Hot spots of wheat yield decline with rising temperatures
Hot spots of wheat yield decline with rising temperatures
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DOI：
10.1111/gcb.13530
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发表时间：
2017-06-01
影响因子：
11.6
通讯作者：
Lobell, David B.
中科院分区：
文献类型：
--
作者：
Asseng, Senthold;Cammarano, Davide;Lobell, David B.
世界上许多春麦灌溉区也是高度贫困地区。气温升高对高度贫困地区小麦产量的影响尚不确定。使用来自两个关键春小麦灌溉区（印度和苏丹）的多模型集成构建了与模型不确定性量化相结合的谷物产量-温度响应函数，并将其应用于世界上所有春小麦灌溉区。印度南部和巴基斯坦南部的小麦种植区因气温升高而产量大幅下降，同时贫困人数也很高，这表明这些地区是未来粮食安全的“热点”。多模型模拟产生了产量随温度升高而线性绝对下降的结果，不确定性随某个位置的参考温度而变化。由于绝对单产呈线性下降，低产环境下（例如印度南部、巴基斯坦南部和所有苏丹小麦种植区的高参考温度地区）相对单产下降幅度更大，这些地区的农民将受到气温升高的最严重打击。然而，由于低产和高产地区的绝对单产下降幅度大致相同，因此在高产环境（例如印度北部）中，气温升高对国家产量的贡献赤字更高，因为这些环境对国家小麦产量的贡献更大。尽管如果有灌溉，苏丹可能会种植更多小麦，但由于参考温度较高，粮食产量将会较低，而未来气温的升高将进一步限制产量。
Many of the irrigated spring wheat regions in the world are also regions with high poverty. The impacts of temperature increase on wheat yield in regions of high poverty are uncertain. A grain yield-temperature response function combined with a quantification of model uncertainty was constructed using a multimodel ensemble from two key irrigated spring wheat areas (India and Sudan) and applied to all irrigated spring wheat regions in the world. Southern Indian and southern Pakistani wheat-growing regions with large yield reductions from increasing temperatures coincided with high poverty headcounts, indicating these areas as future food security 'hot spots'. The multimodel simulations produced a linear absolute decline of yields with increasing temperature, with uncertainty varying with reference temperature at a location. As a consequence of the linear absolute yield decline, the relative yield reductions are larger in low-yielding environments (e.g., high reference temperature areas in southern India, southern Pakistan and all Sudan wheat-growing regions) and farmers in these regions will be hit hardest by increasing temperatures. However, as absolute yield declines are about the same in low-and high-yielding regions, the contributed deficit to national production caused by increasing temperatures is higher in high-yielding environments (e.g., northern India) because these environments contribute more to national wheat production. Although Sudan could potentially grow more wheat if irrigation is available, grain yields would be low due to high reference temperatures, with future increases in temperature further limiting production.