摘要
通过构建三维树冠净光合速率(Pn)和蒸腾速率(Tr)的耦合模型,可模拟出树冠内叶片瞬时水分利用效率(WUEI)的三维分布。根据2011—2012年27年生开心形苹果树(Malus domestica)试验数据拟合模型参数,进而确定树冠内三维Pn和Tr分布。数值模拟结果显示,WUEI随CO2浓度和湿度的增加而迅速增加,随温度和叶水势的增大而减少;当光合有效辐射低于光饱和点时WUEI随PAR的增加而增加,超过光饱和点后WUEI变化不显著。在一天当中苹果冠层WUEI整体呈双峰曲线,多云时WUEI最高,晴天的WUEI比阴天高42%,约为2.98 mmol/mol。结果表明,该耦合模型能模拟出不同小气候条件和叶片水势下苹果三维树冠WUEI的维分布和动态变化。
A coupled model of photosynthetic rate （Pn） and transpiration rate （Tr） was developed to simulate the three-dimensional distribution of leaf instantaneous water use efficiency （WUEI） in apple canopy. For convenience, WUEI was expressed as the ratio of net Pn to Tr. The experiment was conducted in a ＇ Fuji＇ apple （Malus domestica ＇Fuji＇） orchard during the 2011-2012 growing seasons. The simulation was shown that WUEI increased rapidly with increasing CO2 concentration and relative humidity （RH）; but decreased with increasing temperature and leaf water potential （~）. The diurnal course of WUEI in the canopy showed a double-peak curve on clear day. The average WUEI on clear days was 2.98 mmol/mol which was about 42% higher than that on cloudy days. The study indicated that the sensitivity of WUEI to microclimatic factors and could be systemically assessed by the coupled model.
出处
《中国农学通报》
CSCD
2014年第22期135-139,共5页
Chinese Agricultural Science Bulletin
基金
北京市职业院校教师素质提高工程.专业带头人培养和北京农业职业学院中青年骨干教师培养和院级项目(XY-YF-13-02)
关键词
苹果
水分利用效率
三维树冠
模拟
光合作用
蒸腾作用
apple
water use efficiency
3-dimensional canopy
simulation
photosynthesis
transpiration
