Process-based coupled model of stomatal conductance–photosynthesis–transpiration was developed to estimate simultaneously stomatal conductance g_sw, photosynthetic rate P_n, and transpiration rate T_r during leaf ontogeny. The modified Jarvis model was constructed by superposing the influence of leaf age LA on g_sw in traditional Jarvis model. And the modified Farquhar model was constructed by incorporating the relationships of the LA with parameters in Farquhar model into traditional Farquhar model. The average and leaf-age-based coupled models were constructed, respectively, by combining traditional Farquhar and Penman–Monteith models with traditional Jarvis, and combining modified Farquhar and Penman–Monteith models with modified Jarvis. The results showed that the g_sw, the maximum rate of carboxylation, maximum rate of electron transport, rate of triose phosphates utilization, and mitochondrial respiration rate varied in a positive skew pattern, while the mesophyll diffusion conductance decreased linearly with increase in LA. The average coupled model underestimated g_sw, P_n, and T_r for young leaves and overestimated g_sw, P_n, and T_r for old leaves. And the leaf-age-based coupled model generally perfected well in estimating g_sw, P_n, and T_r for all leaves during leaf ontogeny. The study will provide basic information for either modeling leaf g_sw, P_n, and T_r continuously, or upscaling them from leaf to canopy scale by considering the variation of LA within canopy.

开发了基于过程的气孔导度-光合作用-蒸腾耦合模型，以同时估计叶片个体发育过程中的气孔导度g _sw、光合速率P _n和蒸腾速率T _r。通过叠加传统Jarvis模型中叶龄LA对g _sw的影响，构建了改进的Jarvis模型。并结合LA的关系构建了修正的 Farquhar 模型将 Farquhar 模型中的参数转换为传统的 Farquhar 模型。通过将传统的 Farquhar 和 Penman-Monteith 模型与传统的 Jarvis 相结合，以及将改进的 Farquhar 和 Penman-Monteith 模型与改进的 Jarvis 相结合，分别构建了基于平均和基于叶龄的耦合模型。结果表明，g _sw、最大羧化速率、最大电子传递速率、丙糖磷酸利用速率和线粒体呼吸速率呈正偏态变化，而叶肉扩散电导随LA 的增加呈线性下降。平均耦合模型低估了g _sw、P _n和T _r对于幼叶，高估了老叶的g _sw、P _n和T _r。并且基于叶龄的耦合模型在估计叶子个体发育过程中所有叶子的g _sw、P _n和T _{r 方面}通常非常完善。该研究将为连续模拟叶片g _sw、P _n和T _r提供基本信息，或者通过考虑冠层内LA的变化将它们从叶片放大到冠层尺度。