黑河下游绿洲胡杨物候期对1960～2010年气温变暖的响应

Respond of Populus euphratica Oliv.Phenology to Climate Warming in the Oasis of Lower Reaches of Heihe River from 1960 to 2010

基于黑河下游绿洲胡杨林分布区气象站1960～2010年的气温数据,利用气候倾向率、Mann-Kendall检验及相关分析等方法,研究了近51年来胡杨年生长期物候特征及其对气候变化的响应特征。结果表明:(1)黑河下游绿洲气温有明显的增暖趋势,且1960～2010年研究区内鼎新和额济纳旗绿洲气温分别增高了1.6℃和2.4℃。(2)黑河下游绿洲胡杨年生长期开始日有明显提早趋势,其中,鼎新绿洲和额济纳旗绿洲胡杨年生长期开始日的变化倾向率分别为-1.46d/10a(α=0.01),-1.54d/10a(α=0.02),51年两绿洲分别提早了7d和8d;胡杨年生长期终止日呈明显推迟趋势,51年分别推迟了5d、9d,并以额济纳旗绿洲推迟更显著,且以2000s变化最显著;胡杨生长期天数呈明显延长趋势,而且额济纳旗绿洲比鼎新绿洲的年生长期变化倾向率多延长了0.9d/10a、平均年生长期缩短了1d;胡杨叶黄开始日呈微推迟趋势,在一定的程度上响应了气候季节变化的特征,并与夏秋季气温增温变化不显著的结论相吻合。(3)上述胡杨主要物候期的突变显著不同,且以生长期终止日响应最明显,并以纬度偏北的额济纳旗绿洲胡杨响应更敏感。

Based on the daily average temperature,maximum and minimum temperature data of 2 weather stations of Dingxin,Ejina Banner in the Heihe River’s downstream in 1960~2010,using the methods of climate trending rate and Mann-Kendall abrupt change test method,the characteristics and respond of Populus euphratica’s phenology to climate change was analyzed,including beginning dates,ending dates of annual growth period,the annual growth period of P.euphratica and the P.euphratica’s beginning dates of yellow leaf stage.The results showed that：（1）The mean annual temperatures in the oasis of lower reaches Heihe River was significantly warming,and the air temperature in the study area which was the oasis of Dingxin and Ejina Banner increased respectively 1.6℃ and 2.4℃ from 1960 to 2010.（2）The change trend of P.euphratica’s characteristics was different in recent 51 years.The beginning dates of annual growth of P.euphratica in the lower reaches Heihe River was becoming earlier.The beginning dates of annual growth of P.euphratica in the oasis of Dingxin and Ejina Banner were -1.46 d/10a （α=0.01），-1.54 d/10a （α=0.02）,and they were respectively earlier 7 days and 8 days in recent 51 years.The ending dates was becoming later,they were respectively later 5 days and 9 days in recent 51 years,and it was more appreciable in the oasis of Ejina,it was the most significant in 2000s among the change of decades;The growth period of P.euphratica was prolonged,and the trend of P.euphratica’s annual growth in the oasis of Ejina was more extended 0.9 d/10a than Dingxin,and the average annual length growth was shorten 1 day;the P.euphratica’s beginning dates of yellow leaf stage was becoming slightly later,but it responsed the seasonal change of the climate characteristic in a certain extent,and it was coincided that conclusions which was the temperature changes with temperature fall were not significant.（3）There was significantly different in the abrupt change about P.euphratica phenology,and it was more sensitive in the ending dates.Therefore,it was an obvious response to the climatic change of the P.euphratica in the study area,especially there was more sensitive in Ejina Banner.