Abstract. Tropospheric ozone (O3) is the third most important
anthropogenic greenhouse gas. O3 is detrimental to plant productivity,
and it has a significant impact on crop yield. Currently, the Joint UK Land
Environment Simulator (JULES) land surface model includes a representation
of global crops (JULES-crop) but does not have crop-specific O3 damage
parameters and applies default C3 grass O3 parameters for soybean that
underestimate O3 damage. Physiological parameters for O3 damage
in soybean in JULES-crop were calibrated against leaf gas-exchange
measurements from the Soybean Free Air Concentration Enrichment (SoyFACE)
with O3 experiment in Illinois, USA. Other plant parameters were
calibrated using an extensive array of soybean observations such as crop
height and leaf carbon and meteorological data from FLUXNET sites near
Mead, Nebraska, USA. The yield, aboveground carbon, and leaf area index (LAI)
of soybean from the SoyFACE experiment were used to evaluate the newly
calibrated parameters. The result shows good performance for yield, with the
modelled yield being within the spread of the SoyFACE observations. Although
JULES-crop is able to reproduce observed LAI seasonality, its magnitude is
underestimated. The newly calibrated version of JULES will be applied
regionally and globally in future JULES simulations. This study helps to
build a state-of-the-art impact assessment model and contribute to a more
complete understanding of the impacts of climate change on food production.
Free-Air Concentration Enrichment (FACE) techniques, experimental approach and its application in the field of global change ecology: a review