Impacts of climate change on agrometeorological indices at winter wheat overwintering stage in northern China during 2021–2050. (17th August 2018) - Hao, Zhixin
Abstract : Climate change has a significant impact on agrometeorological conditions. We analysed the winter wheat overwintering indices for the northern winter wheat production areas of China (NWPA), which include the percentage of extreme low‐temperature (daily minimum temperature ≤−22 °C) years, the first day of the overwintering period (FDO), sowing date (SD) and precipitation before winter (PBW). Then, we compared the differences of the four indices between the forecast period 2021–2050 and the baseline period 1961–1990 under the RCP4.5 scenario, which were based on the 0.5° × 0.5° grid daily meteorological data output provided by the Inter‐Sectoral Impact Model Intercomparison Project. The results showed that the occurrence of extreme cold winters decreases the NWPA, which will result in the northern boundary of winter wheat moving north by 1–2 latitudes and in an increase in the potentially safe overwintering areas by 8.5%. The FDO will be delayed in 2021–2050 by an average of 7.7 days. Climate warming will change the meteorological conditions for winter wheat overwintering in the Huang‐Huai winter wheat area, especially near the southern boundary of the winter wheat planting area, and the areas and years with no obvious overwintering periods will experience an increase by 50% and 56%, respectively. The SD will be postponed by 8.6–9.0 days. The PBW will decrease as the accumulated temperature increases, especially in the Huang‐Huai winter wheat area. In the future, the possible northern boundary for winter wheat planting may move northward, and the northernmost tip may reach 46°N. South of the Huang‐Huai region, winter wheat planting may change from a semi‐winter to a spring variety. These findings will provide a reference for generating wheat planting and management strategies in China. Abstract : Climate change has significantly influenced the winter wheat planting in northern China. In 2021–2050, climate warming would decrease the occurrence of extreme cold winters in the regions near northern planting boundary, which would result in the possible northern boundary (red and green lines) moving northward, and the northernmost tip may reach 46°N. However, south of the Huang‐Huai region (black oval areas), wheat planting may change from a semi‐winter to a spring variety due to temperature increase and precipitation reduction.