Climate change and rising atmospheric CO2 levels are critical factors influencing agricultural productivity, particularly in Morocco, where cereal crops are essential for food security. The primary objective of this study is to evaluate the combined effects of atmospheric CO2 variations and climatic changes on cereal yields up to 2099 using the CARAIB dynamic vegetation model. This evaluation is driven by four future scenarios based on the Euro-CORDEX initiative's regional climate models under the Representative Concentration Pathway 8.5. As part of this evaluation, the study also validates the CARAIB model for Morocco’s major cereal crops: soft wheat, durum wheat, and barley, in order to ensure the model's accuracy in simulating crop responses under projected environmental conditions. The CARAIB model effectively simulated historical cereal yield trajectories across major farming regions in Morocco from 2000 to 2016, demonstrating its robust predictive capability. Our future projections suggest that elevated CO2 levels might initially sustain cereal yields at approximately 90 % of current levels until 2050. This trend indicates that the increase in atmospheric CO2 may exert a moderating influence on the negative impacts of other environmental stressors on crop yields. However, despite this initial buffering effect, the overall yield trend from the present until 2099 indicates a decrease for most combinations of crop, zone, and climate model, even with the CO2 fertilization effect, except in some cases, the model exhibits slight increases or stabilization in yields. Additionally, the CARAIB model predicts potential yield shocks of 10–35 % below current levels from the 2080 s onwards, primarily due to periodic droughts. This variation underscores the complexity of the interplay between CO2 fertilization and climatic changes, emphasizing the urgent need for Morocco to develop adaptive agricultural strategies for long-term sustainability in the face of climatic challenges.

中文翻译：

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使用 CARAIB 动态植被模型的摩洛哥大气 CO2 施肥对谷物产量的影响


气候变化和大气中二氧化碳水平上升是影响农业生产力的关键因素，尤其是在摩洛哥，那里的谷物作物对粮食安全至关重要。本研究的主要目的是使用 CARAIB 动态植被模型评估大气 CO2 变化和气候变化对截至 2099 年的谷物产量的综合影响。该评估由基于 Euro-CORDEX 倡议在代表性集中路径 8.5 下的区域气候模型下的四种未来情景驱动。作为评估的一部分，该研究还验证了摩洛哥主要谷物作物（软小麦、硬粒小麦和大麦）的 CARAIB 模型，以确保该模型在预测环境条件下模拟作物响应的准确性。CARAIB 模型有效地模拟了 2000 年至 2016 年摩洛哥主要农业地区的历史谷物产量轨迹，展示了其强大的预测能力。我们未来的预测表明，到 2050 年，二氧化碳水平升高最初可能会将谷物产量维持在当前水平的 90% 左右。这一趋势表明，大气中 CO2 的增加可能会对其他环境压力因素对作物产量的负面影响产生缓和影响。然而，尽管有这种初始缓冲效应，但从现在到 2099 年的总体产量趋势表明，即使有 CO2 施肥效应，作物、区域和气候模式的大多数组合也会下降，除非在某些情况下，该模式的产量略有增加或稳定。此外，CARAIB 模型预测，从 2080 年代开始，潜在的产量冲击将比当前水平低 10-35%，这主要是由于周期性干旱。 这种变化凸显了二氧化碳施肥与气候变化之间相互作用的复杂性，凸显了摩洛哥迫切需要制定适应性农业战略，以便在面临气候挑战时实现长期可持续性。