ABSTRACT: Russia has become the foremost wheat exporting country worldwide. Episodic production breakdowns caused by extreme weather during sensitive stages of crop development are hence of concern not only for the domestic but also for the global wheat market. In this study, we examine heat stress occurrence and availability of rainwater during the flowering period, and investigate their impacts on the winter and spring wheat yields of 3 major production areas of Russia. We also consider the role of atmospheric blocking as a precursor of extreme weather, and assess the correlation between blocking duration and yield. Owing to the later occurrence of flowering in spring wheat and the warmer climate of southern European Russia, we find the probability of heat stress to be higher in spring than in winter wheat, and higher in the south than in the north of the study area. For spring wheat, the negative association between yield and heat stress is stronger than the positive association between yield and total precipitation. The reverse is true for winter wheat. In all regions and for both wheat types, heat stress occurrence and total precipitation amounts correlate significantly with the area-weighted average number of blocked days. We also find a correlation between blocking duration and yield, but results are significant only for spring wheat.

中文翻译：

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俄罗斯冬小麦和春小麦的生产力，开花期的高温胁迫和干旱状况以及大气阻塞的作用

摘要：俄罗斯已成为世界上最重要的小麦出口国。因此，在作物发展的敏感阶段，极端天气造成的突发性产量下降不仅引起国内小麦市场的关注，而且也引起全球小麦市场的关注。在这项研究中，我们研究了开花期热应激的发生和雨水的可用性，并研究了它们对俄罗斯3个主要产区的冬小麦和春小麦产量的影响。我们还考虑了大气阻塞作为极端天气先兆的作用，并评估了阻塞持续时间与产量之间的相关性。由于春季小麦开花的后期发生以及俄罗斯南部欧洲气候变暖，我们发现春季热应激的可能性高于冬季小麦，并且在研究区域的南部高于北部。对于春小麦，产量与热应力之间的负相关要强于产量与总降水量之间的正相关。冬小麦则相反。在所有地区和两种小麦类型中，热应力的发生和总降水量与区域加权平均阻塞天数显着相关。我们还发现阻塞持续时间与产量之间存在相关性，但结果仅对春小麦有意义。热应力的发生和总降水量与区域加权平均阻塞天数显着相关。我们还发现阻塞持续时间与产量之间存在相关性，但结果仅对春小麦有意义。热应力的发生和总降水量与区域加权平均阻塞天数显着相关。我们还发现阻塞持续时间与产量之间存在相关性，但结果仅对春小麦有意义。