近55年来民勤绿洲胡杨林物候对气候变化的响应

Response of Populus euphratica Oliv to Climate Change in Minqin Oasis from 1955 to 2009

利用民勤绿洲气象站1955—2009年日平均气温资料,采用气候倾向率、Mann-Kendall等方法,分析了胡杨年生长期开始日、终止日、生长期天数、展叶始日和叶黄始日的变化特征及其对气候的响应。结果表明:近55a来,民勤绿洲胡杨年生长期开始日有明显提早趋势,终止日有明显推后趋势,生长期天数有显著延长趋势,展叶始日有明显提早趋势,叶黄始日有显著推迟趋势。胡杨年生长期终止日、天数、叶黄始日与其对应月平均气温呈显著正相关关系,相关系数分别为0.580 5,0.610 7和0.489 9。而开始日、展叶始日与其对应月平均气温呈负相关关系,相关系数分别高达0.728 7和0.660 3。突变分析表明:年生长期开始日在1957年、2005年和2007年发生突变;年生长期终止日在1961年,1997年和1998年;生长期天数在1960年和2002年;展叶始日在1958年、1997年和2003年;叶黄始日在1962年、1987年和1988年。可见,胡杨对气候变化的响应敏感。

Based on the daily average temperature data of the weather station of Minqin Oasis during the period from 1955 to 2009,this paper analyzed the beginning dates,ending dates,length,beginning dates of leaf expansion and coloration during Populus euphratica growth period and the response to climate change with the methods of climate trending rate,Mann-Kendall abrupt change test.The results showed that：in last 55 years,the trend of the beginning dates of annual growth period of Populus euphratica was becoming earlier obviously,while the ending dates were opposite with the beginning dates,and the trend of the beginning dates and ending dates was obvious.What′s more,the beginning dates of leaf expansion were apparently earlier and the beginning dates of leaf coloration were clearly later.The relationship between average temperature of month and ending dates was positively related during Populus euphratica growth period,the same with length and beginning dates of leaf coloration,the correlation coefficient was 0.580 5,0.610 7and0.489 9,respectively.While the beginning dates and beginning dates of leaf expansion were negative correlation,the correlation coefficient was 0.728 7and 0.6 603,respectively.The abrupt change analysis results indicated that the beginning dates of the annual growth period abruptly changed in 1957,2005 and 2007,while the ending dates in 1961,1997,1998 and length of the annual growth period abruptly changed in 1960and2002.At the same time,the beginning dates of leaf expansion in 1958,1997 and 2003,the beginning dates of leaf expansion was in 1962,1987 and 1988.There was an obvious response to the climate change of the seasons,and thus the Populus euphratica was an indicator of the climate change in Minqin Oasis.