Crassulacean acid metabolism (CAM) crops are important agricultural commodities in water‐limited environments across the globe, yet modelling of CAM productivity lacks the sophistication of widely used C3 and C4 crop models, in part due to the complex responses of the CAM cycle to environmental conditions. This work builds on recent advances in CAM modelling to provide a framework for estimating CAM biomass yield and water use efficiency from basic principles. These advances, which integrate the CAM circadian rhythm with established models of carbon fixation, stomatal conductance and the soil–plant‐atmosphere continuum, are coupled to models of light attenuation, plant respiration and biomass partitioning. Resulting biomass yield and transpiration for Opuntia ficus‐indica and Agave tequilana are validated against field data and compared with predictions of CAM productivity obtained using the empirically based environmental productivity index. By representing regulation of the circadian state as a nonlinear oscillator, the modelling approach captures the diurnal dynamics of CAM stomatal conductance, allowing the prediction of CAM transpiration and water use efficiency for the first time at the plot scale. This approach may improve estimates of CAM productivity under light‐limiting conditions when compared with previous methods.

中文翻译：

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进行Crassulacean酸代谢生产力和用水的非线性动力学建模，以进行全球预测

在全球缺水的环境中，山楂酸代谢（CAM）作物是重要的农业商品，但是CAM生产力的模型缺乏广泛使用的C3和C4作物模型的复杂性，部分原因是CAM循环对环境的复杂响应条件。这项工作建立在CAM建模的最新进展的基础上，为根据基本原理估算CAM生物量产量和用水效率提供了框架。这些进步将CAM昼夜节律与已建立的碳固定，气孔导度和土壤-植物-大气连续性模型相结合，并与光衰减，植物呼吸和生物量分配模型结合在一起。仙人掌和龙舌兰龙舌兰的生物量产量和蒸腾作用对照现场数据进行验证，并与使用基于经验的环境生产率指数获得的CAM生产率预测进行比较。通过将昼夜节律的状态表示为非线性振荡器，该建模方法可以捕获CAM气孔电导的昼夜动态，从而首次在样地尺度上预测CAM的蒸腾作用和水分利用效率。与以前的方法相比，此方法可能会改善在光限制条件下CAM生产率的估计。