title: A roadmap for improving the representation of photosynthesis in Earth system models.
abstract: Accurate representation of photosynthesis in terrestrial biosphere models (TBMs) is essential for robust projections of global change. However, current representations vary markedly between TBMs, contributing uncertainty to projections of global carbon fluxes. Here we compared the representation of photosynthesis in seven TBMs by examining leaf and canopy level responses of photosynthetic CO2assimilation (A) to key environmental variables: light, temperature, CO2concentration, vapor pressure deficit and soil water content. We 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. We provide a roadmap for new science needed to improve the representation of photosynthesis in the next generation of terrestrial biosphere and Earth system models.
authors.affiliation: Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA.
authors.forename: Alistair
authors.initials: A
authors.lastname: Rogers
authors.affiliation: Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, NSW, 2751, Australia.
authors.forename: Belinda E
authors.initials: BE
authors.lastname: Medlyn
authors.affiliation: Department of Forestry and Natural Resources and Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907-2061, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Dukes
authors.affiliation: National Center for Atmospheric Research, Boulder, CO, 80307-3000, USA.
authors.forename: Gordon
authors.initials: G
authors.lastname: Bonan
authors.affiliation: Research School of Biology, College of Medicine, Biology and the Environment, The Australian National University, Linnaeus Building (Bldg 134) Linnaeus Way, Canberra, ACT, 0200, Australia.
authors.forename: Susanne
authors.initials: S
authors.lastname: von Caemmerer
authors.affiliation: Department of Earth and Environment, Boston University, Boston, MA, 02215, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Dietze
authors.affiliation: Max Planck Institute for Biogeochemistry, 07701, Jena, Germany.|German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Kattge
authors.affiliation: Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Andrew D B
authors.initials: AD
authors.lastname: Leakey
authors.affiliation: Geography Department, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK.|Center for Ecology and Hydrology, Wallingford, OX10 8BB, UK.
authors.forename: Lina M
authors.initials: LM
authors.lastname: Mercado
authors.affiliation: Department of Plant Physiology, Estonian University of Life Sciences, Kreutzwaldi 1, 51014, Tartu, Estonia.
authors.forename: Ülo
authors.initials: Ü
authors.lastname: Niinemets
authors.affiliation: AXA Chair of Biosphere and Climate Impacts, Grand Challenges in Ecosystems and the Environment and Grantham Institute for Climate Change, Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK.|Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.|State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest Agriculture & Forestry University, Yangling, 712100, China.
authors.forename: I Colin
authors.initials: IC
authors.lastname: Prentice
authors.affiliation: Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA.
authors.forename: Shawn P
authors.initials: SP
authors.lastname: Serbin
authors.affiliation: Geography Department, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sitch
authors.affiliation: Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada.|Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA.
authors.forename: Danielle A
authors.initials: DA
authors.lastname: Way
authors.affiliation: Biogeochemical Integration Department, Max Planck Institute for Biogeochemistry, Hans-Knöll-Str. 10, 07745, Jena, Germany.
authors.forename: Sönke
authors.identifier: 0000-0001-5602-7956
authors.initials: S
authors.lastname: Zaehle
mesh_terms: D018534:Earth, Planet; D017753:Ecosystem; D008954:Models, Biological; D010788:Photosynthesis; D018515:Plant Leaves / Q000502:physiology; D055548:Vapor Pressure
keywords: carbon dioxide CO2; light; soil water content; stomatal conductance; temperature; terrestrial biosphere models; vapor pressure deficit (VPD)