中文摘要：

利用敦煌绿洲气象站1955年-2010年日平均气温资料,采用气候倾向率、Mann-Kendall检验、相关分析及Morlet小波功率谱等方法分析了研究区胡杨生长季对全球气候变化的响应。结果表明：近56a来,研究区胡杨年生长季有开始日提前,终止日推后,年生长季天数延长的趋势;展叶始日有提前趋势,叶黄初日有推后趋势。胡杨生长季开始日、展叶始日分别与3月和4月平均气温呈负相关关系,胡杨生长季终止日、生长期天数及叶黄初日分别与10月、3月-11月及8月-9月平均气温呈正相关关系。胡杨生长季开始日、终止日、生长季天数、展叶期及叶黄初日均具有多个突变,存在3.77~8.33a的短尺度周期,这反映出研究区胡杨生长季对气候变化响应十分敏感。

英文摘要：

Dunhuang Oasis is situated at the arid and semi-arid region of northwest China. It is one of the main distribution regions of Populus euphratica, and also a sensitive region to reflect the climate change as well as an ideal place to study the climate change of arid and semi-arid region and vegetation response. The research of the vegetation’s response to climate change would be of great theoretical and practical significances for scientifically knowing the climate change and the adaptability of vegetation and formulating the response measures. Based on the daily average temperature data between 1955 and 2010 from Dunhuang Oasis weather station,this paper has analyzed the beginning date and ending date of Populus euphratica’s annual growth season, the beginning date of yellow leaves and the response of Populus euphratica to the global climate change with the methods of climate trending rate, Mann-Kendall abrupt change test, correlation analysis and the Morlet wavelet power spectrum. The results show that： 1） In the past 56 years, the beginning date of the annual growing season of Populus euphratica is becoming earlier but the ending date is becoming later; the beginning date of yellow leaves has clear delaying trend;2） The beginning dates of the annual growing season and leaf unfolding of Populus euphratica are negatively correlated with the average temperature of March and April respectively; the ending date and the annual growth period of Populus euphratica and the beginning date of yellow leaves are positivey correlated with the average temperature of October, March to November and August to September respectively; 3） The beginning date, ending date of Populus euphratica’s annual growth season, the annual growth period, the date of leaf unfolding and the beginning date of yellow leaves all have many abrupt changes. 4） There is a short scale period of 3.77 years to 8.33 years, which reflects the sensitive response of Populus euphratica’s annual growing season to the climate change in Dunhuang O