The effect of permafrost thaw on old carbon release and net carbon exchange from tundra


Permafrost soils in boreal and Arctic ecosystems store almost twice as much carbon1,2 as is currently present in the atmosphere3. Permafrost thaw and the microbial decomposition of previously frozen organic carbon is considered one of the most likely positive climate feedbacks from terrestrial ecosystems to the atmosphere in a warmer world1,2,4,5,6,7. The rate of carbon release from permafrost soils is highly uncertain, but it is crucial for predicting the strength and timing of this carbon-cycle feedback effect, and thus how important permafrost thaw will be for climate change this century and beyond1,2,4,5,6,7. Sustained transfers of carbon to the atmosphere that could cause a significant positive feedback to climate change must come from old carbon, which forms the bulk of the permafrost carbon pool that accumulated over thousands of years8,9,10,11. Here we measure net ecosystem carbon exchange and the radiocarbon age of ecosystem respiration in a tundra landscape undergoing permafrost thaw12 to determine the influence of old carbon loss on ecosystem carbon balance. We find that areas that thawed over the past 15 years had 40 per cent more annual losses of old carbon than minimally thawed areas, but had overall net ecosystem carbon uptake as increased plant growth offset these losses. In contrast, areas that thawed decades earlier lost even more old carbon, a 78 per cent increase over minimally thawed areas; this old carbon loss contributed to overall net ecosystem carbon release despite increased plant growth. Our data document significant losses of soil carbon with permafrost thaw that, over decadal timescales, overwhelms increased plant carbon uptake13,14,15 at rates that could make permafrost a large biospheric carbon source in a warmer world.

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Figure 1: Net exchange of CO 2 between tundra and the atmosphere for three sites that differ in the extent of permafrost thaw.
Figure 2: Radiocarbon values of ecosystem respiration and the proportional contribution from old carbon for three sites that differ in the extent of permafrost thaw.
Figure 3: Old carbon loss and its relationship to total ecosystem respiration for three sites that differ in the extent of permafrost thaw.


  1. 1

    Schuur, E. A. G. et al. Vulnerability of permafrost carbon to climate change: Implications for the global carbon cycle. Bioscience 58, 701–714 (2008)

    Article  Google Scholar 

  2. 2

    Zimov, S. A., Schuur, E. A. G. & Chapin, F. S. Permafrost and the global carbon budget. Science 312, 1612–1613 (2006)

    CAS  Article  Google Scholar 

  3. 3

    Field, C. B., Sarmiento, J. & Hales, B. in The First State of the Carbon Cycle Report (SOCCR) — Synthesis and Assessment Product 2.2 (eds King, A.W. et al.) 21–28 (National Oceanic and Atmospheric Administration, National Climatic Data Center, 2007)

    Google Scholar 

  4. 4

    Field, C. B., Lobell, D. B., Peters, H. A. & Chiariello, N. R. Feedbacks of terrestrial ecosystems to climate change. Annu. Rev. Environ. Resour. 32, 1–29 (2007)

    Article  Google Scholar 

  5. 5

    Davidson, E. A. & Janssens, I. A. Temperature sensitivity of soil carbon decomposition and feedbacks to climate change. Nature 440, 165–173 (2006)

    CAS  ADS  Article  Google Scholar 

  6. 6

    Heimann, M. & Reichstein, M. Terrestrial ecosystem carbon dynamics and climate feedbacks. Nature 451, 289–292 (2008)

    CAS  ADS  Article  Google Scholar 

  7. 7

    Oechel, W. C. et al. Recent change of Arctic tundra ecosystems from a net carbon dioxide sink to a source. Nature 361, 520–523 (1993)

    ADS  Article  Google Scholar 

  8. 8

    Harden, J. W., Sundquist, E. T., Stallard, R. F. & Mark, R. K. Dynamics of soil carbon during deglaciation of the Laurentide ice sheet. Science 258, 1921–1924 (1992)

    CAS  ADS  Article  Google Scholar 

  9. 9

    Schirrmeister, L. et al. Paleoenvironmental and paleoclimatic records from permafrost deposits in the Arctic region of Northern Siberia. Quat. Int. 89, 97–118 (2002)

    Article  Google Scholar 

  10. 10

    Zimov, S. A. et al. Permafrost carbon: Stock and decomposability of a globally significant carbon pool. Geophys. Res. Lett. 33 10.1029/2006GL027484 (2006)

  11. 11

    Smith, L. C. et al. Siberian peatlands a net carbon sink and global methane source since the early Holocene. Science 303, 353–356 (2004)

    CAS  ADS  Article  Google Scholar 

  12. 12

    Osterkamp, T. E. Characteristics of the recent warming of permafrost in Alaska. J. Geophys. Res. 112 (F2). 10.1029/2006JF000578 (2007)

  13. 13

    Myneni, R. B., Tucker, C. J., Asrar, G. & Keeling, C. D. Interannual variations in satellite-sensed vegetation index data from 1981 to 1991. J. Geophys. Res. 103 (D6). 6145–6160 (1998)

    ADS  Article  Google Scholar 

  14. 14

    Sturm, M., Racine, C. & Tape, K. Climate change – Increasing shrub abundance in the Arctic. Nature 411, 546–547 (2001)

    CAS  ADS  Article  Google Scholar 

  15. 15

    Chapin, F. S. et al. Role of land-surface changes in Arctic summer warming. Science 310, 657–660 (2005)

    CAS  ADS  Article  Google Scholar 

  16. 16

    Oechel, W. C. et al. Acclimation of ecosystem CO2 exchange in the Alaskan Arctic in response to decadal climate warming. Nature 406, 978–981 (2000)

    CAS  ADS  Article  Google Scholar 

  17. 17

    Vitt, D. H., Halsey, L. A. & Zoltai, S. C. The changing landscape of Canada's western boreal forest: The current dynamics of permafrost. Can. J. For. Res. 30, 283–287 (2000)

    Article  Google Scholar 

  18. 18

    Osterkamp, T. E. The recent warming of permafrost in Alaska. Glob. Planet. Change 49, 187–202 (2005)

    ADS  Article  Google Scholar 

  19. 19

    Osterkamp, T. E. & Romanovsky, V. E. Evidence for warming and thawing of discontinuous permafrost in Alaska. Permafrost Periglac. Process. 10, 17–37 (1999)

    Article  Google Scholar 

  20. 20

    Schuur, E. A. G., Crummer, K. G., Vogel, J. G. & Mack, M. C. Plant species composition and productivity following permafrost thaw and thermokarst in Alaskan tundra. Ecosystems 10, 280–292 (2007)

    Article  Google Scholar 

  21. 21

    Trumbore, S. Age of soil organic matter and soil respiration: Radiocarbon constraints on belowground C dynamics. Ecol. Appl. 10, 399–411 (2000)

    Article  Google Scholar 

  22. 22

    Levin, I. & Hesshaimer, V. Radiocarbon – A unique tracer of global carbon cycle dynamics. Radiocarbon 42, 69–80 (2000)

    CAS  Article  Google Scholar 

  23. 23

    Phillips, D. L. & Gregg, J. W. Source partitioning using stable isotopes: Coping with too many sources. Oecologia 136, 261–269 (2003)

    ADS  Article  Google Scholar 

  24. 24

    Shaver, G. R. et al. Global change and the carbon balance of Arctic ecosystems. Bioscience 42, 433–441 (1992)

    Article  Google Scholar 

  25. 25

    Lawrence, D. M. & Slater, A. G. A projection of severe near-surface permafrost degradation during the 21st century. Geophys. Res. Lett. 32 L24401 10.1029/2005GL025080 (2005)

    ADS  Article  Google Scholar 

  26. 26

    Delisle, G. Near-surface permafrost degradation: How severe during the 21st century? Geophys. Res. Lett. 34 (9) 10.1029/2007GL029323 (2007)

  27. 27

    Mack, M. C. et al. Ecosystem carbon storage in arctic tundra reduced by long-term nutrient fertilization. Nature 431, 440–443 (2004)

    CAS  ADS  Article  Google Scholar 

  28. 28

    Hobbie, S. E. Temperature and plant species control over litter decomposition in Alaskan tundra. Ecol. Monogr. 66, 503–522 (1996)

    Article  Google Scholar 

  29. 29

    Dutta, K., Schuur, E. A. G., Neff, J. C. & Zimov, S. A. Potential carbon release from permafrost soils of Northeastern Siberia. Glob. Change Biol. 12, 2336–2351 (2006)

    ADS  Article  Google Scholar 

  30. 30

    Canadell, J. G. et al. Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks. Proc. Natl Acad. Sci. USA 104, 18866–18870 (2007)

    CAS  ADS  Article  Google Scholar 

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This work was made possible by assistance from G. Adema, T. Chapin, S. DeBiasio, L. Gutierrez, M. Mack, M. Schieber, E. Tissier, C. Trucco, W. Vicars, E. Wilson, C. Wuthrich, L. Yocum, and the researchers and technicians of the Bonanza Creek LTER. This work relied on funds from the following sources: NASA New Investigator Program, NSF Bonanza Creek LTER Program, NSF DEB Ecosystems Program, and a cooperative agreement with the National Park Service.

Author Contributions E.A.G.S. conceived the experiment. E.A.G.S. and J.G.V. designed the experiment and wrote the paper. E.A.G.S., J.G.V., K.G.C. and H.L. performed research. All authors commented on the analysis and presentation of the data and were involved in the writing.

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Correspondence to Edward A. G. Schuur.

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Schuur, E., Vogel, J., Crummer, K. et al. The effect of permafrost thaw on old carbon release and net carbon exchange from tundra. Nature 459, 556–559 (2009).

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