Photosynthetic models sometimes incorporate meteorological elements typically recorded at a time interval of 10 min or 1 h. Because these data are calculated by averaging instantaneous values over time, short-term environmental fluctuations are concealed, which may affect outputs of the model. To assess an appropriate time interval of photosynthetic photon flux density (PPFD) measurement for accurate estimation of photosynthetic gain under open field conditions, we simulated the daily integral net photosynthetic gain using photosynthetic models with or without considering induction kinetics in response to changes in PPFD. Compared with the daily gain calculated from 60-min-interval PPFD data using a steady-state model that ignored the induction kinetics (i.e. a baseline gain), the gains simulated using higher-resolution PPFD data (10-s, 1-min, and 10-min intervals) and using a dynamic model that considered slow induction kinetics were both smaller by ~2%. The gain estimated by the slow dynamic model with 10-s-interval PPFD data was smaller than the baseline gain by more than 5% with a probability of 66%. Thus, the use of low-resolution PPFD data causes overestimation of daily photosynthetic gain in open fields. An appropriate time interval for PPFD measurement is 1 min or shorter to ensure accuracy of the estimates.

光合模型有时包含通常以 10 分钟或 1 小时的时间间隔记录的气象要素。因为这些数据是通过对一段时间内的瞬时值进行平均来计算的，所以短期环境波动被隐藏了，这可能会影响模型的输出。为了评估光合光子通量密度 (PPFD) 测量的适当时间间隔，以准确估计露天条件下的光合增益，我们使用光合模型模拟了每日积分净光合增益，考虑或不考虑响应 PPFD 变化的感应动力学。与使用忽略诱导动力学的稳态模型（即基线增益）从 60 分钟间隔 PPFD 数据计算的每日增益相比，使用更高分辨率的 PPFD 数据（10 秒、1 分钟、和 10 分钟间隔）并使用考虑慢诱导动力学的动态模型都小了约 2%。使用 10 秒间隔 PPFD 数据的慢速动态模型估计的增益比基线增益小 5% 以上，概率为 66%。因此，使用低分辨率 PPFD 数据会导致高估露天场地的每日光合增益。PPFD 测量的适当时间间隔为 1 分钟或更短，以确保估计的准确性。