Estimating stomatal and biochemical limitations during photosynthetic induction

Abstract

Understanding stomatal and biochemical components that limit photosynthesis underdifferent conditions is important for both the targeted improvement of photosynthe-sis and the elucidation of how stomata and biochemistry affect plant performance inan ecological context. Limitation analyses have not yet been extensively applied toconditions of photosynthetic induction after an increase in irradiance. Moreover,few studies have systematically assessed how well various limitation analyses actuallywork. Here we build on two general ways of estimating limitations, one that sequen-tially removes the effect of a limitation (elimination) and one that uses a tangent planeapproximation (differential), by including the ternary effect and boundary layer con-ductance so that they are consistent with gas exchange data. We apply them to theanalysis of temporal and time‐integrated limitations during photosynthetic induction,calculating limitations either independent of the time course (one‐step) or make useof the entire time course (stepwise). We show that the stepwise differential methodis the best method to use when time steps are small enough. We further show thatthe differential method predicts limitations near exact when the internal CO2concen-tration stays constant. This last insight has important implications for the general useof limitation analyses beyond photosynthetic induction. Show more