| 摘要: |
| ［目的］气候变化可能通过影响生育期的长度，对冬小麦遭受倒春寒的风险产生增强或减弱的双重可能影响。文章结合冬小麦生育期的变化，研究分析气候变化背景下冬小麦在不同生育期内遭遇倒春寒风险的时空变化特征。［方法］利用北方冬小麦主产区地面气象台站记录的逐日气温资料以及农业气象台站记录的地面物候资料，提取出各气象站点在1993—2016年发生在返青—拔节、拔节—抽穗以及抽穗后的倒春寒事件，计算倒春寒气象指标K，结合核密度分析及联合经验正交分析（JEOF）方法，分析冬小麦在不同生育期内遭遇倒春寒强度的时空变化规律。［结果］（1）1993—2016年在返青—拔节以及拔节—抽穗阶段，倒春寒累积K值与发生次数均有减少的趋势，但在抽穗后阶段，倒春寒累积K值减少速度最慢，且发生次数小幅度增加； （2）生育期长度与累积K值有较好的时空变化一致性，生育期的延长往往伴随着累积K值增加，但在不同区域、不同生育阶段生育期长度变化的作用存在差异； （3）在返青—拔节、拔节—抽穗阶段，倒春寒高发聚集区范围不断缩小北移，在抽穗后阶段，高发聚集区覆盖范围广，且空间分布变化不明显。［结论］未来全球气温升高对减弱倒春寒的发生强度有正面效应，但这种正面效应也可能被生育期延长以及小麦抗病虫害能力减弱带来的负面影响所抵消。因此，仍应加强对倒春寒的预警与防御，尤其需要重点关注抽穗后阶段。 |
| 关键词: 气候变化倒春寒北方冬小麦关键生育期时空特征 |
| DOI： |
| 分类号:K90 |
| 基金项目:国家重点研发计划项目“区域尺度气候变化对小麦生产系统的综合影响评价研究”（2017YFD0300201） |
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| SPATIOTEMPORAL CORRELATION BETWEEN SPRING FROST AND GROWTH PERIOD IN MAIN WHEAT PRODUCING AREAS IN NORTHERN CHINA |
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Zhang Luyun1, Wang Shuai1, Wang Wenqing1, Chen Jin1,2,3, Cui Xihong1,2,3※
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1. Institute of Remote Sensing Science and Engineering, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China；2. State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China；3. Beijing Engineering Research Center for Global Land Remote Sensing Products, Faculty of Geographical Science, Beijing 100875, China
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| Abstract: |
| Climate change could have the dual potential effect of enhancing or weakening the risk of winter wheat suffering from spring frost by affecting the length of the growing period. To understand the spatiotemporal pattern of spring frost during different growth periods in the main wheat producing areas in North China, we extracted the spring frost events and the cumulative K value for the periods of turning green to jointing, jointing to heading, and heading to post heading stage, respectively, based on daily temperature data and ground phenological records. Based on this, the spatiotemporal characteristics of frost risk were analyzed in the context of climate change from 1993 to 2016. The results showed that (1)Both the cumulative K value and frost occurrences tended to decrease in the periods between turning green to jointing and jointing to heading. However, at post heading stage, the cumulative K values decreased the slowest, while the frost occurrences increased slightly; (2)There was a good consistency in spatiotemporal changes between the length of growth period and the accumulated K value. The extension of growth period was often accompanied by the increase of cumulative K value. However, the role of changes in growth period varies across regions and phenological stages; (3)The high frost incidence area shrank and shifted northward in the periods of turning green to jointing and jointing to heading. At post heading stage, the high frost incidence area covered a wide range without significant changes in spatial distribution. The global rising temperature in the future will have a positive effect on reducing the occurrence and intensity of spring frost, but this positive effect may also be offset by the negative impact of advanced phenological stages and the weakened wheat resistance to disease and pest. Therefore, the early warning and defense of spring frost disaster still need to be strengthened, especially at the post heading stage of winter wheat. |
| Key words: climate change spring frost North winter wheat key growth period spatiotemporal characteristics |
