Triose phosphate limitation in photosynthesis models reduces leaf photosynthesis and global terrestrial carbon storage
Triose phosphate utilization (TPU)-limited photosynthesis occurs when carbon export from the Calvin-Benson cycle cannot keep pace with carbon inputs and processing. This condition is poorly constrained by observations but may become an increasingly important driver of global carbon cycling under future climate scenarios. However, the consequences of including or omitting TPU limitation in models have seldom been quantified. In this work, we assess the impact of changing the representation of TPU limitation on leaf- and global-scale processes. At the leaf scale, TPU limits photosynthesis at cold temperatures, high CO2 concentrations, and high light levels. Consistent with leaf-scale results, global simulations using the Community Land Model version 4.5 illustrate that the standard representation of TPU limits carbon gain under present day and future conditions, most consistently at high latitudes. If the assumed TPU limitation is doubled, further restricting photosynthesis, terrestrial ecosystem carbon pools are reduced by 9 Pg by 2100 under a business-as-usual scenario. The impact of TPU limitation on global terrestrial carbon gain suggests that CO2 concentrations may increase more than expected if models omit TPU limitation, and highlights the need to better understand when TPU limitation is important, including variation among different plant types and acclimation to temperature and CO2.
- Research Organization:
- Univ. of Michigan, Ann Arbor, MI (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States); Michigan State Univ., East Lansing, MI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); USDA; National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES); National Institute of Food and Agriculture (NIFA)
- Grant/Contract Number:
- FC03-97ER62402/A010; FG02-91ER2002; SC0012704; SC0012972; 2015-67003-23485; FC03-97ER62402/377 A010; 2015-67003-23489; 1049033; 1000026; FG02-91ER20021
- OSTI ID:
- 1459720
- Alternate ID(s):
- OSTI ID: 1459167; OSTI ID: 1603664
- Report Number(s):
- BNL-206806-2018-JAAM
- Journal Information:
- Environmental Research Letters, Journal Name: Environmental Research Letters Vol. 13 Journal Issue: 7; ISSN 1748-9326
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
Web of Science
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