中文摘要：

林木耗水特性是森林生态学领域主要的研究内容之一。本项研究是利用Li-6400光合测定仪测定不同年龄（Ⅰ度竹、Ⅱ度竹、Ⅲ度竹）的毛竹在其快速生长期（3-5月）的净光合速率（Pn）、蒸腾速率（Tr）及其影响因子（光合有效辐射、大气温度、大气相对湿度、大气CO2浓度、胞间CO2、气孔导度）,对其水分利用动态及其相关影响因子进行了研究。结果表明,（1）毛竹水分利用效率（WUE）在快速生长中期最高,前期其次,后期最小;Tr在快速生长中期最小,前期其次,后期最大。（2）在相同生长期内,WUEⅡ度竹最大,Ⅰ度竹其次,Ⅲ度竹最差;而Tr随着竹龄增加逐渐减小。（3）水分利用效率影响因子影响程度由大到小为胞间CO2浓度、光强、大气湿度、气孔导度、大气温度、大气CO2浓度;蒸腾速率影响因子影响程度由大到小为气孔导度、光强、大气CO2浓度、胞间CO2浓度、大气温度、相对湿度。研究结果将对毛竹的固碳机制和制定科学合理的管理措施提供理论依据。

英文摘要：

The characteristics of forest water consumption is one of the main research areas of forest ecology. This article utilizes the LI-6400XT Portable Photosynthesis System to measure net photosynthetic rate （Pn） transpiration rate （Tr） and impact factor （photosynthetically active radiation, air temperature, air humidity, atmospheric CO2 concentration, intercellular CO2, and stomatal conductance） of bamboo of different ages in the rapid growth period （I degree, Ⅱ degree, III degree） and their impact on water use dynamics. The results showed that, （1） Phyl- lostachys edulis water use efficiency is highest during the mid （Ⅱ） rapid growth period, followed by the early （Ⅰ） and late （Ⅱ） rapid growth periods. In contrast, the transpiration rate was lowest in the mid （Ⅱ） rapid growth peri- od, higher in the early （Ⅰ） growth period, and highest in the late （Ⅲ） growth period. （2） In the same growth period degree, WUE was highest in the mid （Ⅱ） growth period, followed by the early （Ⅰ） growth period, with the lowest concentration in the late（Ⅲ） growth period. （3） Factors influencing water efficiency are, in order of im- portance： intercellular CO2 concentration, light intensity, atmospheric humidity, stomatal conductance, air temper- ature, and atmospheric CO2 concentration. Factors influencing the transpiration rate arc, in order of importance：stomata conductance, ture, and relative humidity. questration mechanism and intensity, atmospheric CO2 concentration, CO2 The results of this paper provide a theoretical for scientific management of bamboo. concentration intercellular, air tempera- basis for studying the bamboo carbon se-