)和2.00℃d(10a)^(-1),黄淮海平原农作区增加1.41℃d(10a)^(-1),都高于其他农作区。抽穗至乳熟期,南方农作区的HDD增幅较大,华南农林渔区和四川盆地农作区HDD分别显著增加3.68℃d(10a)^(-1)和2.11℃d(10a)^(-1)。乳熟至成熟期,南方农作区HDD增幅为0.88~5.31℃d(10a)^(-1),大幅超过北方农作区的-0.01~0.59℃d(10a)^(-1)。因此,为应对不断增加的玉米高温胁迫风险,北方玉米产区应重点关注播种-乳熟期高温对玉米生产的影响,南方玉米产区应重点关注抽穗后高温对玉米生产的影响。

Analysing the spatial-temporal distribution and the change of high temperature damage during crop growth period is of great significance for developing management techniques of crop cultivation under climate change.Based on the daily data of 558 meteorological stations and maize phenology period in China,we explored the spatiotemporal variation of heat degree days(HDD)and its trend of different maize growth periods from 1961 to 2020.The results showed that the HDD exhibited a general increased trend during the whole growth period and every growth stage of maize in China from 1961 to 2020,with HDD increased 1.19-9.27℃d(10a)^(-1)of different farming regions.The HDD increase range was higher in Sichuan Basin farming region,south China farming region and northwest farming region,and it increased significantly by 8.79,9.27,and 5.81℃d(10a)^(-1),respectively.The change trend of HDD at different growth stages had obvious variation in different regions.HDD increased greatly in the early growth period of northern farming regions,while HDD increased greatly in late growth period of southern farming regions.During maize sowing-tassel period,the HDD increased significantly by 2.67 and 2.00℃d(10a)^(-1)in northwest farming region and north China farming region,respectively,and it increased by 1.41℃d(10a)^(-1)in Huang-Huai-Hai farming region,both of them were higher than that in other farming regions.During tassel-milk period,the HDD of southern farming regions increased greatly,which increased significantly by 3.68 and 2.11℃d(10a)^(-1)in south China farming region and Sichuan Basin farming region,respectively.During milk-maturity period,the HDD of southern farming regions increased higher by 0.88-5.31℃d(10a)^(-1)than-0.01-0.59℃d(10a)^(-1)in northern farming regions.In conclusion,to cope with the increasing risk of high temperature stress of maize,northern farming regions should focus on the impact of high temperature during maize sowing-milk period,and southern farming regions should focus on the impact of high temperature after maize tasseled.