2003-2019年山东省冬小麦关键物候期时空特征

农作物物候的变化会直接影响农作物的生长过程，进而影响其质量和产量。基于MODIS EVI遥感数据，提取2003-2019年山东省冬小麦种植区以及主要物候期（返青期、拔节期、抽穗期、成熟期）信息，并分析各物候期的时空变化特征。结果表明：2003-2019年山东省冬小麦返青期、拔节期、抽穗期、成熟期分别集中在一年中的第45-70天、第75-100天、第103-125天、第135-155天；4个物候期的空间分布均呈鲁南早于鲁北、内陆早于沿海的格局特征。区域尺度上，返青期、拔节期、抽穗期、成熟期年际变化率分别为1.56 d/10a、0.65 d/10a、-0.54 d/10a、2.51 d/10a，变化趋势均不显著。像元尺度上，返青期与拔节期变化以推迟趋势为主，呈显著推迟趋势的区域分别占总面积的1.65%、3.05%，这些区域主要分布于鲁东沿海地区和鲁南内陆地区；抽穗期变化以提前趋势为主，呈显著提前趋势的区域占总面积的6.56%，集中分布于菏泽东北部地区；成熟期变化以推迟趋势为主，呈显著推迟趋势的区域占总面积的10.23%，多出现在滨州、德州以及济宁等地区。研究结果可为山东省农田和冬小麦管理以及农业生态保护等提供数据支持和科学参考。

Spatio-temporal characteristics of key phenology of winter wheat in Shandong Province from 2003 to 2019

Crop phenology is a widespread natural phenomenon with annual cycle due to the influence of environmental factors including climate change, surface cover, hydrological status, soil physicochemical properties and field management. It''s well known that the phenology not only responds to climate change significantly but also plays an important role in regulating the change of ecosystem structure and functions. For example, the crop phenological changes will directly influence a variety of biophysical and physiological processes of the crops and thus influence the quality and yield of the crops. Therefore, more and more scientists in worldwide focused on the topic of crop phenology. In this study, based on the MODIS EVI multi-temporal remote sensing data, the field samples as well as the high-spatial-resolution Google Earth images, the winter wheat planting area and key phenological stages (green-up date, jointing date, heading date and maturity date) in Shandong Province from 2003 to 2019 were extracted, and the spatial and temporal characteristics of each phenological stage mentioned above were analyzed. The results showed that the green-up date, jointing date, heading date and maturity date of winter wheat in Shandong Province from 2003 to 2019 were concentrated in the 45th-70th day of year, 75th-100th day of year, 103th-125th day of year and 135th-155th day of year, respectively, and showed a spatial pattern of the south earlier than the north, as well as inland earlier than the coastal regions. At the whole regional scale, the decade trend rates of green-up date, jointing date, heading date and maturity date were 1.56 d/10a, 0.65 d/10a, -0.54 d/10a and 2.51 d/10a, respectively, and the change trend of the key phenological stages all presented an insignificant feature. At the pixel scale, the green-up date and jointing date were mainly delayed, and the areas with the significant delay tendency accounted for 1.65% and 3.05% of the total area, which were mainly distributed in the eastern coastal regions and the southern areas of Shandong Province. Nearly 6.56% of the total area showed a significant advance trend of the heading date, which was mainly located in the northeast of Heze. What''s more, the area with a significant delay trend of maturity date was accounted for 10.23% of the total area, which was generally found in Binzhou, Dezhou and Jining. It is expected that the results will provide data support and scientific reference for farmland and winter wheat management, as well as agricultural ecological protection in Shandong Province.