胡杨树轮记录的乌兰布和沙漠腹地地下水位变化

利用在乌兰布和沙漠腹地的胡杨树轮样芯，建立胡杨树轮宽度年表，并对年表的统计特征及各气候要素响应情况进行了一系列分析。将标准年表（STD年表）与采样点附近吉兰泰、巴音诺尔公、惠农气象站的降水、温度等气候要素进行相关分析，发现胡杨树轮宽度变化与降水、温度等气候要素相关性不显著，表明降水、温度等气候要素均不是胡杨生长的限制条件。结合胡杨生长特性及腾格里沙漠地区气候特点，可推测当地胡杨生长主要受到地下水的影响。通过对胡杨树轮宽度年际变化的分析，得出乌兰布和沙漠腹地1828~2011年地下水位变化情况。年表序列的功率谱进行分析结果发现，序列具有较为显著的2.5a，3.6a,7.5a，50a，73a周期，且在百年时间尺度上具有下降趋势。推断未来的十年，乌兰布和沙漠腹地地下水位将进一步下降。

Groundwater level variability inferred from Tree-Rings of populu seuphratica in northeast margin of Ulan Buh Desert

On the basis of tree-ring cores collected from populu seuphratica in the hinterland of Ulan Buh Desert, Tree-ring width chronologie（STD） was developed and the features of the chronolo-gies were also analyzed. The correlation analysis between stan-dardized width chronologies and temperature and precipitation of nearby weather stations show that the correlations are not remark-able. The temperature and precipitation are not the main limiting factor to tree-ring radial growth. Considering the characteristics of populu seuphratica and regional climate in the hinterland of Ulan Buh Desert, we conclude that it＇s the groundwater level which limit the tree growth. Through the analysis of Tree-ring width chronolo-gie, the change of groundwater level from 1828 to 2011 is drew. Besides, power spectrum analyses suggested that STD chronology had significant periodicities of 2.5a,3.6a,7.5a,50a and 73a.