Murakami Keach, Jishi Tomohiro
Hokkaido Agricultural Research Center (HARC), National Agriculture and Food Research Organisation (NARO), 062-8555, 1 Hitsujigaoka, Toyohira, Sapporo, Japan; and Corresponding author.
Energy Innovation Center, Central Research Institute of Electric Power Industry, 270-1194, 1646 Abiko, Abiko, Chiba, Japan.
Funct Plant Biol. 2022 May;49(6):452-462. doi: 10.1071/FP20323.
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.
光合模型有时会纳入通常以10分钟或1小时的时间间隔记录的气象要素。由于这些数据是通过对瞬时值进行时间平均计算得出的，短期环境波动被掩盖了，这可能会影响模型的输出。为了评估在开阔田间条件下准确估算光合增益时光合有效辐射（PPFD）测量的合适时间间隔，我们使用考虑或不考虑响应PPFD变化的诱导动力学的光合模型模拟了每日积分净光合增益。与使用忽略诱导动力学的稳态模型（即基线增益）从60分钟间隔的PPFD数据计算出的每日增益相比，使用更高分辨率的PPFD数据（10秒、1分钟和10分钟间隔）以及使用考虑缓慢诱导动力学的动态模型模拟的增益均小约2%。使用10秒间隔的PPFD数据的缓慢动态模型估计的增益比基线增益小超过5%的概率为66%。因此，使用低分辨率的PPFD数据会导致开阔田间每日光合增益的高估。PPFD测量的合适时间间隔为1分钟或更短，以确保估计的准确性。
