田间小麦叶片气孔对环境因子响应的模拟及叶片水分平衡的计算

经实测与数据分析得出田间供试小麦叶片气孔对光强、叶温、叶片水势分别作一定形式的响应,据此估算了冠层总气孔导度,进而建立了预测小麦群体蒸腾速率、冠层总气孔导度、叶温、叶片水势等的水分平衡模型。实验表明模型具有较好的预测性。供试小麦叶片一天中可溶性糖含量变化对叶片水势的影响不大。

Mathematical Simulation of Responses of Wheat Stomata to Environmental Fractors in the Field

A function describing the responses of sto- mata to environmental variables has been es- tablished and fitted with measured stomatal conductance of winter wheat and meteorological data. The fitted results show that the respon- ses of the stomata to solar radiation, leaf tem- perature and leaf water potential are of the type of rectangular hyperbola, parabola and ex- ponential curve, respectively. However, the stomata show little. response to air humidity. According to the response of stomata to light intensity, an attempt has been made to calculate the canopy conductace. A model simulating the water relations in Soil-Plant-Atmosphere Continuum (SPAC) have been established, and is called SMWBW (Simplified Model for the Water Balance of Wheat). The. parameters determined from the measurements are used in this model. The model can be used to pre- dict transpiration rate, canopy conductance, leaf temperature, and leaf water potential, pro- vided that the data of solar radiation, air tem- perature, humidity and wind speed are given. The predicted values agree with the observed data moderately well. It has been calculated that leaf water po- tential of wheat is not influenced very much by diurnal changes of leaf soluble sugar content.