Acclimation and adaptation components of the temperature dependence of plant photosynthesis at the global scale

Abstract

Summary The temperature response of photosynthesis is one of the key factors determining predicted responses to warming in global vegetation models (GVMs). The response may vary geographically, owing to genetic adaptation to climate, and temporally, as a result of acclimation to changes in ambient temperature. Our goal was to develop a robust quantitative global model representing acclimation and adaptation of photosynthetic temperature responses. We quantified and modelled key mechanisms responsible for photosynthetic temperature acclimation and adaptation using a global dataset of photosynthetic CO2 response curves, including data from 141 C3 species from tropical rainforest to Arctic tundra. We separated temperature acclimation and adaptation processes by considering seasonal and common‐garden datasets, respectively. The observed global variation in the temperature optimum of photosynthesis was primarily explained by biochemical limitations to photosynthesis, rather than stomatal conductance or respiration. We found acclimation to growth temperature to be a stronger driver of this variation than adaptation to temperature at climate of origin. We developed a summary model to represent photosynthetic temperature responses and showed that it predicted the observed global variation in optimal temperatures with high accuracy. This novel algorithm should enable improved prediction of the function of global ecosystems in a warming climate.

How do vascular plants perform photosynthesis in extreme environments? An integrative ecophysiological and biochemical story

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Leaf reflectance spectroscopy captures variation in carboxylation capacity across species, canopy environment and leaf age in lowland moist tropical forests

“…This assumption is most questionable for the tropical forest biome where forests hold enormous plant functional diversity (Condit et al ., ; Steege et al ., ; Asner et al ., ) that includes diversity in photosynthetic capacity (Norby et al ., ; Walker et al ., ). Furthermore, for a given species, V c,max25 has been shown to vary greatly with leaf development, growth temperature, and water and nutrient availability (Medlyn et al ., ; Wilson et al ., ; Kenzo et al ., ; Kattge & Knorr, ; Ali et al ., ; Norby et al ., ; Albert et al ., ; Kumarathunge et al ., ; Smith et al ., ). Recently it was shown that the seasonality of photosynthesis in Amazonian evergreen forests, a c .…”

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