本文利用IPCC AR5提供的全球气候模式模拟数据和全国农业气象站点数据,建立生育期与气象要素的多元回归模型,模拟基准期全国春小麦播种和收获日期的分布,研究RCP4.5情景下气候变化对中国春小麦生育期的影响;根据春小麦可能种植和适宜种植限制条件,划定春小麦基准期可能种植界线和适宜气候生态区域,考虑气候变化对春小麦生育期的影响,探讨RCP4.5情景下气候变化对中国春小麦可能种植界线和适宜气候生态区域分布的影响。结果表明:春小麦可能种植界线主要分布在山东南部-江苏北部-安徽北部-河南中部-湖北北部-四川东南部-云南北端一线,在RCP4.5情景下,中国春小麦的可能种植南界不断向北移动,春小麦可能种植面积呈减小趋势;基准期中国春小麦播种和收获日期在新疆南部-甘肃一线比较早,向该线两侧播种和收获日期均呈现推迟的现象;RCP4.5情景下,春小麦可能种植区域内播种日期普遍呈推迟现象,收获日期提早现象明显,因此,受气候变化的影响生育期会缩短;春小麦最适宜种植区域主要分布在东北三省,受气候变化影响,春小麦最适宜种植面积在不断增加,并且在内蒙古自治区增加最多;由于冬小麦可能种植界线的西扩和新疆地区冬小麦可能种植区域扩张,导致春小麦次适宜种植区和不适宜种植面积进一步减少。
This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations and meteorological simulations by GCMs, to simulate the possible planting boundaries and suitable planting re- gions of spring wheat under RCP4.5 scenario for the base period 2040s and 2070s. We find that the south bound- ary of possible planting region for spring wheat spreads along the belt: south Shandong-north Jiangsu-north Anhui-central Henan-north Hubei-southeast Sichuan-north Yunnan provinces, and will likely move northward under RCP4.5 scenario in 2040s and 2070s, resulting in the decrease of possible planting area in China. Moreover, the sowing and harvest date of spring wheat in the base period shows a gradually delayed phenomenon from the belt: south Xinjiang - Gansu, to the Tibet Plateau. As a result, the growth period of spring wheat in China will shorten because of the impacts of climate change. These results imply that a variety of adaptations measures should be set up in response to changing climatic conditions, including developing the planting base for spring wheat, restricting the planting area of spring wheat in sub-suitable areas at risk while expanding the planting area of optimal crops.