How climate change will affect overwintering crops is largely unknown due to the complex and understudied interactions among temperature, rainfall and snowpack. Increases in average winter temperature should release cold limitations yet warming-induced reductions of snowpack thickness should lead to decreased insulation effects and more exposure to freezing. Here, using statistical models, we show that the presence of snowpack weakens yield sensitivity to freezing stress by 22% during 1999–2019. By 2080–2100, we project that reduced snow cover insulation will offset up to one-third of the yield benefit (8.8 ± 1.1% for RCP 4.5 and 11.8 ± 1.4% for RCP 8.5) from reduced frost stress across the United States. Furthermore, by 2080–2100 future decline in wheat growing season snowfall (source of snowmelt) will drive a yield loss greater than the yield benefit from increasing rainfall. Explicitly considering these factors is critical to predict the climate change impacts on winter wheat production in snowy regions.

由于温度、降雨和积雪之间的相互作用复杂且研究不足，气候变化将如何影响越冬作物在很大程度上是未知的。冬季平均温度的升高应该会释放寒冷的限制，而变暖引起的积雪厚度的减少应该会导致隔热效果降低和更多地暴露于冰冻中。在这里，我们使用统计模型表明，在 1999 年至 2019 年期间，积雪的存在使产量对冻应力的敏感性降低了 22%。我们预计，到 2080 年至 2100 年，减少的积雪保温将抵消美国减少霜冻应力带来的高达三分之一的收益收益（RCP 4.5 为 8.8 ± 1.1%，RCP 8.5 为 11.8 ± 1.4%）。此外，到 2080-2100 年，小麦生长季节降雪（融雪来源）的未来下降将导致产量损失大于降雨增加带来的产量收益。明确考虑这些因素对于预测气候变化对雪区冬小麦生产的影响至关重要。