北京西山侧柏林冠层不同高度处叶片水分利用效率  

Foliar water use efficiency of Platycladus orientalis of different canopy heights in Beijing western mountains area,China

作　　者：张永娥[1] 余新晓[1] 陈丽华[1] 贾国栋[1] 张祯尧 孙立博[1] 张杰铭[1] 侯贵荣 

机构地区：[1]北京林业大学,水土保持与荒漠化防治教育部重点实验室,北京100083

出　　处：《应用生态学报》2017年第7期2143-2148,共6页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41401013,41430747)资助~~

摘　　要：以北京西山广泛分布的侧柏林为研究对象,综合考虑冠层不同高度处气象因子、大气CO_2浓度以及大气CO_2中碳同位素组成的差异,对其冠层不同高度处叶片的瞬时水分利用效率和短期水分利用效率分别进行了测定,以期为区域森林生态系统固碳与耗水研究提供理论依据,为区域森林生态系统经营与维护提供技术支撑.结果表明:侧柏林冠层不同高度处叶片的瞬时水分利用效率随冠层高度的变化规律表现为上层>中层>下层,多种气象因子协同影响气孔运动,使瞬时水分利用效率受气孔限制;侧柏林冠层不同高度处的环境因子、大气CO_2浓度以及大气CO_2的δ^(13)C均存在一定差异,导致了林冠各层叶片的短期水分利用效率的变化.林冠上层叶片通过提高水分利用效率适应环境.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 ob- tained on carbon isotope model） by carefully considering the discrepancies of meteorological factors and atmosphere CO2 concentration and δ13C among different canopy heights, hoping to provide theo- retical 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 or- der 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 CO2 concentration and δ13C. Platycladus orientalis leaves in upper canopy adapted to ambient condition by improving water use efficiency.

关 键 词：侧柏林 冠层高度 瞬时水分利用效率 短期水分利用效率 

分 类 号：S791.38[农业科学—林木遗传育种]