1960中国玉米生育期及各生育阶段水热条件时空变化特征Word文档格式.docx

1、结果表明, 玉米生育期Tmean、GDD的增幅分别为0.180.36（10a）1和5.7341.23（10a）1, 东北、甘新区、黄淮海平原和黄土高原等种植区增加最显著。生育期KDD的高值区主要集中在黄淮海平原和甘新地区; 除黄淮海平原西南局部区域呈不显著下降趋势外, 其他地区呈增加趋势; 且KDD的增加主要集中在苗期到花粒期。玉米生育期SD整体表现为显著下降趋势, 其中黄淮海平原和黄土高原地区玉米各生育阶段均存在显著下降趋势, 花粒期SD下降最明显。玉米生育期Pe和IR变化趋势总体上不显著但空间差异明显; 除甘新区和内蒙Pe呈现不显著增加趋势外, 全国大部分玉米种植区Pe呈不显著减少趋势。生

2、育期IR在南疆及黄淮海平原西南部呈不显著减少、东北东南部不显著增加趋势; 从各生育阶段来看, 黄淮海平原区及东北地区Pe在穗期和花粒期减少且IR相对增加, 黄淮海平原区及黄土高原西部的IR分别在播期和苗期呈现减少趋势。总体来看, 全国玉米生育期热量资源有增加趋势, 光照资源减少, 有效降水和灌溉需水量的变化趋势不明显, 但是各生育阶段及区域间水热条件变化差异明显, 如黄淮海平原和黄土高原地区苗期到花粒期KDD增加显著但SD下降, 高温胁迫可能会对玉米生长产生负影响, 同时影响对水分的消耗。因此, 未来研究更应该关注生育阶段的水热条件变化以及极端情况对玉米生长的影响。关键词: 气候变化; 玉米;

3、 水热条件; 生长度日; 高温度日; 有效降水; 灌溉需水量中图分类号: S162.3 Spatio-temporal characteristics of the hydrothermal conditions in the growth period and various gro wth stages of maize in China from 1960 to 2018*LIU Hang1,2, ZHANG Xiaolong1, WANG Yixuan1,2, GUO Ying1, LUO Jianmei3, SHEN Yanjun1*（1. Center for Agricultur

4、al Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences / Key Laboratory of Agricultural Water Resources, Chinese Academy of Sciences, Shijiazhuang 050022, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. School of Land Scienc

5、e and Space Planning, Hebei GEO University, Shijiazhuang 050031, China）Abstract: Hydrothermal conditions affect crop distribution and agricultural development. Maize is an important food crop in China and is primarily used as a fodder and energy crop. However, the growth of maize is sensitive to cli

6、mate change. Understanding the spatiotemporal characteristics of the hydrothermal conditions, especially during the growth period and at various growth stages of maize, is crucial for food security and for coping with the impacts of climate change. This study aims to explore the spatiotemporal chara

7、cteristics of the hydrothermal conditions during the maize growth period and its various growth stages in different regions of China from 1960 to 2018. The mean temperature （Tmean）, growth degree-day （GDD）, killing degree-day （KDD）, sunshine hours （SD）, effective precipitation （Pe）, and irrigation w

8、ater requirement （IR） served as the hydrothermal condition indicators, incorporating the data from 422 meteorological stations and 292 agricultural stations. The spatial and temporal variations of each indicator were explored using trend and spatial analysis methods. The results showed that Tmean an

9、d GDD generally increased in the maize growth period, 0.180.36 C（10a）1 and 5.7341.23 C（10a）1, respectively, and Tmean and GDD had risen more rapidly in Northeast China, the Gansu-Xinjiang Region, and the Huang-Huai-Hai Plain. KDD increased in the summer maize planting areas, including the Huang-Huai

10、-Hai Plain and Gansu-Xinjiang Region. KDD tended to increase nationally except in the southwestern part of the Huang-Huai-Hai Plain, where there was an insignificant decline. In the various growth stages, KDD mainly increased from the seedling stage to the flowering and kernel stages. SD in the maiz

11、e growth period showed a significant downward trend, and there was a significant downward trend in each maize growth stage in the Huang-Huai-Hai Plain and the Loess Plateau. SD declined the most in the flowering and kernel stages. Changes in Pe and IR during the maize growth period were generally no

12、n-significant, but the changes varied in different regions. Pe in different growth stages generally decreased, except in the Gansu-Xinjiang Region and Inner Mongolia, where, in past years, the Pe values increased non-significantly. IR in the maize growth period tended to decrease in southern Xinjian

13、g and the southwestern part of the Huang-Huai-Hai Plain, whereas IR increased non-significantly in parts of Northeast China. In the various growth stages, Pe decreased and IR increased at the heading and flowering stages in the Huang-Huai-Hai Plain and Northeast China, whereas IR tended to decrease

14、during the sowing and seedling stages in the Huang-Huai-Hai Plain and the western part of the Loess Plateau. Overall, there was an increasing trend of heat resources during the maize growth period in the whole country. Solar radiation tended to decrease, with no significant changes in Pe and IR. How

15、ever, there were significant differences in the water and heat conditions among growth stages and regions; KDD significantly increased from the seedling stage to flowering stage in the Huang-Huai-Hai Plain and Loess Plateau, whereas SD decreased in the same regions. Thus, high-temperature stress may

16、 negatively impact maize growth and affect water consumption in different maize growth stages. This study illustrated that changes in the hydrothermal conditions during different maize growth stages were more important than those experienced during the entire maize growth period. However, knowledge

17、of the possible spatio-temporal changes in the hydrothermal conditions in different maize growth stages is still lacking; particularly, the climate extremes during different maize growth stages in different regions of China. The results of this study highlight the impact of climate change on crop pr

18、oduction, although more detailed research is needed. Keywords: Climate change; Maize; Hydrothermal conditions; Growth degree-day; Killing degree-day; Effective precipitation; Irrigation water requirement20世纪以来, 气候变化不断加剧, 主要体现在温度持续升高, 极端天气事件数量和强度不断增加1-2。农业生产对气候条件的依赖较大, 更易受到气候变化的影响3-4。玉米（Zea mays）是中国主

19、要粮食作物中面积和产量增长最快的作物, 20042012年中国玉米种植面积增加45.2%, 但产量增加约79.7%, 玉米增产是中国粮食增产的主要贡献者5。因此, 保障玉米产量的稳定性对我国粮食安全至关重要。玉米是C4作物, 相对于其他作物对气候条件的依赖性更大, 对气候变化的敏感性也更高6-8。生育期的水热因子是影响玉米生长发育的关键。研究发现, 玉米生育期的气温超过29将会产生热胁迫, 导致光合速率下降、蒸散发增加, 进而增加干旱发生的几率9。此外, 玉米在不同生育阶段对高温的敏感度也不同, 花期高温容易导致花粉萌发数目减少2, 灌浆期高温则可能会缩短籽粒灌浆时间, 降低产量10。水分条件

20、是限制玉米生长发育的另一重要因素, 干旱是影响玉米产量减少的重要原因11。从各生育阶段来看, 生育早期的干旱会导致玉米生殖器官发育减慢12; 在生殖生长阶段, 缺水也会导致光合作用下降, 从而减少生殖器官的营养供应, 造成玉米减产13。干旱和高温的叠加效应对玉米危害更大。Matiu等14分析了干旱和高温相互作用对全球及区域尺度作物产量的影响, 结果表明, 全球玉米生育期遭遇干旱导致产量平均下降7.8%, 而干旱和高温复合作用下, 玉米产量将下降11.6%。光照同样也是影响玉米生长的关键要素, 影响着玉米干物质的积累。光合作用是玉米营养物质积累的主要来源, 约占玉米干物质积累的95%, 如抽雄吐

21、丝阶段是玉米积累干物质的关键时期, 此阶段充足的光照是保证玉米产量的关键15。中国玉米种植区域分布广泛, 经纬跨度较大, 光热资源差异明显且水资源分布不均, 不同地区的气候变化也有较大的差异。气候变化背景下, 中国玉米生育期的热量资源增加, 辐射资源减少, 降水季节变化加剧16。近年来, 许多学者就玉米生育期的水热条件进行了研究。马洁华等17对过去50年华北地区的水热资源研究发现, 华北地区热量增加, 大于10积温显著增加, 但降水量呈减少趋势, 夏秋季节减少速率在2540 mm（10a）1。杨若子等18指出东北地区玉米生育期内大于10有效积温除大兴安岭地区外, 其他地区普遍增加200400。

22、高晓容等19对东北地区不同玉米生育期的需水量进行了研究, 结果表明乳熟成熟阶段呈现出干旱化的趋势。王曼等20指出近30年来喀什地区玉米生长季的有效积温增加显著, 2000年之后热量资源增加最为明显。代立芹等21研究发现, 河北省玉米生育期内的日照时数呈现出总体减少的趋势, 日照适宜度下降; 同时, 幼苗期的温度也存在升高趋势且温度适宜度下降。尽管玉米生育期水热条件变化研究已取得一定进展, 但水热条件的变化存在区域特征, 全国尺度玉米生育期水热条件变化特征的研究还相对较少; 此外, 作物不同生育阶段对水热因子的敏感性不同, 研究不同生育阶段的水热因子变化特征也显得尤为必要。因此, 本次研究在前人

23、研究的基础上, 将玉米分为不同的发育期, 进而对各个发育期的热力因子平均温度（Tmean）、生长度日（GDD）、高温度日（KDD）、日照时数（SD）和水分因子有效降水（Pe）、灌溉需水量（IR）的时空变化特征进行探究, 以期为制定有针对性的气候变化适应措施, 提高我国玉米产量和保障产量的稳定性提供理论依据。1 数据来源及研究方法1.1 数据来源全国范围玉米种植区域分布图来自于MIRCA200022数据集, 并按照中国综合农业区划将中国地区分为九大农业种植区23（图1）。日最高温度、最低温度和平均温度、日降水量、日照时数、风速、相对湿度等气象数据来源于中国气象数据网（）, 共选取了玉米种植区内均

24、匀分布且数据完整的422个气象站点, 时间跨度为19602018年。玉米物候资料来自于中国气象数据网提供的中国农作物生长发育数据集, 其中包含292个农气站观测的玉米生长发育日期, 同时参考统计年鉴和论文资料得到24。图1 中国九大农业种植区（a）和玉米种植面积、气象和农业站点（b）分布Fig. 1 Distribution of nine agricultural planting areas （a） and maize planting areas, meteorological and agricultural observation stations （b） in China1.2 研

25、究方法1.2.1 玉米生育期划分结合中国气象局农业观测站的观测数据、统计年鉴及论文资料, 将玉米的整个生育期划分为播种期（播种出苗）、苗期（出苗拔节）、穗期（拔节抽雄）、花粒期（抽雄成熟）4个生育阶段, 并总结出全国尺度玉米各生育阶段的具体日期, 如表1所示25-27:1.2.2 玉米生育期生长度日和高温度日生长度日（growing degree days, GDD）指完成某一生育阶段所经历的有效积温, 能够很好地表征作物生育期的热量资源28-30。玉米适宜生长的温度范围在929之间29,31, GDD计算如公式（1）和公式（2）所示: （1） （2）式中: Tmin为日最低温度, Tmax为

26、日最高温度, Tlow为玉米生长适宜的最低温度阈值（9）, Thigh为玉米生长适宜的最高温度（29）。表1 中国不同农业种植区玉米生育期划分Table 1 Division of maize growth periods in different regions of China农业种植区Agricultural zone春/夏玉米Spring/summer maize播种期（月-日）Sowing period （month-day）苗期（月-日）Seedling period （month-day）穗期（月-日）Ear period （month-day）花粒期（月-日）Flowering

27、 to maturity period （month-day）东北区Northeast zone春 Spring04-2005-1005-1006-1706-1707-2507-2509-10内蒙古及长城沿线地区Inner Mongolia and areas along the Great Wall05-0505-2505-2506-2506-2507-2507-2509-23黄土高原地区Loess Plateau zone夏 Summer06-0506-2006-2007-1007-1008-1008-1009-1605-1006-2006-2007-2507-2509-24黄淮海地区Hu

28、ang-Huai-Hai zone 夏 Summer甘新区Gansu-Xinjiang zone04-2505-1305-1306-1706-1707-2007-2009-2506-1607-0507-0508-0508-0509-0509-0510-03西南区Southwest zone04-0104-1104-1105-1105-1106-1206-1208-01长江中下游流域地区Middle and Lower Reaches of the Yangtze River03-0503-1503-1505-0105-0106-0106-0107-11华南区Southern zone02-2503-0503-0504-0104-0105-0105-0106-11当温度超过玉米生育期的适宜温度, 会对玉米的生长带来不利影响。高温度日（killing degree days, KDD）是表征作物生育期的高温灾害的热量指标28,30, 计算公式为: （3）