1961～2009年湖北省柑橘冻害等级及其特征分析

Grade and Feature Analysis on Freeze Injury of Citrus in Hubei Province from 1961 to 2009

利用湖北省70个气象站点1961～2009年冬季气温、降水资料,分析了湖北省区域柑橘(Citrus reticulata Blanco)越冬期极端低温、低温最长持续时间、降水最长持续时间和降水量的时空变化特征,并以此为基础提出柑橘综合冻害指数和冻害等级的对应关系。结果表明,自1961年以来,湖北省冬季极端最低气温以每10年0.62℃的速率升高,全省一致上升,且鄂东南高于鄂西北;柑橘越冬期间低温最长持续时间每10年下降0.8 d,20世纪80年代后减少明显,但2008年出现历史次高值,属于反常年份;柑橘越冬期降水量每10年增加4.6 mm,而降水最长持续时间变化不大。49年来湖北省柑橘的综合冻害指数呈下降趋势,每10年缩短0.36;以20世纪60年代的综合冻害指数最高,至21世纪的头9年,综合冻害指数下降至最低值。在气候变暖的背景下,柑橘发生重度冻害以上的几率明显下降,但轻度、中度冻害的几率增加。

Based on winter temperature and precipitation data collected from 70 meteorological stations in Hubei province, the temporal and spatial variation characteristics of extreme low temperature, the longest duration of low temperature, and the longest duration of precipitation and amount of precipitation in wintering period of citrus （Citrus reticulata Blanco） in Hubei province were analyzed, according to which the freeze injury index and freeze injury grade of citrus was brought forward. The results showed that since 1961, extreme low temperature in winter has been rising at the rate of 0.62 ℃/10 a; and the in- creasing trend in Hubei province was consistent, which was higher in southeast than in northwest. The longest duration of low temperature in wintering period of citrus shorteaed at the rate of 0.8 d/10a, and reduced significantly since 1980s; but there was a second highest value in 2008, which was abnormal. The amount of precipitation in wintering period of citrus increased at the rate of 4.6 mm/10 a, while the longest duration of precipitation did not changed much. In the past 49 years, the freeze injury index of citrus showed a significant downward trend in Hubei province with the rate of 0.36/10 a. The freeze injury index was the highest in 1960s and the lowest in the first 9 years of 21th century. Under the background of global warming, the occurrence of severe freeze injury decreased obviously; however, the occurrence of mild and moderate freeze injury increased.