Simulation of growth and development processes of spring wheat in response to CO2 and ozone for different sites and years in Europe using mechanistic crop simulation models.

摘要

Two modified mechanistic crop simulation models (AFRCWHEAT2-O3 and LINTULCC), which differ in the levels of mechanistic detail, were used to simulate the effects of CO2 (ambient and twice ambient) and ozone (ambient and 1.5 times ambient) on growthand development of spring wheat in response to climatic conditions. Simulations were analysed using data from the ESPACE-wheat project in which spring wheat cv. Minaret was grown in open-top chambers at 9 sites throughout Europe for up to 3 years at eachsite. Both models closely predicted phenological development and the average measured biomass at maturity. However, intermediate growth variables such as biomass and LAI at anthesis, seasonal accumulated photosynthetically active radiation intercepted by the crop (SIGMAIPAR), the average seasonal light use efficiency (LUE) and the light-saturated rate of flag leaf photosynthesis (Asat) were predicted differently and less accurately by the 2 models. The effect of CO2 on the final biomass was underestimated by AFRCWHEAT2-O3 due to its poor simulation of the effect of CO2 on tillering, and LAI. LINTULCC overestimated the response of biomass production to changes in CO2 level due to an overprediction of the effect of CO2 on LUE. The measured effect of O3exposure on final biomass was predicted accurately by the 2 models. The models also simulated the observed interactive effect of CO2 and O3 on biomass production. However, the effects of O3 on LAI, SIGMAIPAR and Asat were simulated differently by the models and less accurately with LINTULCC for the O3 effects on LAI and SIGMAIPAR. Predictions of the variation between sites and years of growth and development parameters and of their responses to CO2 and O3 were poor for both AFRCWHEAT2-O3 and LINTULCC. It was concluded that other factors than those considered in the models, such as chamber design and soil properties, may have affected the growth and development of wheat. An analysis of the relationships between growth parameters calculated from the simulations supported this conclusion.