GLYCIM is a comprehensive soybean crop simulator that simulates soil, plant, and atmospheric interactions at the physical and physiological process level. The current research focused on replacing the original photosynthesis equation with a leaf-level coupled energy balance model of photosynthesis, transpiration, and stomatal conductance to more accurately simulate responses to climate change. Soybean gas exchange and growth data from six SPAR (Soil–Plant–Atmosphere Research) chamber experiments at four temperature treatments (24/18 °C, 28/22 °C, 32/26 °C, and 36/30 °C, respectively) under ambient (457 µmol mol⁻¹) CO₂ and two temperature treatments (28/22 °C and 32/26 °C, respectively) under elevated (670 µmol mol⁻¹) CO₂ were used to evaluate the ability of two GLYCIM model versions, original and modified, for simulating the responses of canopy photosynthesis, transpiration rates and observed harvest data. Simulation results showed that the modified GLYCIM had significantly better agreement with observed canopy photosynthetic and transpiration rates, as exhibited by higher values of IA (seasonal photosynthesis, average 0.86 versus 0.82; transpiration, average 0.95 versus 0.84) and lower values of RMSE (seasonal photosynthesis, average 0.58 versus 0.64 mol CO₂ m⁻² season⁻¹; transpiration, average 1.99 versus 3.16 mmol H₂O m⁻² s⁻¹) when compared to the original GLYCIM. The simulation of carbon partitioning to stems, leaves, pod and seed was reasonably accurate for both versions, although leaf and stem growth were under-predicted at warmest temperature treatments at either CO₂ level. Overall, the modified GLYCIM provided an improved fit of gas exchange and dry matter over a broad range of temperatures and CO₂ levels. Given additional evaluation with field data, these improvements will be useful to study adaptation responses for projected warmer, CO₂ enriched, climate.

GLYCIM 是一种综合性大豆作物模拟器，可在物理和生理过程级别模拟土壤、植物和大气相互作用。目前的研究重点是用光合作用、蒸腾作用和气孔导度的叶级耦合能量平衡模型代替原来的光合作用方程，以更准确地模拟对气候变化的响应。来自六个 SPAR（土壤-植物-大气研究）室实验在四种温度处理（分别为 24/18 °C、28/22 °C、32/26 °C 和 36/30 °C）下的大豆气体交换和生长数据) 在环境 (457 µmol mol ^-1 ) CO _{2 下}和在升高 (670 µmol mol ^-1 ) CO ₂下进行两次温度处理（分别为 28/22 °C 和 32/26 °C ）用于评估原始和修改的两个 GLYCIM 模型版本的能力，用于模拟冠层光合作用、蒸腾速率和观察到的收获数据的响应。模拟结果表明，改进的 GLYCIM 与观察到的冠层光合和蒸腾速率具有更好的一致性，表现为较高的 IA（季节性光合作用，平均 0.86 对 0.82；蒸腾作用，平均 0.95 对 0.84）和较低的 RMSE（季节性光合作用）值，平均 0.58 对 0.64 mol CO ₂ m ^-2季节^-1；蒸腾作用，平均 1.99 对 3.16 mmol H ₂ O m ^-2  s ^-1) 与原始 GLYCIM 相比。碳分配到茎、叶、豆荚和种子的模拟对于两个版本都相当准确，尽管在任一 CO ₂水平的最温暖温度处理下，叶和茎的生长都被低估了。总体而言，改进的 GLYCIM 在广泛的温度和 CO ₂水平范围内提供了更好的气体交换和干物质拟合。如果对现场数据进行额外评估，这些改进将有助于研究预测的更温暖、富含CO _{2 的}气候的适应反应。