Comparing outputs of multiple climate and crop models is an option to assess the uncertainty in simulations in a changing climate. The use of multiple wheat models under five plausible future simulated climatic conditions is rarely found in literature. CERES-Wheat, DSSAT-Nwheat, CROPSIM-Wheat, and APSIM-Wheat models were calibrated with observed data form eleven sowing dates (15 October to 15 March) of irrigated wheat trails at Faisalabad, Pakistan, to explore close to real climate changing impacts and adaptations. Twenty-nine GCM of CMIP5 were used to generate future climate scenarios during 2040–2069 under RCP 8.5. These scenarios were categorized among five climatic conditions (Cool/Wet, Cool/Dry, Hot/Wet, Hot/Dry, Middle) on the basis of monthly changes in temperature and rainfall of wheat season using a stretched distribution approach (STA). The five GCM at Faisalabad and Layyah were selected and used in the wheat multimodels set to CO2 571 ppm. In the future, the temperature of both locations will elevate 2–3 °C under the five climatic conditions, although Faisalabad will be drier and Layyah will be wetter as compared with baseline conditions. Climate change impacts were quantified on wheat sown on different dates, including 1 November, 15 November, and 30 November which showed average reduction at semiarid and arid environment by 23.5%, 19.8%, and 31%, respectively. Agronomic and breeding options offset the climate change impacts and also increased simulated yield about 20% in all climatic conditions. The number of GCMs was considerably different in each quadrate of STA, showing the uncertainty in possible future climatic conditions of both locations. Uncertainty among wheat models was higher at Layyah as compared with Faisalabad. Under Hot/Dry and Hot/Wet climatic conditions, wheat models were the most uncertain to simulate impacts and adaptations. DSSAT-Nwheat and APSIM-Wheat were the most and least sensitive to changing temperature among years and climatic conditions, respectively.

中文翻译：

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巴基斯坦采用多种气候和作物模型对小麦的气候变化影响和适应

比较多个气候和作物模型的输出是评估气候变化模拟中的不确定性的一种选择。在五种可能的未来模拟气候条件下使用多种小麦模型在文献中很少见。CERES-Wheat、DSSAT-Nwheat、CROPSIM-Wheat 和 APSIM-Wheat 模型使用来自巴基斯坦费萨拉巴德灌溉小麦径的 11 个播种日期（10 月 15 日至 3 月 15 日）的观测数据进行校准，以探索接近真实的气候变化影响和适应。CMIP5 的 29 个 GCM 用于根据 RCP 8.5 生成 2040-2069 年期间的未来气候情景。根据小麦季节的月度温度和降雨量变化，使用拉伸分布方法 (STA)，将这些情景分为五种气候条件（冷/湿、冷/干、热/湿、热/干、中）。Faisalabad 和 Layyah 的五个 GCM 被选择并用于设置为 CO2 571 ppm 的小麦多模型。未来，在五种气候条件下，两个地点的温度都将升高 2-3°C，尽管与基线条件相比，费萨拉巴德会更干燥，莱耶会更潮湿。气候变化对不同日期播种的小麦的影响进行了量化，包括 11 月 1 日、11 月 15 日和 11 月 30 日，在半干旱和干旱环境中平均减少了 23.5%、19.8% 和 31%。农艺和育种选择抵消了气候变化的影响，并在所有气候条件下将模拟产量提高了约 20%。GCM 的数量在 STA 的每个方格中都有很大不同，表明两个地点未来可能的气候条件存在不确定性。与费萨拉巴德相比，Layyah 小麦模型的不确定性更高。在热/干和热/湿气候条件下，小麦模型在模拟影响和适应方面最不确定。DSSAT-Nwheat 和 APSIM-Wheat 分别对年份和气候条件的温度变化最敏感和最不敏感。