Dynamic Model of Leaf Photosynthesis with Acclimation to Light and Nitrogen

A simple model of photosynthesis in a mature C₃leaf is described,based on a non-rectangular hyperbola: the model allows the high-lightasymptote of that equation (P_max) to respond dynamically tolight and nitrogen. This causes the leaf light response equationto acclimate continuously to the current conditions of lightand N nutrition, which can vary greatly within a crop canopy,and through a growing season, with important consequences forgross production. Predictions are presented for the dynamicsof acclimation, acclimated and non-acclimated photosyntheticrates are compared, and the dependence of leaf properties onlight and N availability is explored. There is good correspondenceof predictions with experimental results at the leaf level.The model also provides a mechanism for a down regulation ofphotosynthesis in response to increased carbon dioxide concentrations,whose magnitude will depend on conditions, particularly of nitrogennutrition.Copyright 1998 Annals of Botany Company Leaf, photosynthesis, hyperbola, model, C₃, acclimation, light, nitrogen.