Seasonal fluctuations and temperature dependence in photosynthetic parameters and stomatal conductance at the leaf scale of Populus euphratica Oliv

• Published in: Tree physiology Vol. 31; no. 2; pp. 178 - 195
• Main Authors: Zhu, G.-F., Li, X., Su, Y.-H., Lu, L., Huang, C.-L.
• Format: Journal Article
• Language: English
• Published: Canada 01.02.2011
• Subjects: Bayes Theorem; Biological Transport; China; Models, Biological; Photosynthesis; Plant Leaves - metabolism; Plant Stomata - metabolism; Populus - metabolism; Seasons; Temperature; China
• ISSN: 0829-318X; 1758-4469; 1758-4469
• DOI: 10.1093/treephys/tpr005

A combined model to simulate CO₂ and H₂O gas exchange at the leaf scale was parameterized using data obtained from in situ leaf-scale observations of diurnal and seasonal changes in CO₂ and H₂O gas exchange. The Farquhar et al.-type model of photosynthesis was parameterized by using the Bayesian approach and the Ball et al.-type stomatal conductance model was optimized using the linear least-squares procedure. The results show that the seasonal physiological changes in photosynthetic parameters (e.g., V(cmax25), J(max25), R(d25) and g(m25)) in the biochemical model of photosynthesis and m in the stomatal conductance model should be counted in estimating long-term CO₂ and H₂O gas exchange. Overall, the coupled model successfully reproduced the observed response in net assimilation and transpiration rates.