异质生境中山东银莲花光响应曲线模型的优选及光合生理特性分析

Optimization of Light-response Curves and Analysis of Photosynthetic Physiological Characteristic of Anemone shikokiana in Heterogeneous Habitats

为推断不同生境中山东银莲花不同光强下光合参数的变化规律,在相同的CO2浓度、水分、气压等条件下,设定有效光辐射强度梯度,用光合测定仪测定光合参数,并对多种光响应模型拟合光曲线进行分析。结果表明:山顶灌丛的山东银莲花根据光合参数实测值与预测值的标准误、残差平方和、判定系数大小确定了各模型的拟合效果为直角双曲线修正模型>非直角双曲线模型>指数函数模型>直角双曲线模型;针阔混交林下山东银莲花4个模型拟合效果区别不大,其中直角双曲线修正模型最佳。山顶灌丛山东银莲花光强大于1200μmol·m^-2·s^-1时,出现了光抑制,表现为气孔导度变小、蒸腾速率下降,光合速率降低,混交林下生境的则表现为一直上升的稳定趋势,充分体现该种在不同环境下都具有良好的适应性。

In order to deduce the variation of photosynthetic parameters of Anemone shikokiana under different light intensities,in this study,the effective light intensity gradient was set under the same carbon dioxide concentration,humidity and air pressure.The light and parameters were measured by photosynthetic,and the fitting light curves of various light response models were analyzed.The results showed that the modified rectangular hyperbola model was the best one among four fitting models of light-response curve to A.shilokiana in mountaintop according to standard error,residual sum of squares and decision coefficient between measured values and predicted values.There was no significant differences among 4 fitting models to A.shikokiana under mixed forest.When photosynthetically active radiation was above 1 200 μmol ·m ^-2 ·s^-1 ,photoinhibition was taken place in A.shikokiana of mountaintop,and net photosynthetic rate,stomatal conductance and transpiration rate declined.However,they always were on the rise under mixed forest.Therefore, A.shikokiana has the well adaptability to different environments.