全球气候变暖对中国种植制度的可能影响Ⅹ.气候变化对东北三省春玉米气候适宜性的影响

The Possible Effects of Global Warming on Cropping Systems in China Ⅹ. The Possible Impacts of Climate Change on Climatic Suitability of Spring Maize in the Three Provinces of Northeast China

【目的】研究气候变化背景下中国东北三省春玉米气候适宜性的变化特征,为东北地区春玉米种植的合理布局提供科学依据。【方法】本文以1981年为时间节点,把1961—2010年分为两个时间段,基于东北三省74个气象站点1961—2010年的观测资料,根据农业气象学指标,在分析1981—2010年较1961—1980年东北三省春玉米可能种植北界变化的基础上,利用APSIM-Maize模型模拟春玉米可能种植区域内各气象站点逐年的雨养产量,结合统计学方法,分析春玉米雨养产量高产性和稳产性的变化特征,并综合得到气候变化背景下中国东北三省春玉米的气候适宜区分布的变化特征。【结果】(1)与1961—1980年相比,1981—2010年春玉米的可能种植北界向北移动了158.3—285.8 km,春玉米可能种植面积增加了3.87×104 km2,占东北三省土地面积的4.91%。(2)1981—2010年,东北三省春玉米雨养产量的最高产区、高产区和次高产区面积占可能种植面积比例由81.14%增加为86.66%,其中最高产区和高产区面积比例由36.61%减少为34.82%,而次高产区则由44.53%增加到51.85%,低产区面积占研究区域面积的比例由18.86%减少为13.34%。研究区域内雨养产量的单产减少40 kg·hm-2,但由于春玉米可能种植区域总面积的扩大,特别是高产区和次高产区面积的增加,研究区域内雨养产量的总产增加了7.0%。(3)东北三省春玉米雨养产量的最稳产区、稳产区和次稳产区面积占可能种植面积的比例由80.20%增加为89.28%,且最稳产区和稳产区面积比例由40.97%增加为49.97%,而低稳产区面积占研究区域面积的比例由19.80%减少为10.72%。(4)东北三省春玉米气候适宜区和次适宜区面积占可能种植面积的比例由61.09%增加为83.00%,但最适宜区面积比例由18.83%减少为6.67%,可种植区面积占研究区域面积的比例由20.08%减少为10.33%。研究区域内春玉米可稳定获得的雨养产量的单产总体下降了171kg·hm-2,但由于春玉米可能种植区域总面积的增加,特别是适宜区和次适宜区面积的增加,研究区域内可稳定获得的雨养产量的总产增加了2.6%。【结论】全球气候变暖背景下,东北三省春玉米种植北界明显向北向西移动,春玉米的可能种植面积增加;在春玉米可能种植区域内,如果不考虑品种和栽培管理措施的适应,雨养产量的最高产区面积所占比例缩小,春玉米雨养产量的单产下降,但由于可能种植面积的增加,东北三省春玉米雨养产量的总产增加;春玉米雨养产量的稳定性增加,其中最稳产区和稳产区面积占研究区域面积的比例增加;在春玉米可能种植的区域内,春玉米的气候最适宜区面积减少明显,研究区域内春玉米可稳定获得的雨养产量的单产下降,但由于春玉米可能种植面积的增加,特别是适宜区和次适宜区面积的增加,可稳定获得的雨养产量的总产增加。

【Objective】The variabilities of distribution patterns of spring maize climatic suitability in the three provinces of Northeast China under climate change were studied, and the results will provide a scientific basis for spring maize cropping distribution in the region. 【Method】In this research, the year 1981 was taken as a time node and divided the period 1961-2010 into two sub-periods. The historical climate data from 74 meteorological stations in these three provinces from 1961 to 2010 were used. According to the agro-meteorological indices, the possible northern limit changes of spring maize in Northeast China were analyzed. The rain-fed yields in each station in the potential cropping region of spring maize were assessed by APSIM-Maize model year by year. On the basis of statistical methods, the variabilities of the rain-fed yield level and stablity zones were investigated. In summary, the variability of distribution patterns of spring maize climatic suitability were studied. 【Result】In the period from 1981 to 2010, the possible northern limit of spring maize moved with a northwestward shift of 158.3-285.8 km, and the possible planting area increased by 3.87×104 km2（4.91% of the whole land area in Northeast China） than during the period from 1961 to 1980. During the period 1981-2010, the percentage of the very high, high and moderately high rain-fed yield zones of spring maize in the possible planting area increased from 81.14% to 86.66%, but the percentage of the very high, high zones decreased from 36.61% to 34.82% and the moderately high zone increased from 44.53% to 51.85%. Meanwhile, the percentage of the marginally high zone decreased from 18.86% to 13.34%. Generally, the rain-fed yield per unit area reduced by 40 kg·hm-2 in the research area. However, the total rain-fed yield increased by 7.0% with possible planting area increase, especially the high and moderately high rain-fed yield zones. The percentage of the very stable, stable and moderately stable rain-fed yield zones of spring maize in the possible planting area increased from 80.20% to 89.28%. Meanwhile, the percentage of the very stable and stable rain-fed yield zones increased from 40.97% to 49.97%, but the percentage of the marginally stable rain-fed yield zone decreased from 19.80% to 10.72%. The percentage of the suitability and moderately suitable climatic zones increased from 61.09% to 83.00%, but the percentage of the very suitable climatic zone decreased from 18.83% to 6.67%. Meanwhile, the percentage of marginally suitability zone decreased from 20.08% to 10.33%. The rain-fed yield per unit area obtained stably reduced by 171 kg·hm-2 in the research region. However, the total rain-fed yield obtained stably increased by 2.6% with possible planting area increase, especially the suitable and moderately suitable climatic zones. 【Conclusion】Under the background of climate change, the possible northern limit of spring maize moved northwestward with an increasing possible planting area in Northeast China. If there were no changes of varieties, cultivation and management, the percentage of the very high rain-fed yield zones in the possible planting area decreased and the yield per unit area reduced. However, the total rain-fed yield increased with the possible planting area increase. The stability of rain-fed yield increased with a greater percentage of the very stable and stable rain-fed yield zones in the possible planting area increased. In the potential cropping area of spring maize in Northeast China, the percentage of the climatic suitability and moderately suitability zones increased, but the percentage of the very suitable climatic zone decreased. The rain-fed yield per unit area obtained stably reduced. However, the total rain-fed yield obtained stably increased with the possible planting area increase in the research region, especially the suitable and moderately suitable climatic zones.