Effects of elevated CO₂ concentration on water use efficiency of Tamarix ramosissima in an extremely arid region

详细信息    查看全文

• 作者：Zongqiang Chang ; Yali Ma ; Chenglin Zhou
• 关键词：Tamarix ramosissima leaves ; Transpiration ; Water use efficiency ; Concentration of CO2
• 刊名：Environmental Earth Sciences
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：75
• 期：21
• 全文大小：416 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：None Assigned
• 出版者：Springer Berlin Heidelberg
• ISSN：1866-6299
• 卷排序：75

文摘

The variation of net photosynthetic rate (P_n), transpiration rate (T_r), and intercellular CO₂ concentration (Ci) with changes in light intensity of Tamarix ramosissima leaves was studied during the growing seasons of 2012 and 2013 in the extremely arid region of Ejina Oasis, using the LI-6400 portable photosynthesis measurement system. Results indicate that Ci decreased and P_n and T_r increased with light intensity. After reaching the light saturation point, P_n decreased gradually with the enhanced greater light intensity. The apparent maximum photosynthetic rate increased with CO₂ concentration, from 17.69 to 27.05 µmol/(m2 s); apparent quantum efficiency also increased, as did the light saturation point of T. ramosissima leaves. Water use efficiency (WUE) increased initially but gradually decreased after maximizing with the enhanced light intensity. T_r and Ci increased with elevated CO₂ concentration. P_n and WUE increased with CO₂ concentration when that concentration was 200–600 µmol/mol. When that concentration increased to 1000 µmol/mol, WUE increased initially but eventually decreased.