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借助树木年轮水文学的方法,分析不同胸径胡杨在不同地下水埋深条件下其径向生长量的变化特点和规律。研究结果表明:随着地下水埋深的增加,不同胸径胡杨径向生长量均呈现明显降低趋势,其对地下水埋深变化响应的灵敏度降低幅度呈现先增加,后减少的趋势。3个胸径等级的胡杨径向生长灵敏度最大值对应的地下水埋深为分别是3.3、7.4、7.9 m。说明,不同生长阶段的胡杨径向生长量变化对地下水埋深变化响应的敏感性存在差异。可以认为这3个地下水埋深是不同胸径等级胡杨径向生长水分胁迫的合理生态水位。
With the method of tree-ring hydrology, the characteristics and regularities of the radial growth of Populus euphratica under different groundwater depths were analyzed. The results show that with the increase of groundwater depth, the radial growth of Populus euphratica with different DBH decreases obviously, and the decrease of sensitivity to groundwater depth changes first and then decreases. The maximum depth of radial growth sensitivity of Populus euphratica at three DBH levels corresponds to groundwater depths of 3.3, 7.4 and 7.9 m respectively. This shows that there is a difference in sensitivity between the growth of Populus euphratica under different growth stages in response to groundwater depth changes. It can be considered that the three groundwater depths are reasonable ecological water levels for radial growth of Populus euphratica under different DBH classes.