Water use efficiency of plants in arid regions plays a key role in affecting the distribution and water use of plants. We analyzed the responses of water use efficiency of Populus euphratica and Tamarix sp. to different groundwater depths by measuring foliar δ13C of the two dominant species in a desert hinterland. The results showed that as the groundwater depth increased from 2.1 m to 4.3 m, foliar δ13C of Tamarix sp. increased slightly and remained relatively stable. Tamarix sp. had a more stable water use efficiency to adapt to the arid environment. Foliar δ13C of P. euphratica first slightly decreased and then increased. P. euphratica improved its water use efficiency to adapt to drought stress. At the same groundwater depth, foliar δ13C of Tamarix sp. was higher than that of P. euphratica, indicating that water use efficiency of Tamarix sp. was higher than that of P. euphratica.
干旱区植物的水分利用效率对植物的分布及水分利用状况具有重要意义。基于不同地下水埋深条件下沙漠腹地绿洲优势种胡杨和柽柳叶片δ13C值,分析了胡杨和柽柳的水分利用效率对不同地下水埋深的响应。结果表明: 随着地下水埋深由2.1 m增加到4.3 m,柽柳叶片的δ13C值先略有增加后处于较为稳定状态,柽柳采取较为稳定的水分利用效率适应干旱环境;胡杨叶片的δ13C值呈现先略有减小后增加的趋势,胡杨通过提高水分利用效率的策略适应干旱胁迫。同一地下水埋深条件下柽柳叶片的δ13C值高于胡杨叶片,表明柽柳的水分利用效率高于胡杨。.
Keywords: groundwater depth; hinterland of the desert; water use efficiency; δ 13 C.