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

Understanding the suitable areas of winter wheat under climate change and assessing the risk of freezing injury are crucial for the cultivation of winter wheat. We utilized an optimized 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 abrupt change characteristics of winter wheat freezing injury by using the M-K test. The results showed that the prediction accuracy AUC value of MaxEnt model reached 0.976. The minimum temperature in the coldest month, precipitation in the wettest season and the annual precipitation were the main factors affecting the spatial distribution range of winter wheat. The total suitable areas of winter wheat was approximately 4.40×107 hm2 in current. In 2070s, the moderately suitable areas had the most increase by 9.02×105 hm2 under SSP245 and the least increase by 6.53×105 hm2 under SSP370. The centroid coordinates of the total suitable areas had a tendency to move northward. The potential risk of freezing injury in the high-latitude and high-altitude areas of the Loess Plateau increased significantly. The north areas of Xinzhou in Shanxi 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 impact on the suitable areas distribution and freezing injury risk of winter wheat. In the future, more attention should be paid to the northward boundary of winter wheat planting areas and the areas of freezing injury risk to provide the early warning of freezing injury and corresponding management strategies.