Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Optimal nitrogen-to-phosphorus stoichiometry of phytoplankton

Abstract

Redfield noted the similarity between the average nitrogen-to-phosphorus ratio in plankton (N:P = 16 by atoms) and in deep oceanic waters (N:P = 15; refs 1, 2). He argued that this was neither a coincidence, nor the result of the plankton adapting to the oceanic stoichiometry, but rather that phytoplankton adjust the N:P stoichiometry of the ocean to meet their requirements through nitrogen fixation, an idea supported by recent modelling studies3,4. But what determines the N:P requirements of phytoplankton? Here we use a stoichiometrically explicit model of phytoplankton physiology and resource competition to derive from first principles the optimal phytoplankton stoichiometry under diverse ecological scenarios. Competitive equilibrium favours greater allocation to P-poor resource-acquisition machinery and therefore a higher N:P ratio; exponential growth favours greater allocation to P-rich assembly machinery and therefore a lower N:P ratio. P-limited environments favour slightly less allocation to assembly than N-limited or light-limited environments. The model predicts that optimal N:P ratios will vary from 8.2 to 45.0, depending on the ecological conditions. Our results show that the canonical Redfield N:P ratio of 16 is not a universal biochemical optimum, but instead represents an average of species-specific N:P ratios.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Structural N:P ratio of 29 species of freshwater and marine phytoplankton.
Figure 2: Fitness measures as a function of allocation to assembly machinery.

References

  1. 1

    Redfield, A. C. The biological control of chemical factors in the environment. Am. Sci. 46, 205–221 (1958)

    CAS  Google Scholar 

  2. 2

    Falkowski, P. G. Rationalizing elemental ratios in unicellular algae. J. Phycol. 36, 3–6 (2000)

    CAS  Article  Google Scholar 

  3. 3

    Tyrrell, T. The relative influences of nitrogen and phosphorus on oceanic primary production. Nature 400, 525–531 (1999)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Lenton, T. M. & Watson, A. J. Redfield revisited 1. Regulation of nitrate, phosphate, and oxygen in the ocean. Glob. Biogeochem. Cycles 14, 225–248 (2001)

    ADS  Article  Google Scholar 

  5. 5

    Rhee, G.-Y. Effects of N:P atomic ratios and nitrate limitation on algal growth, cell composition and nitrate uptake. Limnol. Oceanogr. 23, 10–25 (1978)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Sterner, R. W. & Elser, J. J. Ecological Stoichiometry: The Biology of Elements from Molecules to the Biosphere (Princeton Univ. Press, Princeton, 2002)

    Google Scholar 

  7. 7

    Klausmeier, C. A., Litchman, E. & Levin, S. A. Phytoplankton growth and stoichiometry under multiple nutrient limitation. Limnol. Oceanogr. (in the press)

  8. 8

    Rhee, G.-Y. & Gotham, I. J. Optimum N:P ratios and coexistence of planktonic algae. J. Phycol. 16, 486–489 (1980)

    CAS  Article  Google Scholar 

  9. 9

    Bertilsson, S., Berglund, O., Karl, D. M. & Chisholm, S. W. Elemental composition of marine Prochlorococcus and Synechococcus: implications for the ecological stoichiometry of the sea. Limnol. Oceanogr. 48, 1721–1731 (2003)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Heldal, M., Scanlan, D. J., Norland, S., Thingstad, F. & Mann, N. H. Elemental composition of single cells of various strains of marine Prochlorococcus Synechococcus using X-ray microanalysis. Limnol. Oceanogr. 47, 1732–1743 (2003)

    ADS  Article  Google Scholar 

  11. 11

    Elser, J. J., Dobberfuhl, D., MacKay, N. A. & Schampel, J. H. Organism size, life history, and N:P stoichiometry: towards a unified view of cellular and ecosystem processes. BioScience 46, 674–684 (1996)

    Article  Google Scholar 

  12. 12

    Geider, R. J. & LaRoche, J. Redfield revisited: variability of C:N:P in marine microalgae and its biochemical basis. Eur. J. Phycol. 37, 1–17 (2002)

    Article  Google Scholar 

  13. 13

    Shuter, B. J. A model of physiological adaptation in unicellular algae. J. Theor. Biol. 78, 519–552 (1979)

    CAS  Article  Google Scholar 

  14. 14

    Kooijman, S. A. L. M. Dynamic Energy and Mass Budgets in Biological Systems 2nd edn (Cambridge Univ. Press, UK, 2000)

    Book  Google Scholar 

  15. 15

    Tilman, D. Resource Competition and Community Structure (Princeton Univ. Press, NJ, 1982)

    Google Scholar 

  16. 16

    Letelier, R. M. & Karl, D. M. Role of Trichodesmium spp. in the productivity of the subtropical North Pacific Ocean. Mar. Ecol. Prog. Ser. 133, 263–273 (1996)

    ADS  Article  Google Scholar 

  17. 17

    Hutchinson, G. E. The paradox of the plankton. Am. Nat. 95, 137–145 (1961)

    Article  Google Scholar 

  18. 18

    Tilman, D. & Pacala, S. in Species Diversity in Ecological Communities (eds Ricklets, R. & Schluter, D.) 13–25 (Univ. Chicago Press, Chicago, 1993)

    Google Scholar 

  19. 19

    Droop, M. R. The nutrient status of algal cells in continuous culture. J. Mar. Biol. Assoc. UK 54, 825–855 (1974)

    CAS  Article  Google Scholar 

  20. 20

    Litchman, E. & Klausmeier, C. A. Competition of phytoplankton under fluctuating light. Am. Nat. 157, 170–187 (2001)

    CAS  Article  Google Scholar 

  21. 21

    Broecker, W. S. & Henderson, G. M. The sequence of events surrounding Termination II and their implications for the cause of glacial-interglacial CO2 changes. Paleoceanogr. 13, 352–364 (1998)

    ADS  Article  Google Scholar 

  22. 22

    Pahlow, M. & Riebesell, U. Temporal trends in deep ocean Redfield ratios. Science 287, 831–833 (2001)

    ADS  Article  Google Scholar 

  23. 23

    Copin-Montegut, C. & Copin-Montegut, G. Stoichiometry of carbon, nitrogen, and phosphorus in marine particulate matter. Deep-Sea Res. 30, 31–46 (1983)

    ADS  CAS  Article  Google Scholar 

  24. 24

    Karl, D. M. et al. Ecological nitrogen-to-phosphorus stoichiometry at station ALOHA. Deep-Sea Res. II 48, 1529–1566 (2001)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Schneider, B., Schlitzer, R., Fischer, G. & Nöthig, E.-M. Depth-dependent elemental compositions of particulate organic matter (POM) in the ocean. Glob. Biogeochem. Cycles 17, 1032 (2003)

    ADS  Article  Google Scholar 

  26. 26

    Quigg, A. et al. The evolutionary inheritance of elemental stoichiometry in marine phytoplankton. Nature 425, 291–294 (2003)

    ADS  CAS  Article  Google Scholar 

  27. 27

    Behrenfeld, M. J. & Falkowski, P. G. A consumer's guide to phytoplankton primary productivity models. Limnol. Oceanogr. 42, 1479–1491 (1997)

    ADS  Article  Google Scholar 

  28. 28

    Kirk, J. T. O. & Tilney-Bassett, R. A. E. The Plastids: Their Chemistry, Structure, Growth and Inheritance 6 (Freeman Press, London, 1967)

    Google Scholar 

  29. 29

    Raven, J. A. Nutrient transport in microalgae. Ad. Microb. Physiol. 21, 147–226 (1980)

    Google Scholar 

  30. 30

    Aksnes, D. L. & Egge, J. K. A theoretical model for nutrient uptake in phytoplankton. Mar. Ecol. Prog. Ser. 70, 65–72 (1991)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We thank P. Falkowski, I. Loladze, S. Pacala and D. Tilman for comments and discussion. We acknowledge support from the Andrew W. Mellon Foundation and the National Science Foundation.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Christopher A. Klausmeier.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Information

Structural N:P ratio of 29 species of freshwater and marine phytoplankton. (PDF 39 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Klausmeier, C., Litchman, E., Daufresne, T. et al. Optimal nitrogen-to-phosphorus stoichiometry of phytoplankton. Nature 429, 171–174 (2004). https://doi.org/10.1038/nature02454

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing