An eco-evolutionary optimality model explains the acclimated temperature response of photosynthesis

Gan, W., Alizadeh, N., Best, M., Vidale, P. L. ORCID: https://orcid.org/0000-0002-1800-8460, Prentice, I. C. and Harrison, S. P. ORCID: https://orcid.org/0000-0001-5687-1903 (2026) An eco-evolutionary optimality model explains the acclimated temperature response of photosynthesis. New Phytologist. ISSN 1469-8137 doi: 10.1111/nph.71062 (In Press)

Abstract/Summary

The optimal temperature of photosynthesis (Topt) generally increases with plant growth temperature. Changes in Topt are associated with changes in the maximum carboxylation capacity at 25°C (Vcmax25) and the maximum electron transport rate at 25°C (Jmax25). The ratio between Jmax25 and Vcmax25 declines with warming. Accurate representation of leaf-level photosynthetic responses to temperature is essential for realistic projections of the terrestrial carbon cycle and its response to ongoing climate changes. However, many land surface models incorporate thermal acclimation through empirical approaches and through assigning distinct but static parameter values to plant functional types (PFTs). Eco-evolutionary optimality (EEO) approaches provide a simpler way of modelling photosynthesis without recourse to PFTs. Here, we use the subdaily P model, an EEO-based model of photosynthesis that explicitly separates the instantaneous and acclimated responses of photosynthetic parameters to temperature to investigate how optimal temperature changes with growth temperature, as represented by leaf or air temperature. We show that the simulated responses are consistent with observations from both controlled experiments and eddy covariance flux tower data. We show that changes in Topt, and in the assimilation rate at Topt, are caused by changes in carboxylation capacity and electron transport rate that follow directly from the hypotheses underlying the model.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/129458
Identification Number/DOI	10.1111/nph.71062
Refereed	Yes
Divisions	Science > School of Archaeology, Geography and Environmental Science > Department of Geography and Environmental Science
Publisher	Wiley
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