Skip to main content
Article thumbnail
Location of Repository

Simulation of carbon isotope discrimination of the terrestrial biosphere

By Neil S. Suits, A. Scott Denning, J. A. Berry, C. J. Still, Jörg Kaduk, J. B. Miller and I.T. Baker


We introduce a multistage model of carbon isotope discrimination during C3 photosynthesis and global maps of C3/C4 plant ratios to an ecophysiological model of the terrestrial biosphere (SiB2) in order to predict the carbon isotope ratios of terrestrial plant carbon globally at a 1° resolution. The model is driven by observed meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), constrained by satellite-derived Normalized Difference Vegetation Index (NDVI) and run for the years 1983–1993. Modeled mean annual C3 discrimination during this period is 19.2‰; total mean annual discrimination by the terrestrial biosphere (C3 and C4 plants) is 15.9‰. We test simulation results in three ways. First, we compare the modeled response of C3 discrimination to changes in physiological stress, including daily variations in vapor pressure deficit (vpd) and monthly variations in precipitation, to observed changes in discrimination inferred from Keeling plot intercepts. Second, we compare mean δ13C ratios from selected biomes (Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal) to the observed values from Keeling plots at these biomes. Third, we compare simulated zonal δ13C ratios in the Northern Hemisphere (20°N to 60°N) to values predicted from high-frequency variations in measured atmospheric CO2 and δ13C from terrestrially dominated sites within the NOAA-Globalview flask network. The modeled response to changes in vapor pressure deficit compares favorably to observations. Simulated discrimination in tropical forests of the Amazon basin is less sensitive to changes in monthly precipitation than is suggested by some observations. Mean model δ13C ratios for Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal biomes compare well with the few measurements available; however, there is more variability in observations than in the simulation, and modeled δ13C values for tropical forests are heavy relative to observations. Simulated zonal δ13C ratios in the Northern Hemisphere capture patterns of zonal δ13C inferred from atmospheric measurements better than previous investigations. Finally, there is still a need for additional constraints to verify that carbon isotope models behave as expected

Publisher: American Geophysical Union (AGU)
Year: 2005
DOI identifier: 10.1029/2003GB002141
OAI identifier:

Suggested articles


  1. (1994). (red line), Fung et al. [1997] (green line), and this study (blue line).
  2. (1994). 13C discrimination during CO2 assimilation by the terrestrial biosphere, doi
  3. (1999). A 1000-year high precision record of d13C in atmospheric CO2, doi
  4. (1980). A biochemical model of photosynthetic CO2 assimilation in C3 plants, doi
  5. (2000). A global 9-year biophysical landsurface dataset from NOAA AVHRR data, doi
  6. (1985). A global archive of landcover and soils data for use in general circulation climate models, doi
  7. (1999). A global calculation of d13C of soil respired carbon: Implications for the biospheric uptake of anthropogenic CO2, doi
  8. (1996). A land surface model (LSM version 1.0) for ecological, hydrological, and atmospheric studies: Technical description and user’s guide, NCAR/TN-417+STR, Natl. Cent. for Atmos.
  9. (1961). A mechanism for cyclic enrichment of carbon-12 by terrestrial plants, doi
  10. (1989). A model to estimate carbon dioxide recycling in forests using 13C/12C ratios and concentrations of ambient carbon dioxide, doi
  11. (2004). A multiple-scale simulation of variations in atmospheric carbon dioxide using a coupled biosphere-atmosphere model, doi
  12. (1999). A new global 1 km data set of percent tree cover derived from remote sensing, doi
  13. (1996). A revised land surface parameterization (SiB2) for atmospheric GCMs: I. Model formulation, doi
  14. (1996). A revised land surface parameterization (SiB2) for GCMs: III. The greening of the Colorado State University general circulation model, doi
  15. (1986). A simple biosphere model (SiB) for use within general circulation models, doi
  16. (1995). A synthesis inversion of the concentration and d13C of atmospheric CO2, doi
  17. (1989). A three-dimensional model of CO2 transport based on observed winds: 1. Analysis of observational data, doi
  18. (2000). Acquisition and diffusion of CO2 in higher plant leaves, in Photosynthesis: Physiology and Metabolism, edited by doi
  19. (1998). Agriculture Organization doi
  20. (1997). An alternative interpretation of the appropriateness and correct means for the evaluation of CO2 recycling indices, doi
  21. (1988). An analysis of stomatal conductance,
  22. (1986). Aworld soil file for global climate modeling,
  23. (1993). Biochemical basis of carbon isotope fractionation in plants, in Stable Isotopes and Plant Carbon Water Relations, doi
  24. (1985). Cape Grim isotope measurements—A preliminary assessment, doi
  25. (1998). Carbon and nitrogen isotope discrimination and nitrogen nutrition of trees along a rainfall gradient in northern Australia, doi
  26. (1997). Carbon dioxide recycling in two Amazonian tropical forests, doi
  27. (2003). Carbon in Amazon forests: Unexpected seasonal fluxes and disturbance-induced losses, doi
  28. (1988). Carbon isotope discrimination and plant water use efficiency, doi
  29. (2002). Carbon isotope discrimination in forest and pasture ecosystems of the Amazon Basin, Brazil, Global Biogeochem. doi
  30. (1974). Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide, doi
  31. (1981). Carbon isotope fractionation in plants, doi
  32. (1997). Carbon-13 exchanges between the atmosphere and biosphere, doi
  33. (1995). Changes in oceanic and terrestrial carbon uptake since doi
  34. (1998). Characterizing patterns of global land use: An analysis of global croplands data, doi
  35. (1992). Coupled photosynthesis-stomatal conductance model for leaves of C4 plants, doi
  36. (1985). d13C variations of leaves in forests as an indication of reassimilated CO2 from the soil, doi
  37. Dazlich (1996a), Simulations of terrestrial carbon metabolism and atmospheric CO2 in a general circulation model: 1. Surface carbon fluxes, doi
  38. (1998). Determination of the isotopic (13C/12C) discrimination by terrestrial biology from a global network of observations, doi
  39. (1996). Diversity, metabolic types and d13C carbon isotope ratios in grass flora of Namibia in relation to growth form, precipitation and habitat conditions, doi
  40. (1998). Effect of interannual climate change on carbon storage in Amazonian ecosystems,
  41. (1998). Effects of climate and atmospheric CO2 partial pressure on the global distribution of C-4 grasses: Present, past, and future, doi
  42. Ehleringer (1997a), Interseasonal comparison of CO2 concentrations, isotopic composition, and carbon dynamics in an Amazonian rainforest doi
  43. Ehleringer (1997b), Influence of stand structure on carbon-13 of vegetation, soils, and canopy air within deciduous and evergreen forests in Utah, doi
  44. Ehleringer (2002), 13C content of ecosystem respiration is linked to precipitation and vapor pressure deficit, doi
  45. (1999). Elevated CO2 and temperature impacts on different components of soil CO2 flux in Douglass Fir terracosms, doi
  46. (1996). Fluxes of CO2 and water fluxes between terrestrial vegetation and the atmosphere estimated from isotope measurements, doi
  47. Francey (1995a), A large Northern Hemisphere terrestrial sink induced by the 13C/12C ratio of atmospheric CO2, doi
  48. (2000). Global continuous fields of vegetation characteristics: A linear mixture model applied to multiyear 8 km AVHRR data, doi
  49. (1998). Global land cover classifications at 8 km spatial resolution: The use of training data derived from Landsat imagery in decision tree classifiers, doi
  50. Hansen (1999a), Continuous fields of vegetation characteristics at the global scale at 1-km resolution, doi
  51. (1989). Hubick doi
  52. (1993). Implications for plant breeding of genotypic and drought induced differences in water use efficiency, carbon isotope discrimination and gas exchange, in Stable Isotopes and Plant Carbon-Water Relations, doi
  53. (1995). Interannual extremes in the rate of rise of atmospheric CO2 since doi
  54. (2001). Intergovernmental Panel on Climate Change doi
  55. (1999). Inverse modeling of annual atmospheric CO2 sources and sinks: 2. Sensitivity study, doi
  56. (1984). Isotopic composition of plant carbon correlates with water-use efficiency of wheat genotypes, doi
  57. (1957). Isotopic standards for carbon and oxygen and correction factors for mass-spectrometric analysis of carbon dioxide, doi
  58. (2001). Large-scale forest girdling shows that current photosynthesis drives soil respiration, doi
  59. (1997). Leaf d13C in Pinos resinosa trees and understory plants: Variation associated with light and CO2 gradients, doi
  60. (1998). Linkages between global vegetation and climate: An analysis based on NOAA advanced very high resolution radiometer data, report, NASA Goddard Space Flight Cent.,
  61. (1984). Measurement of the isotopic fractionation associated with diffusion of carbon dioxide in aqueous solution, doi
  62. (2001). Natural abundance of 13C in CO2 respired from forest soils reveals speed of link between tree photosynthesis and root respiration, doi
  63. (1994). NDVI-derived landcover classifications at global scale, doi
  64. (1993). Oceanic 13C data: A new window on CO2 uptake by the oceans, doi
  65. (1983). On the nature of carbon isotope discrimination in C4 species, doi
  66. (1982). On the relationship between carbon isotope discrimination and the intercellular carbon dioxide concentration in leaves, doi
  67. (2001). Partitioning net ecosystem carbon exchange with isotopic fluxes of CO2, doi
  68. (2000). Photosynthetic fractionation of carbon isotopes, in Photosynthesis: Physiology and Metabolism, edited by doi
  69. (1991). Physiological and environmental regulation of stomatal conductance, photosynthesis, doi
  70. Randall (1996b), A revised land surface parameterization (SiB2) for atmospheric GCMs: II. The generation of global fields of terrestrial biophysical parameters from satellite data, doi
  71. (1999). Reconstructing the recent carbon cycle from atmospheric CO2, d 13C and O2/N2 observations, doi
  72. (1993). Relationship between carbon isotope discrimination, water use efficiency and transpiration efficiency for dryland wheat, doi
  73. Schimel (1995b), Partitioning of ocean and land uptake of CO2 as inferred by d 13C measurements from the NOAA Climate Monitoring and Diagnostics Laboratory Global Air Sampling Network, doi
  74. Sellers (1996b), Simulations of terrestrial carbon metabolism and atmospheric CO2 in a general circulation model: 2. Spatial and temporal variations of atmospheric CO2, doi
  75. (1999). Separation of root respiration from total respiration using carbon-13 labeling during free air carbon dioxide enrichment (FACE), doi
  76. (2003). Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF-TV tower using SiB2.5, doi
  77. (2003). Simulated and observed variations in atmospheric carbon dioxide over a Wisconsin forest using a coupled ecosystem-atmosphere model, doi
  78. (2001). Spatial distribution of leaf water use efficiency and carbon isotope discrimination within an isolated tree crown, doi
  79. (1988). Studies of mechanisms affecting the fractionation of carbon isotopes in photosynthesis, doi
  80. (2003). The application and interpretation of Keeling plots in terrestrial carbon-cycle research, doi
  81. (2003). The atmospheric signal of terrestrial isotopic discrimination and its implication for partitioning of carbon fluxes, doi
  82. (1999). The biogeography of C4 photosynthesis: Patterns and controlling factors, doi
  83. (1992). The climate-induced variation on the continental biosphere: A model simulation of the Last Glacial Maximum, doi
  84. (1958). The concentration and isotopic abundances of atmospheric carbon dioxide in rural areas, doi
  85. (1953). The geochemistry of stable carbon isotopes, doi
  86. (1991). The IIASA climate database for mean monthly values of temperature, precipitation and cloudiness on a terrestrial grid (RR-9118), report,
  87. (1990). The influence of N metabolism and organic acid synthesis on the natural abundance of isotopes of carbon in plants, doi
  88. (1996). The ISLSCP initiative I global datasets: Surface boundary conditions and atmospheric forcings for land-atmosphere studies, doi
  89. (1998). The land surface climatology of the NCAR Land Surface Model coupled to the NCAR Community Climate Model, doi
  90. (2002). The stable carbon isotope composition of the terrestrial biosphere: Modeling at scales from the leaf to the globe, doi
  91. (1996). Vegetation effects on the isotopic composition of atmospheric CO2 at local and regional scales: Theoretical aspects and a comparison between rain forest in Amazonia and a boreal forest in Siberia, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.