Zhang Yong E, Yu Xin Xiao, Chen Li Hua, Jia Guo Dong, Zhang Zhen Yao, Sun Li Bo, Zhang Jie Ming, Hou Gui Rong
Ministry of Education Key Laboratory of Soil & Water Conservation and Desertification Combating, Beijing Forestry University, Beijing 100083, China.
Ying Yong Sheng Tai Xue Bao. 2017 Jul 18;28(7):2143-2148. doi: 10.13287/j.1001-9332.201707.015.
In this study, we focused on Platycladus orientalis, a widely distributed tree species in Beijing western mountains area, and precisely determined its foliar water use efficiency (including instantaneous water use efficiency derived from gas exchange and short-term water use efficiency obtained on carbon isotope model) by carefully considering the discrepancies of meteorological factors and atmosphere CO concentration and δC among different canopy heights, hoping to provide theoretical basis for carbon sequestration and water loss in regional forest ecosystem, and offer technical support for regional forest management and maintenance. The results showed that the foliar instan-taneous water use efficiency tended to increase with the increasing canopy height, following the order of the upper canopy > the middle canopy > the lower canopy. A variety of meteorological factors synergistically influenced stomatal movement, and stomatal conductance would in turn have an effect on foliar instantaneous water use efficiency. Foliar short-term water use efficiency also increased with increasing canopy height, following the order of the upper canopy > the middle canopy > the lower canopy. The differences of foliar short-term water use efficiency among different heights could be explained by discrepancies of environmental drivers and atmosphere CO concentration and δC. Platycladus orientalis leaves in upper canopy adapted to ambient condition by improving water use efficiency.
