塔里木河下游胡杨气体交换对CO_2加富和地下水埋深的响应  

Responds of CO_2 Enrichment and Groundwater Depth on Gas Exchange of Populus euphratica at the Lower Reaches of TarimRiver

作　　者：陈亚鹏[1,2] 陈亚宁[1,2] 李卫红[1,2] 徐长春[3] 

机构地区：[1]中国科学院绿洲生态与荒漠环境重点实验室,乌鲁木齐830011 [2]中国科学院新疆生态与地理研究所,乌鲁木齐830011 [3]新疆大学资源与环境科学学院,乌鲁木齐830046

出　　处：《水土保持学报》2008年第5期217-220,224,共5页Journal of Soil and Water Conservation

基　　金：中国科学院西部行动计划项目(KZCX22XB2203);国家自然科学基金项目(90502004;30500081);国家"十一五"支撑课题(2006BAC01A03)

摘　　要：为了探讨CO2浓度增加对干旱荒漠区胡杨气体交换的影响,在塔里木河下游4个不同地下水埋深环境测定胡杨在CO2浓度分别为360,720μmol/mol条件下的光合速率、气孔导度、水分利用效率。结果表明,在地下水埋深4.12 m和4.74 m时,当CO2浓度由360μmol/mol增加到720μmol/mol时,胡杨的气孔导度略有减小;而在地下水埋深5.54 m和7.74 m环境下,CO2浓度的增加明显减小了胡杨的气孔导度。在CO2浓度为360μmol/mol时,胡杨的光合速率随着地下水埋深的增加而减少,然而当CO2浓度增加到720μmol/mol时,胡杨的光合速率不但没有因为地下水埋深的增加而减少,反而却因此而增加。当地下水埋深在4.12 m时,CO2浓度的增加对胡杨的水分利用效率没有产生明显的影响,但是随着地下水埋深近一步增加到4.74 m,5.54 m和7.74m时,胡杨的水分利用效率因CO2浓度的倍增分别增加了69%,18%和66%。地下水埋深最终控制着干旱荒漠区胡杨气体交换对CO2浓度升高的响应。In order to understand the effects of CO2 enrichment on gas exchange of Populus euphratica, changes in stomatal conductance （gs）, photosynthetic rates （PN） and water use efficiency （WUE） of P..euphratica grown with different groundwater depths （GDs） were measured under two CO2 concentration conditions. The gs of P. euphratica with GDs at 4.12 m and 4.74 m both had a little but not significant decrease resulting fromCO2 enrichment. However, at GDs 5.54 mand 7. 74 m, the trees showed a significant difference between gs measured at 360,720 μmol/mol CO2. When measured at 360 μmol/mol, the PN decreased with increasing GD, while at 720/μmol/mol CO2, PN did not decrease but increase with increasing GD. The CO2 enrichment did not affect WUE significantly, while measured with GD at 4.12 m. However, when GD increased to 4.74 m, 5.54 mand 7.74 m, the WUE increased by 69%, 18% and 66%, respectively. The results obtained showed that groundwater depth determines the response of gas exchange to CO2 enrichment for P. euphratica in arid desert area.

关 键 词：塔里木河 气体交换 胡杨 CO2加富 地下水埋深 

分 类 号：Q945.17[生物学—植物学]