气候变暖对东北三省春玉米布局的可能影响及其应对策略

玉米是我国重要的粮食作物之一,东北三省春播玉米区是我国第一大玉米产区,在气候变暖背景下研究气候变化对东北春玉米生产的影响及其应对策略,对我国粮食安全具有重大意义。论文以东北三省为研究区域,利用71个气象台站1961—2010年和未来气候情景RCP 4.5下2021—2040年逐日温度数据,分析了气候变化情景下东北三省热量资源和春玉米种植熟性的时空变化特征,探索性地研究了东北春玉米应对气候变暖应采取的对策。研究结果表明：未来2个年代际,东北三省日平均气温稳定通过10 ℃初日提前、10 ℃终日和初霜日推迟,稳定通过10 ℃日数和积温呈增加趋势,其中三江平原地区变化幅度最大,10 ℃初日将提前约8 d,初霜日推迟约10 d,10 ℃日数和积温分别增加约15 d和300 ℃·d;不同熟性春玉米种植北界在未来 2个年代际的北移东扩速度较过去50 a更快,尤其是中晚熟春玉米可种植区北界到2030年代将北移至49°32′N、东扩至我国东部边境135°E;为应对气候变暖,在不改变耕作制度和更换更晚熟春玉米品种的前提下,预计到2030年代,东北的松嫩平原春玉米播种期可提前或推迟16~20 d,部分地区可超过20 d;三江平原和辽河平原区可提前或推迟8~12 d;南部沿海地区播种期变化范围较小,在8 d以内;同时,亦可通过种植区北移东扩以充分利用气候变暖带来的热量资源,预计到2030年代,东北三省晚熟、中晚熟和中熟春玉米的种植北界将在现有基础上分别北移2°13′N、1°08′N和近3°N。

The Effects of Climate Warming on Different Cultivars of Spring Maize under Climate Warming in Northeast China and the Adaptation Countermeasures

Maize is one of the main grain crops in China, and three provinces of Northeast China are the main areas of planting spring maize. The study on the effects of climate warming on spring maize and the adaptation countermeasures is important for national food security. In this paper, daily time series of air temperature during the past 50 years (1961-2010) and the next 20 years (2021-2040) under RCP 4.5 scenario at 71 stations were jointly used to study the spatio-temporal characteristics of heat resources and spring maize cultivars in Northeast China. At the same time, the adaptation countermeasures under RCP 4.5 scenario are discussed. Results show that in the next 20 years, the first date of air temperature ≥10 ℃ stably will be gradually earlier, and the end data of air temperature ≥10 ℃ stably and the first frost date will be later in Northeast China. Therefore, the durative days and accumulated air temperature ≥10 ℃ stably will increase accordingly. The maximum fluctuations of heat resources locate in Sanjiang Plain, where the first date of air temperature ≥10 ℃ stably shift 8 days earlier, and the first frost date are 10 days later. Correspondingly, the durative days and accumulated air temperature ≥10 ℃ stably increase about 15 d and 300 ℃·d, respectively. In the next two decades, the northern boundaries of different spring maize cultivars will move to north and east faster than in the past 50 years. Till 2030s, the north boundary of the mid-late spring maize will expand to 49°32′N, and the east boundary will be at 135°E based on RCP 4.5 scenario. If the planting system is the same as current in 2030s, the sowing date can be 16-20 days earlier or later in Songnen Plain, and be 8-12 days in Sanjiang Plain, and be less than 8 days earlier or later in the coastland of the south region. The alternative countermeasure is to move different spring maize cultivars northward and eastward when climate become warming. If so, the north boundaries of late maize, mid-late maize, and mid maize will move northward about 2°13′N, 1°08′N and 3°N to current boundaries in Northeast China.