Improving ecophysiological simulation models to predict the impact of elevated atmospheric CO2 concentration on crop productivity

Background

Process-based ecophysiological crop models are pivotal in assessing responses of crop productivity and designing strategies of adaptation to climate change. Most existing crop models generally over-estimate the effect of elevated atmospheric CO₂], despite decades of experimental research on crop growth response to CO₂].

Analysis

A review of the literature indicates that the quantitative relationships for a number of traits, once expressed as a function of internal plant nitrogen status, are altered little by the elevated CO₂]. A model incorporating these nitrogen-based functional relationships and mechanisms simulated photosynthetic acclimation to elevated CO₂], thereby reducing the chance of over-estimating crop response to CO₂]. Robust crop models to have small parameterization requirements and yet generate phenotypic plasticity under changing environmental conditions need to capture the carbon–nitrogen interactions during crop growth.

Conclusions

The performance of the improved models depends little on the type of the experimental facilities used to obtain data for parameterization, and allows accurate projections of the impact of elevated CO₂] and other climatic variables on crop productivity.