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The charcoal carbon pool in boreal forest soils


Forest fires release significant amounts of carbon dioxide into the atmosphere1, but also convert a fraction of the burning vegetation to charred black carbon. Black carbon is hard to break down, and formation of this reserve therefore creates a long-term soil carbon sink2,3,4,5,6,7. However, although soil black carbon pools are important for global carbon budgets, the spatial variation and dynamics of these pools are poorly understood6,7,8,9. Here we examine the charcoal content of 845 soil samples collected from a broad range of boreal forest landscapes and climates in Scandinavia. We show that there is considerable variation in the distribution and carbon content of soil charcoal between forest landscapes; the landscape-level amount of soil carbon stored in charcoal ranged from 0 to 222 g C m−2, with an average of 77 g C m−2. The carbon concentration in the soil charcoal is significantly lower than that found in recently produced fresh charcoal, suggesting that charcoal carbon content decreases with time. Indeed, the median age of a subset of 14C-dated soil charcoal particles was 652 years, implying a rapid turnover compared with the expected median age of approximately 5,000 years if charcoal is persistent. Assuming that our measurements are representative of boreal forests worldwide, we estimate that boreal forest soils store 1 Pg of carbon in the form of charcoal, equivalent to 1% of the total plant carbon stock in boreal forests.

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Figure 1: Geographic distribution of study sites and appearance of charcoal in boreal forest soils.
Figure 2: Concentration of carbon in different types of charcoal.
Figure 3: Charcoal and its content of carbon in boreal forest soils.


  1. IPCC Climate Change 2007: The Physical Science Basis (eds Solomon, S. et al.) (Cambridge Univ. Press, 2007).

  2. Goldberg, E. D. Black Carbon in the Environment: Properties and Distribution (Wiley, 1985).

    Google Scholar 

  3. Skjemstad, J. O., Clarke, P., Taylor, J. A., Oades, J. M. & McClure, S. G. The chemistry and nature of protected carbon in soil. Aust. J. Soil Res. 34, 251–271 (1996).

    Article  Google Scholar 

  4. Schmidt, M. W. I. & Noack, A. G. Black carbon in soils and sediments: Analysis, distribution, implications, and current challenges. Glob. Biogeochem. Cycles 14, 777–793 (2000).

    Article  Google Scholar 

  5. Czimczik, C. I., Preston, C. M., Schmidt, M. W. I. & Schulze, E. D. How surface fire in Siberian Scots pine forests affects soil organic carbon in the forest floor: Stocks, molecular structure, and conversion to black carbon (charcoal). Glob. Biogeochem. Cycles 17, 1020 (2003).

    Article  Google Scholar 

  6. Preston, C. M. & Schmidt, M. W. I. Black (pyrogenic) carbon: A synthesis of current knowledge and uncertainties with special consideration of boreal regions. Biogeosciences 3, 397–420 (2006).

    Article  Google Scholar 

  7. Lehmann, J. et al. Australian climate–carbon cycle feedback reduced by soil black carbon. Nature Geosci. 1, 832–835 (2008).

    Article  Google Scholar 

  8. Schmidt, M. W. I. Carbon budget in the black. Nature 427, 305–307 (2004).

    Article  Google Scholar 

  9. Forbes, M. S., Raison, R. J. & Skjemstad, J. O. Formation, transformation and transport of black carbon. Sci. Total Environ. 370, 190–206 (2006).

    Article  Google Scholar 

  10. Marlon, J. R. et al. Climate and human influences on global biomass burning over the past two millennia. Nature Geosci. 1, 697–702 (2008).

    Article  Google Scholar 

  11. Bonan, G. B. & Shugart, H. H. Environmental factors and ecological processes in boreal forests. Annu. Rev. Ecol. Syst. 20, 1–28 (1989).

    Article  Google Scholar 

  12. Czimczik, C. I., Schmidt, M. W. I. & Schulze, E. D. Effects of increasing fire frequency on black carbon and organic matter in Podzols of Siberian Scots pine forests. Eur. J. Soil Sci. 56, 417–428 (2005).

    Article  Google Scholar 

  13. Ohlson, M. & Tryterud, E. Long-term spruce forest continuity—a challenge for a sustainable Scandinavian forestry. For. Ecol. Manage. 124, 27–34 (1999).

    Article  Google Scholar 

  14. Randerson, J. T. et al. The impact of boreal forest fire on climate warming. Science 314, 1130–1132 (2006).

    Article  Google Scholar 

  15. Stocks, B. J. Forest fires in the boreal zone: Climate change and carbon implications. IFFN 31, 122–131 (2004).

    Google Scholar 

  16. Balshi, M. S. et al. Vulnerability of carbon storage in North American boreal forests to wildfire during the 21st century. Glob. Change Biol. 15, 1491–1510 (2009).

    Article  Google Scholar 

  17. Girardin, M. P. et al. Heterogeneous response to circumpolar wildfire risk to climate change since early 1900s. Glob. Change Biol. 15, 10.1111/j.1365-2486.2009.01869.x (2009).

  18. Schmidt, M. W. I. et al. Comparative analysis of black carbon in soils. Glob. Biogeochem. Cycles 15, 163–167 (2001).

    Article  Google Scholar 

  19. Ohlson, M. & Tryterud, E. Interpretation of the charcoal record in forest soils: Forest fires and their production and deposition of macroscopic charcoal. Holocene 10, 519–525 (2000).

    Article  Google Scholar 

  20. Dickens, A. F., Gélinas, Y., Masiello, C. A., Wakeham, S. & Hedges, J. I. Reburial of fossil organic carbon in marine sediments. Nature 427, 336–339 (2004).

    Article  Google Scholar 

  21. Quénéa, K. et al. Black carbon yields and types in forest and cultivated sandy soils (Landes de Gascogne, France) as determined with different methods: Influence of change in land use. Org. Geochem. 37, 1185–1189 (2006).

    Article  Google Scholar 

  22. Akselsson, C., Berg, B., Meentemeyer, V. & Westling, O. Carbon sequestration rates in organic layers of boreal and temperate forest soils—Sweden a case study. Glob. Ecol. Biogeogr. 14, 77–84 (2005).

    Article  Google Scholar 

  23. Pietikäinen, J., Kiikkilä, O. & Fritze, H. Charcoal as a habitat for microbes and its effect on the microbial community of the underlying humus. Oikos 89, 231–242 (2000).

    Article  Google Scholar 

  24. Bradshaw, R. H. W., Tolonen, K. & Tolonen, M. in Sediment Records and Biomass Burning and Global Change (eds Clark, J. S., Cachier, H., Goldammer, J. G. & Stocks, B.) 169–188 (Springer, 1997).

    Google Scholar 

  25. Hammes, K., Tom, M. S., Lapenas, A. G. & Schmidt, M. W. I. Centennial black carbon turnover observed in a Russian steppe soil. Biogeosciences 5, 1339–1350 (2008).

    Article  Google Scholar 

  26. Zackrisson, O., Nilsson, M.- C. & Wardle, D. A. Key ecological function of charcoal from wildfire in the Boreal forest. Oikos 77, 10–19 (1996).

    Article  Google Scholar 

  27. Davidson, E. A., Trumbore, S. E. & Amundson, R. Soil warming and organic carbon content. Nature 408, 789–790 (2000).

    Article  Google Scholar 

  28. Knorr, W., Prentice, I. C., House, J. I. & Holland, E. A. Long-term sensitivity of soil carbon turnover to warming. Nature 433, 298–301 (2005).

    Article  Google Scholar 

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This research was financially supported by grants from the Research Council of Norway. We thank T. W. Swetnam for comments and J. G. Dokk, M. Haugmo, E. J. Kristoffersen, O. W. Røstad, E. Tryterud and A. N. Wist for technical assistance.

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T.Ø. and R.H. designed the approach for the spatial positioning of the soil samples and selected all sampling positions except those in sites E, L, M and O, which were selected by M.O. B.D. measured macroscopic charcoal. K.J.B. analysed the microscopic charcoal fraction. R.H. and M.O. analysed the data. M.O. wrote the paper. All authors discussed and edited the manuscript.

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Correspondence to Mikael Ohlson.

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Ohlson, M., Dahlberg, B., Økland, T. et al. The charcoal carbon pool in boreal forest soils. Nature Geosci 2, 692–695 (2009).

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