Prediction of the potential distribution and analysis of the freezing injury risk of winter wheat on the Loess Plateau under climate change

Determining the suitable areas for winter wheat under climate change and assessing the risk of freezing injury are crucial for the cultivation of winter wheat. We used an optimized Maximum Entropy (MaxEnt) Model to predict the potential distribution of winter wheat in the current period (1970-2020) and the future period (2021-2100) under four shared socioeconomic pathway scenarios (SSPs). We applied statistical downscaling methods to downscale future climate data, established a scientific and practical freezing injury index (FII) by considering the growth period of winter wheat, and analyzed the characteristics of abrupt changes in winter wheat freezing injury by using the Mann-Kendall (M-K) test. The results showed that the prediction accuracy AUC value of the MaxEnt Model reached 0.976. The minimum temperature in the coldest month, precipitation in the wettest season and annual precipitation were the main factors affecting the spatial distribution of winter wheat. The total suitable area of winter wheat was approximately 4.40x107 7 ha in the current period. In the 2070s, the moderately suitable areas had the greatest increase by 9.02x105 5 ha under SSP245 and the least increase by 6.53x105 5 ha under SSP370. The centroid coordinates of the total suitable areas tended to move northward. The potential risks of freezing injury in the high-latitude and-altitude areas of the Loess Plateau, China increased significantly. The northern areas of Xinzhou in Shanxi Province, China suffered the most serious freezing injury, and the southern areas of the Loess Plateau suffered the least. Environmental factors such as temperature, precipitation and geographical location had important impacts on the suitable area distribution and freezing injury risk of winter wheat. In the future, greater attention should be paid to the northward boundaries of both the winter wheat planting areas and the areas of freezing injury risk to provide the early warning of freezing injury and implement corresponding management strategies.