气候变化背景下中国玉米产区开花期高温时空分布特征

Spatial-Temporal Variations of High Temperature During Flowering Period in Maize-Producing Areas of China Under Climate Change

【目的】全球气候变暖背景下,极端高温频发将会对农作物生产造成潜在威胁,因此,基于多种高温指标综合评估作物生长季高温时空分布特征对制定有效的灾害风险管理和适应措施至关重要。【方法】以我国玉米潜在种植区为研究区域,基于第六次国际耦合模式比较计划(Coupled Model Intercomparison Project,CMIP6)中2个共享社会经济情景(Shared Socioeconomic Pathways,SSP1-2.6和SSP5-8.5)下1981—2060年的逐日最高气温资料和玉米生育期资料,分析了基准时段(1981—2014年)和未来(2015—2060年)玉米开花期高温强度(HSI)、高温持续时间(AHSD)和累积高温度日(HDD)的时空变化特征。【结果】1981—2014年玉米开花期HSI、AHSD、HDD在黄淮海夏玉米区和西北灌溉玉米区最大(区域均值分别为32.3和33.8℃、8.4和9.8 d、22.9和40.3℃·d)。受气候变暖影响,未来气候情景下,特别是在SSP5-8.5气候情景下,我国玉米开花期高温发生范围扩大、强度增加,HSI和AHSD增加最大的区域为北方春播玉米区,SSP1-2.6和SSP5-8.5情景下,HSI的增加趋势分别为0.97和1.16℃·(10a)^(-1),AHSD的增加趋势分别为0.73和1.11 d·(10a)^(-1)。全区HDD增加最大的区域为黄淮海夏玉米区,SSP1-2.6和SSP5-8.5情景下增加趋势分别为2.68和5.26℃·d·(10a)^(-1)。【结论】未来我国玉米开花期高温发生范围将扩大、强度将增加;且应重点关注黄淮海夏玉米区和北方春播玉米区的开花期高温,前者主要由于基础温度高,后者主要由于增温幅度较大。可通过选用抗高温品种、调整播种窗口、采用水肥及化学调控等综合措施降低高温威胁。

【Objective】Under the background of global warming,the frequent occurrence of extreme high temperature would threaten crop production greatly.Therefore,the spatial-temporal variations of high temperature during crop growth period based on several heat stress index were cleared,which was crucial for developing effective disaster risk management and adaptation measures.【Method】In this study,the maize potential planting area was focused on.Based on the daily maximum temperature data from 1981 to 2060 in two Shared Socioeconomic Pathways scenarios(SSP1-2.6 and SSP5-8.5)of Coupled Model Intercomparison Project Phase 6(CMIP6)and maize phenology data,we analyzed the spatial distribution and temporal trend of the heat stress intensity(HSI),accumulated heat stress days(AHSD),and heat degree-days(HDD)during flowering period of maize in the baseline period(1981-2014)and future period(2015-2060).【Result】From 1981 to 2014,the HSI,AHSD and HDD during the flowering period of maize were the largest in Huang-Huai-Hai(HHH)and Northwest China(NWC),with the average value of 32.3 and 33.8℃,8.4 and 9.8 d,22.9 and 40.3℃·d,respectively.Due to climate warming,the high temperature during the flowering period of maize in China was characterized by long duration and wide range under the two climate scenarios,especially in SSP5-8.5.The largest temporal trend of HSI and AHSD occurred in Northern China(NC),under SSP1-2.6 and SSP5-8.5.The increasing trend of HSI were 0.97 and 1.16℃·(10a)-1,and the increasing trend of AHSD were 0.73 and 1.11 d·(10a)-1.The largest temporal trend of HDD occurred in HHH,under SSP1-2.6 and SSP5-8.5,with the increasing trend of 2.68 and 5.26℃·d·(10a)-1.【Conclusion】In the future,the high temperature during the flowering period of maize in China was characterized by long duration and wide range,especially for HHH and NC.The former was mainly due to the high base temperature,and the latter was due to the large warming trend.The loss caused by high temperature could be reduced by selecting high temperature resistant varieties,adjusting the sowing window,adopting water,fertilizer,and chemical management measures.