京津冀地区梨始花期模拟及花期冻害特征分析

SIMULATION OF FIRST FLOWERING DATE FOR PEAR AND ANALYSIS ON THE CHARACTERISTICS OF FROZEN DAMAGE DURING FLOWERING IN JING-JIN-JI REGION

关键词:  春暖模型  始花期  梨  花期冻害  时空变化

Key words:  spring warming model  first flowering date  pear  frozen damage  spatiotemporal variations

摘要:

目的 建立京津冀地区梨始花期模拟模型，对梨树花期内冻害发生特征进行分析，为当地梨的生产管理和冻害风险防范提供支撑。方法 文章基于春暖模型构建京津冀地区梨始花期模拟模型，结合1980—2020年该地区171个气象站逐日气温数据，重构各站点逐年梨始花期，研究梨树花期冻害发生特征。结果 （1）构建的梨始花期模拟模型能较好地模拟各物候观测站点的梨始花期年际变化，模型内部检验和交叉检验的均方根误差的平均值分别为2.10 d和2.85 d，决定系数的平均值分别为0.87和0.75，该模型可推广到研究区其他站点；（2）研究区梨始花期日序自南向北逐渐推迟，各站点多年平均始花期在4月2日至5月19日；1980—2020年梨始花期呈现出显著提前的趋势，各站点提前趋势在0.4~5.3d/10年；（3）研究区梨树花期内轻、中、重度冻害频次均呈现出北多南少的空间分布，且41年间大多站点表现为增多的趋势。结论 全球变暖背景下，京津冀地区梨树始花期有所提前，花期内冻害增多，仍需对梨树花期冻害加强防范。研究结果可以指导当地梨树种植和提供防灾减灾政策支撑。

Abstract:

This study aims to analyze the characteristics of frozen damage events during pear flowering period by establishing a simulation model of the first flowering period of pears in Jing-Jin-Ji region, so as to provide support for local pear production management and risk prevention of frozen damage. The method used in this study was based on the spring warming model, the simulation model of pear first flowering period in Jing-Jin-Ji region was established. Combined with the daily temperature data of 171 meteorological stations in the region from 1980 to 2020, the annual pear first flowering period was reconstructed at each station, and the characteristics of frozen damage during flowering are analyzed. The results were listed as follows. (1) The established simulation model of pear first flowering period could accurately simulate the interannual change of pear first flowering period at each phenological observation station. The mean root mean square errors (RMSE) of internal test and cross test of the model was 2.10 day and 2.85 day respectively, and the means values of the coefficient of determinations were 0.87 and 0.75 respectively. The model could be extended to other stations in the study area. (2) Affected by the geographical location and altitude of Jing-Jin-Ji region, the pear flowering period in this region was gradually postponed from south to north, and the average annual first flowering period of each site was from April 2 to May 19; From 1980 to 2020, the first flowering period of pear presented a significant advance trend, with an advance trend of each station was 0.4~5.3day/10a. (3) The frequency of light, medium and severe frost damage in the pear flowering period in the study area showed a spatial distribution of more in the north and less in the south, and showed an increasing trend in 41 years, of which the increasing trend of light frost damage was the most obvious. This was mainly due to the warming climate, and the early flowering period of all stations in Jing-Jin-Ji region was in advance. In a word, under the background of global warming, the first flowering period of pears in Jing-Jin-Ji region is advanced, and the frost damage during the flowering period is increased. It is still necessary to strengthen the prevention of the frost damage during the flowering period of pears. The results can guide local pear planting and provide policy support for disaster prevention and reduction.