Climate change has likely impacted crop yield potential in major rain-fed crop-growing regions. However, the impact on the spatial pattern across regions is unclear. Here, the wheat belt of Western Australia was used as a case study to investigate the effect of historical climate change on the spatial patterns of water-limited crop yield. We used 117 years (1900–2016) of observed daily climate data on ~ 5 km × ~ 5 km grids to map and quantify the spatial-temporal changes in water-limited wheat yield simulated by the APSIM model. The climate data were split into four periods based on distinct changes in rainfall (Period 1, 1900–1934; Period 2, 1935–1974; Period 3, 1975–1999; and Period 4, 2000–2016). The results showed that the observed decreases in rainfall shifted the regional wheat yield potential towards the southwest of the wheat belt by an average of 70 km between the first and last periods. Observed increases in CO 2 counteracted this by about half of this movement. Actual wheat yields achieved by farmers have not decreased, thanks to improvements in crop genetics and management, but the simulated decrease in water-limited yields has meant that actual yields in this region are not as high as they might have been. Future climate change is likely to continue to impact on water-limited crop yield and its spatial pattern in Western Australia. Cropping systems will need to continually evolve to cope with a changing climate, and every aspect of agronomy and genetics needs to be considered. Without continuing improvements, there will likely be a decrease in wheat yield across this cropping region.

中文翻译：

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历史气候变化是否影响了整个西澳大利亚缺水小麦产量的空间分布？

气候变化可能影响了主要雨养作物种植区的作物产量潜力。然而，对跨区域空间格局的影响尚不清楚。在这里，以西澳大利亚州的小麦带为例，研究历史气候变化对缺水作物产量空间格局的影响。我们使用 117 年（1900-2016 年）在 ~ 5 km × ~ 5 km 网格上观测到的每日气候数据来绘制和量化 APSIM 模型模拟的缺水小麦产量的时空变化。气候数据根据降雨量的不同变化分为四个时期（1900-1934 年期间 1；1935-1974 年期间 2；1975-1999 年期间 3 和 2000-2016 年期间 4）。结果表明，观测到的降雨量减少使区域小麦产量潜力在第一个和最后一个时期之间平均向小麦带西南方向移动了 70 公里。观察到的 CO 2 的增加抵消了这一运动的大约一半。由于作物遗传学和管理的改进，农民的实际小麦产量并未下降，但受水限制产量的模拟下降意味着该地区的实际产量并不像他们想象的那么高。未来的气候变化可能会继续影响西澳大利亚缺水作物产量及其空间格局。种植系统需要不断发展以应对不断变化的气候，并且需要考虑农学和遗传学的各个方面。没有持续改进，