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Arctic microorganisms respond more to elevated UV-B radiation than CO2

Abstract

Surface ultraviolet-B radiation and atmospheric CO2 concentrations have increased as a result of ozone depletion and burning of fossil fuels1,2. The effects are likely to be most apparent in polar regions3 where ozone holes have developed and ecosystems are particularly sensitive to disturbance4. Polar plant communities are dependent on nutrient cycling by soil microorganisms, which represent a significant and highly labile portion of soil carbon (C) and nitrogen (N). It was thought5 that the soil microbial biomass was unlikely to be affected by exposure of their associated plant communities to increased UV-B. In contrast, increasing atmospheric CO2 concentrations were thought to have a strong effect as a result of greater below-ground C allocation6. In addition, there is a growing belief that ozone depletion is of only minor environmental concern because the impacts of UV-B radiation on plant communities are often very subtle7. Here we show that 5 years of exposure of a subarctic heath to enhanced UV-B radiation both alone and in combination with elevated CO2 resulted in significant changes in the C:N ratio and in the bacterial community structure of the soil microbial biomass.

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References

  1. Müller, R. et al. Severe chemical ozone loss in the Arctic during the winter of 1995–96. Nature 398, 709–712 (1997).

    Article  ADS  Google Scholar 

  2. Houghton, J. T. et al. (eds) Climate Change 1995: The Science of Climate Change (Cambridge Univ. Press, Cambridge, 1996).

    Google Scholar 

  3. Caldwell, M. M., Robberecht, R. & Nowak, R. S. Differential photosynthetic inhibition by ultraviolet-B radiation in species from the arctic-alpine lifezone. Arct. Alp. Res. 14, 195–202 (1982).

    Article  Google Scholar 

  4. Callaghan, T. V. & Jonasson, S. Arctic terrestrial ecosystems and environmental change. Phil. Trans. R. Soc. Lond. A 352, 259–276 (1995).

    Article  ADS  Google Scholar 

  5. Moorhead, D. L. & Callaghan, T. V. Effects of increasing ultraviolet-B radiation on decomposition and soil organic matter dynamics: a synthesis and modelling study. Biol. Fertil. Soils 19, 19–26 (1994).

    Article  Google Scholar 

  6. Hungate, B. A. et al. The fate of carbon in grasslands under carbon dioxide enrichment. Nature 388, 576–579 (1997).

    Article  ADS  CAS  Google Scholar 

  7. Caldwell, M. M., Searles, P. S., Flint, S. D. & Barnes, P. W. in Physiological Plant Ecology (eds Press, M. C., Scholes, J. D. & Barker, M. G.) 241–262 (Blackwell, Oxford, 1999).

    Google Scholar 

  8. Vance, E. D., Brookes, P. C. & Jenkinson, D. S. An extraction method for measuring microbial biomass-C. Soil Biol. Biochem. 19, 703–707 (1987).

    Article  CAS  Google Scholar 

  9. Brookes, P. C., Landman, A., Pruden, G. & Jenkinson, D. S. Chloroform fumigation and the release of soil-nitrogen—a rapid direct extraction method to measure microbial biomass nitrogen in soil. Soil Biol. Biochem. 17, 837–842 (1985).

    Article  CAS  Google Scholar 

  10. Campbell, C. D., Grayston, S. J. & Hirst, D. J. Use of rhizosphere carbon sources in sole carbon source tests to discriminate soil microbial communities. J. Microbiol. Methods 30, 33–41 (1997).

    Article  Google Scholar 

  11. Ellenberg, H. Vegetation Ecology of Central Europe. 4th edn (Cambridge Univ. Press, Cambridge, 1988).

    Google Scholar 

  12. Schlesinger, W. H. & Lichter, J. Limited storage in soil and litter of experimental forest plots under increased atmospheric CO2. Nature 411, 466–469 (2001).

    Article  ADS  CAS  Google Scholar 

  13. Oren, R. et al. Soil fertility limits carbon sequestration by forest ecosystems in a CO2-enriched atmosphere. Nature 411, 469–472 (2001).

    Article  ADS  CAS  Google Scholar 

  14. Johanson, U., Gehrke, C., Bjorn, L. O., Callaghan, T. V. & Sonesson, M. The effects of enhanced UV-B radiation on a subarctic heath ecosystem. Ambio 24, 106–111 (1995).

    Google Scholar 

  15. Sonesson, M. & Lundberg, B. Late quaternary forest development of the Torneträsk area, North Sweden. 1. Structure of modern forest ecosystems. Oikos 25, 121–133 (1974).

    Article  Google Scholar 

  16. Björn, L. O. & Holmgren, B. Monitoring and modelling of the radiation climate at Abisko. Ecol. Bull. 45, 204–209 (1996).

    Google Scholar 

  17. Gwynn-Jones, D., Lee, J. A. & Callaghan, T. V. Effects of enhanced UV-B radiation and elevated carbon dioxide concentrations on a sub-arctic forest heath ecosystem. Plant Ecol. 128, 242–249 (1997).

    Article  Google Scholar 

  18. Bremner, J. M. & Mulvaney, C. S. in Agronomy 9: Methods of Soil Analyses. Part 2. Chemical and Microbiological Properties (eds Page, A. C., Miller, R. H. & Keeney, D. R.) 595–624 (Soil Science Soc. America, Madison, 1982).

    Google Scholar 

  19. Scheiner, D. Determination of ammonia and Kjeldahl nitrogen by indophenol method. Water Res. 10, 31–36 (1976).

    Article  CAS  Google Scholar 

  20. Garland, J. L. & Mills, A. L. Classification and characterisation of heterotrophic microbial communities on the basis of patterns of community-level sole carbon-source utilisation. Appl. Environ. Microbiol. 57, 2351–2359 (1991).

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank D. Mackinnon for TOC analysis and S. J. Chapman, L. A. Gilbert and J. R. Leake for their comments. This work was supported by the Natural Environment Research Council, the European Union and the Swedish Academy of Sciences. C.D.C. is funded by the Scottish Executive, Environment and Rural Affairs Department.

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Correspondence to David Johnson.

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Johnson, D., Campbell, C., Lee, J. et al. Arctic microorganisms respond more to elevated UV-B radiation than CO2. Nature 416, 82–83 (2002). https://doi.org/10.1038/416082a

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