长江中下游地区水稻孕穗开花期高温发生规律及其对产量的影响

以长江中下游平原7个省(市)的19个地区作为样点,统计分析了各样点近36年(1970—2005年)水稻始穗前15d至始穗后20d内日最高气温≥35℃的时空分布特点;并根据全球气候渐变模型GISS GCM Transient B Runs生成的研究区域2030、2050年的气候渐变情景,分析了该地区未来水稻孕穗开花期≥35℃高温逆境的时空演变趋势。结果表明:近36年来长江中下游的早稻孕穗开花期出现高温日数的上升趋势显著,未来气候情景下水稻逆境指标出现日数最多的是单季稻,其次依次为早稻、后季稻;双季稻种植区,在未来气候变化中,长江中游地区温度逆境出现日数将大于下游地区。研究区域水稻气候产量的增减与该地区水稻逆境指标的关系说明,高温导致的颖花败育是水稻减产的重要原因;未来气候变化的两种(2030、2050)情景下,长江中游地区的减产幅度大于长江下游地区,减产幅度最大的是长江中游地区的后季稻。

Occurrence patterns of high temperature at booting and flowering stages of rice in the middle and lower reaches of Yangtze River and their impacts on rice yield

Taking 19 regions of 7 provinces and municipalities in the middle and lower reaches of Yangtze River as the objects,this paper analyzed the temporal and spatial distribution patterns of their daily maximal temperature over 35 ℃ from the 15th day before rice booting to the 20th day after rice flowering in last 36 years (1970-2005).According to the climate transient scenarios of these regions in 2030 and 2050 generated by GISS GCM Transient B Runs,the temporal and spatial evolving tendency of the daily maximal temperature over 35℃ was further discussed.In last 36 years,the day number of high temperature at the booting and flowering stages of early rice in the middle and lower reaches of Yangtze River increased significantly,and under the future climate scenarios,the day number of high temperature would be the largest for single-cropping rice,followed by for early rice and late rice.For double-cropping rice production areas,the day number of high temperature in the middle reaches would be larger than that in the lower reaches of Yangtze River.The relationships between the regional quantity of rice climate yield and the stress-index occurrence pattern in the same regions suggested that the rice-spikelet abortion due to high temperature was the main cause for the decrease of rice yield.In the two climate transient scenarios in 2030 and 2050,the yield decrement in the middle reaches of Yangtze River would be larger than that in the lower reaches,and the largest yield decrement would be the late rice in the middle reaches of Yangtze River.