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结合对塔里木河下游不同断面地下水位变化和植物生理生态特性的分析测试,研究了塔里木河下游主要建群种胡杨和柽柳在不同地下水位条件下的生理响应和适应性,探讨了塔里木河下游干旱环境下胡杨、柽柳的合理生态水位问题．研究结果表明,胡杨和柽柳叶片的可溶性糖、游离脯氨酸、内源植物激素脱落酸以及细胞分裂素浓度等与地下水位埋深有着密切的关系．随地下水位埋深加大和植物受到的生理胁迫加强,植物叶片的细胞分裂素浓度逐渐减少,而可溶性糖、游离脯氨酸和脱落酸含量增加,在距河道最远处(500m)达到最高值;比较胡杨、柽柳对不同断面地下水位变化的响应可见,在地下水位埋深较浅的亚合浦马汗断面,胡杨、柽柳的各项生理指标变化较小,而在地下水位埋深较大的依干不及麻断面,随地下水位埋深加大,可溶性糖和内源植物激素脱落酸含量呈线性关系增加,其中游离脯氨酸含量在距河道300 m处出现异常积累,反映了植物生理受到强烈胁迫;同时还发现,在一定强度的水分胁迫下,柽柳的生理过程较胡杨强烈,对地下水位埋深变化更为敏感,胡杨的抗旱性较之为强;结合样地调查结果,推测塔里木河下游胡杨、柽柳的合理生态水位埋深在4 m以内,9 m以下为胡杨和柽柳死亡的临界地下水位．
Based on the analysis of the changes of groundwater level and plant eco-physiological characteristics at different sections of the lower reaches of Tarim River, the physiological responses and adaptation of Populus euphratica and Tamarix ramosissima under different water table conditions were studied. The effects of drought Environmental Problems of Populus euphratica and Tamarix in the Environment. The results showed that soluble sugar, free proline, endogenous plant hormone abscisic acid and cytokinin concentrations in leaves of Populus euphratica and Tamarix chinensis were closely related to the depth of groundwater table. With the increase of groundwater depth and the physiological stress of plants, the concentration of cytokinin in plant leaves gradually decreased, while the content of soluble sugar, free proline and abscisic acid increased, reaching the highest value at the distance of 500 m from the river Comparing the responses of Populus euphratica and Tamarix ramosissima to the variation of groundwater level in different sections, it can be seen that the physiological indexes of Populus euphratica and Tamarix in Populus euphratica have a small change in Maha-Khan section of Aqiaon where water depth is shallow, In the dry section, with the depth of groundwater table increasing, the content of soluble sugar and endogenous phytohormones abscisic acid increased linearly, and the content of free proline accumulated abnormally at 300 m away from the river, which reflected that plant physiology was affected Under the certain intensity of water stress, the physiological process of Tamarix chinensis is stronger than that of Populus euphratica, more sensitive to the change of the depth of groundwater table, and the drought resistance of Populus euphratica is stronger than that of Populus euphratica. Based on the survey results of the sample plots, The reasonable ecological water level of Populus euphratica and Tamarix in the lower reaches of the river lies within 4 m, and below 9 m is the critical water table for the death of Populus euphratica and Tamarix.