U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Roadmap for Improving the Representation of Photosynthesis in Earth System Models
Published: November 28, 2016
Posted: November 29, 2016

Researchers identified key model development activities, data needs, and process knowledge improvements required to advance the representation of photosynthesis in next-generation climate models.

The Science 
A collaboration between modelers and plant physiologists compared the projected physiological responses of photosynthesis to key environmental drivers in seven terrestrial biosphere models (TBMs) that form the land components of major Earth system models. The study identified research activities needed to improve process representation of photosynthesis in TBMs.

The Impact
A widely held assumption is that the representation of photosynthesis in TBMs is settled science and that model uncertainty is driven largely by other processes downstream of carbon acquisition. This study demonstrates that model divergence in the physiological response of photosynthesis to key environmental drivers is high and likely a major source of model divergence. This finding is critical because the response of the terrestrial biosphere to global change is driven by these same physiological responses and their accurate representation should be an essential component of improved TBMs. This study lays out the steps needed to improve model representation of photosynthesis.

Accurate representation of photosynthesis in TBMs is essential for robust projections of global change. However, current representations vary markedly between TBMs, contributing uncertainty to projections of global carbon fluxes. In this study, researchers compared the representation of photosynthesis in seven TBMs by examining leaf and canopy-level responses of photosynthetic carbon dioxide (CO2) assimilation to key environmental variables: light, temperature, CO2 concentration, vapor pressure deficit, and soil water content. They identified research areas where limited process knowledge prevents inclusion of physiological phenomena in current TBMs and research areas where data are urgently needed for model parameterization or evaluation. The study provides a roadmap for new science needed to improve the representation of photosynthesis in the next generation of terrestrial biosphere and Earth system models.

Contacts (BER PM)
Daniel Stover and Jared DeForest
Daniel.Stover@science.doe.gov, 301-903-0289; and Jared.DeForest@science.doe.gov, 301-903-1678

(PI Contact)
Alistair Rogers
Brookhaven National Laboratory

The New Phytologist Trust provided support of the 9th New Phytologist Workshop: Improving Representation of Photosynthesis in Earth System Models. AR and SPS were supported by the Next-Generation Ecosystem Experiments (NGEE; NGEE-Arctic and NGEE-Tropics) projects funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research through contract number DE-SC00112704 to Brookhaven National Laboratory. DW acknowledges support from the Natural Sciences and Engineering Research Council, Canada Foundation for Innovation, and an Ontario Early Researcher Award. JSD received support from the National Science Foundation (DEB-0955771).

Rogers, A., B. E. Medlyn, and J. S. Dukes. 2014. “Improving Representation of Photosynthesis in Earth System Models,” New Phytologist 204, 12-14. DOI: 10.1111/nph.12972. (Reference link)

Rogers, A., B. E. Medlyn, J. S. Dukes, G. Bonan, et al. 2017. “A Roadmap for Improving Representation of Photosynthesis in Earth System Models,” New Phytologist 213, 22-42. DOI: 10.1111/nph.14283. (Reference link)

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Carbon Cycle, Nutrient Cycling

Division: SC-23.1 Climate and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)