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AMBIO

, Volume 41, Supplement 3, pp 218–230 | Cite as

Two Decades of Experimental Manipulations of Heaths and Forest Understory in the Subarctic

  • Anders Michelsen
  • Riikka Rinnan
  • Sven Jonasson
Article

Abstract

Current atmospheric warming due to increase of greenhouse gases will have severe consequences for the structure and functioning of arctic ecosystems with changes that, in turn, may feed back on the global-scale composition of the atmosphere. During more than two decades, environmental controls on biological and biogeochemical processes and possible atmospheric feedbacks have been intensely investigated at Abisko, Sweden, by long-term ecosystem manipulations. The research has addressed questions like environmental regulation of plant and microbial community structure and biomass, carbon and nutrient pools and element cycling, including exchange of greenhouse gases and volatile organic compounds, with focus on fundamental processes in the interface between plants, soil and root-associated and free-living soil microorganisms. The ultimate goal has been to infer from these multi-decadal experiments how subarctic and arctic ecosystems will respond to likely environmental changes in the future. Here we give an overview of some of the experiments and main results.

Keywords

Tundra Warming Field experiments Plant–microbe interactions Carbon and nitrogen cycling 

Notes

Acknowledgments

We are grateful to the staff at the Abisko Scientific Research Station for excellent facilities and support, and to the Director through many years, Prof. Terry V. Callaghan, for his encouragement and enthusiastic work in arctic ecological research. The studies have been supported by multiple grants from The Danish Council for Independent Research. We also wish to thank The Danish National Research Foundation for funding the activities within the Center for Permafrost (CENPERM). Numerous colleagues, students and field assistants are thanked for enthusiastic collaboration during the field and analytical work.

References

  1. Aerts, R. 2006. The freezer defrosting: Global warming and litter decomposition rates in cold biomes. Journal of Ecology 94: 713–724.CrossRefGoogle Scholar
  2. Aerts, R., J.H.C. Cornelissen, and E. Dorrepaal. 2006. Plant performance in a warmer world: General responses of plants from cold, northern biomes and the importance of winter and spring events. Plant Ecology 182: 65–77.Google Scholar
  3. Andresen, L.C., A. Michelsen, L. Ström, and S. Jonasson. 2008. Uptake of pulse injected nitrogen by soil microbes and mycorrhizal and non-mycorrhizal plants in a species-diverse subarctic heath ecosystem. Plant and Soil 313: 283–295. doi: 10.1007/s11104-008-9700-7.CrossRefGoogle Scholar
  4. Arroniz-Crespo, M., M.D. Gwynn-Jones, T.V. Callaghan, E. Nunez-Olivera, J. Martınez-Abaigar, P. Horton, and G.K. Phoenix. 2011. Impacts of long-term enhanced UV-B radiation on bryophytes in two sub-Arctic heathland sites of contrasting water availability. Annals of Botany 108: 557–565.CrossRefGoogle Scholar
  5. Bjerke, J.W., S. Bokhorst, M. Zielke, T.V. Callaghan, F.C. Bowles, and G.K. Phoenix. 2011. Contrasting sensitivity to extreme winter warming events of dominant sub-Arctic heathland bryophyte and lichen species. Journal of Ecology 99: 1481–1488.CrossRefGoogle Scholar
  6. Björk, R.G., H. Majdi, L. Klemedtsson, L. Lewis-Jonsson, and U. Molau. 2007. Long-term warming effects on root morphology, root mass distribution, and microbial activity in two dry tundra plant communities in northern Sweden. New Phytologist 176: 862–873.CrossRefGoogle Scholar
  7. Bokhorst, S., J.W. Bjerke, L.E. Street, T.V. Callaghan, and G.K. Phoenix. 2011. Impacts of multiple extreme winter warming events on sub-Arctic heathland: Phenology, reproduction, growth, and CO2 flux responses. Global Change Biology 17: 2817–2830.CrossRefGoogle Scholar
  8. Callaghan, T.V., L.O. Björn, Y. Chernov, T. Chapin, T.R. Christensen, B. Huntley, R.A. Ims, M. Johansson, et al. 2004. Effects on the function of Arctic ecosystems in the short- and long-term perspectives. AMBIO 33: 448–458.Google Scholar
  9. Christensen, T.R., T. Johansson, M. Olsrud, L. Ström, A. Lindroth, M. Mastepanov, N. Malmer, T. Friborg, et al. 2007. A catchment-scale carbon and greenhouse gas budget of a subarctic landscape. Philosophical Transactions of the Royal Society A-Mathematical Physical and Engineering Sciences 365: 1643–1656.CrossRefGoogle Scholar
  10. Christensen, T.R., A. Michelsen, and S. Jonasson. 1999. Exchange of CH4 and N2O in a subarctic heath soil: Effects of inorganic N and P and amino acid addition. Soil Biology & Biochemistry 31: 637–641.CrossRefGoogle Scholar
  11. Christensen, T.R., A. Michelsen, S. Jonasson, and I.K. Schmidt. 1997. Carbon dioxide and methane exchange of a subarctic heath in response to climate change related environmental manipulations. Oikos 79: 34–44.CrossRefGoogle Scholar
  12. Clemmensen, K.E., and A. Michelsen. 2006. Integrated long-term responses of an arctic-alpine willow and associated ectomycorrhizal fungi to an altered environment. Canadian Journal of Botany 84: 831–843.CrossRefGoogle Scholar
  13. Clemmensen, K.E., A. Michelsen, S. Jonasson, and G.R. Shaver. 2006. Increased ectomycorrhizal fungal abundance after long-term fertilization and warming of two arctic tundra ecosystems. New Phytologist 171: 391–404.CrossRefGoogle Scholar
  14. Clemmensen, K.E., P.L. Sørensen, A. Michelsen, S. Jonasson, and L. Ström. 2008. Site-dependent N uptake from N-form mixtures by arctic plants, soil microbes and ectomycorrhizal fungi. Oecologia 155: 771–783. doi: 10.1007/s00442-008-0962-9.CrossRefGoogle Scholar
  15. Craine, J.M., A.J. Elmore, M.P.M. Aidar, M. Bustamante, T.E. Dawson, E.A. Hobbie, A. Kahmen, M.C. Mack, et al. 2009. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytologist 183: 980–992. doi: 10.1111/j.1469-8137.2009.02917.x.CrossRefGoogle Scholar
  16. Dorrepaal, E., S. Toet, R.S.P. van Logtestijn, E. Swart, M.J. van de Weg, T.V. Callaghan, and R. Aerts. 2009. Carbon respiration from subsurface peat accelerated by climate warming in the subarctic. Nature 460: 616–619.CrossRefGoogle Scholar
  17. Ekberg, A., A. Arneth, H. Hakola, S. Hayward, and T. Holst. 2009. Isoprene emission from wetland sedges. Biogeosciences 6: 601–613.CrossRefGoogle Scholar
  18. Ekberg, A., A. Arneth, and T. Holst. 2011. Isoprene emission from Sphagnum species occupying different growth positions above the water table. Boreal Environment Research 16: 47–59.Google Scholar
  19. Elmendorf, S., G. Henry, R. Hollister, R. Björk, A. Bjorkman, T.V. Callaghan, L. Collier, E. Cooper, et al. 2012. Global assessment of experimental climate warming on tundra vegetation: Heterogeneity over space and time. Ecology Letters 15: 164–175.CrossRefGoogle Scholar
  20. Fahnestock, J.T., M.H. Jones, and J.M. Welker. 1999. Wintertime CO2 efflux from Arctic soils: Implications for annual carbon budgets. Global Biogeochemical Cycles 13: 775–779.CrossRefGoogle Scholar
  21. Faubert, P., P. Tiiva., A. Michelsen, Å. Rinnan, H. Ro-Poulsen, and R. Rinnan. 2012. The shift in plant species composition in a subarctic mountain birch forest floor due to climate change would modify the biogenic volatile organic compound emission profile. Plant and Soil 352: 199–215. doi: 10.1007/s11104-011-0989-2.
  22. Faubert, P., P. Tiiva, Å. Rinnan, A. Michelsen, J.K. Holopainen, and R. Rinnan. 2010. Doubled volatile organic compound emissions from subarctic tundra under simulated climate warming. New Phytologist 187: 199–208. doi: 10.1111/j.1469-8137.2010.03270.x.CrossRefGoogle Scholar
  23. Fox, A.M., B. Huntley, C.R. Lloyd, M. Williams, and R. Baxter. 2008. Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements. Global Biogeochemical Cycles 22: GB2027.CrossRefGoogle Scholar
  24. Graglia, E., S. Jonasson, A. Michelsen, I.K. Schmidt, M. Havström, and L. Gustavsson. 2001. Effects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatments. Ecography 24: 5–12.CrossRefGoogle Scholar
  25. Grogan, P., L. Illeris, A. Michelsen, and S. Jonasson. 2001. Respiration of recently-fixed plant carbon dominates mid-winter ecosystem CO2 production in sub-arctic heath tundra. Climatic Change 50: 129–142.CrossRefGoogle Scholar
  26. Grogan, P., and S. Jonasson. 2003. Controls on annual nitrogen cycling in the understory of a subarctic birch forest. Ecology 84: 202–218.CrossRefGoogle Scholar
  27. Haapanala, S., A. Ekberg, H. Hakola, V. Tarvainen, J. Rinne, H. Hellen, and A. Arneth. 2009. Mountain birch—potentially large source of sesquiterpenes into high latitude atmosphere. Biogeosciences 6: 2709–2718.CrossRefGoogle Scholar
  28. Hansen, A.H., S. Jonasson, A. Michelsen, and R. Julkunen-Tiitto. 2006. Long-term experimental warming, shading and nutrient addition affect the concentration of phenolic compounds in subarctic deciduous and evergreen dwarf shrubs. Oecologia 147: 1–11.CrossRefGoogle Scholar
  29. Hartley, A.E., C. Neill, J.M. Melillo, R. Crabtree, and F.P. Bowles. 1999. Plant performance and soil nitrogen mineralization in response to simulated climate change in subarctic dwarf shrub heath. Oikos 86: 331–343.CrossRefGoogle Scholar
  30. Haugwitz, M.S., and A. Michelsen. 2011. Long-term addition of fertilizer, labile carbon and fungicide alters the biomass of plant functional groups in a subarctic-alpine community. Plant Ecology 212: 715–726. doi: 10.1007/s11258-010-9857-z.CrossRefGoogle Scholar
  31. Haugwitz, M.S., I.K. Schmidt, and A. Michelsen. 2011. Long-term microbial control of nutrient availability and plant biomass in a subarctic-alpine heath after addition of carbon, fertilizer and fungicide. Soil Biology & Biochemistry 43: 179–187. doi: 10.1016/j.soilbio.2010.09.032.CrossRefGoogle Scholar
  32. Holst, T., A. Arneth, S. Hayward, A. Ekberg, M. Mastepanov, M. Jackowicz-Korczynski, T. Friborg, P.M. Crill, and K. Bäckstrand. 2010. BVOC ecosystem flux measurements at a high latitude wetland site. Atmospheric Chemistry and Physics 10: 1617–1634.CrossRefGoogle Scholar
  33. Illeris, L., S.M. König, P. Grogan, S. Jonasson, A. Michelsen, and H. Ro-Poulsen. 2004. Growing season carbon dioxide flux in a dry subarctic heath: Responses to long-term manipulations. Arctic, Antarctic, and Alpine Research 36: 456–463.CrossRefGoogle Scholar
  34. Jonasson, S., J. Castro, and A. Michelsen. 2006. Interactions between plants, litter and microbes in cycling of nitrogen and phosphorus in the arctic. Soil Biology & Biochemistry 38: 526–532.CrossRefGoogle Scholar
  35. Jonasson, S., and A. Michelsen. 1996. Plant nutrition and nutrient cycling in the Subarctic, with special reference to the Abisko and Torneträsk area. Ecological Bulletins 45: 45–52.Google Scholar
  36. Jonasson, S., A. Michelsen, I.K. Schmidt, and E.V. Nielsen. 1999. Responses in microbes and plants to changed temperature, nutrient, and light regimes in the Arctic. Ecology 80: 1828–1843.CrossRefGoogle Scholar
  37. Karlsson G.P., C. Akselsson, S. Hellsten, P.E. Karlsson, and G. Malm. 2009. Övervakning av luftföroreningar norra Sverige – mätningar och moddellering. Svenska Miljöinstitut IVL rapport B1851. Lund Universitet (in Swedish).Google Scholar
  38. Kjøller, R., M. Olsrud, and A. Michelsen. 2010. Co-existing ericaceous plant species in a subarctic heath community share fungal root endophytes. Fungal Ecology 3: 205–214.CrossRefGoogle Scholar
  39. Konestabo, S.H., A. Michelsen, and M. Holmstrup. 2007. Responses of springtail and mite populations to prolonged periods of soil freeze–thaw cycles in a sub-arctic ecosystem. Applied Soil Ecology 36: 136–146. doi: 10.1016/j.apsoil.2007.01.003.CrossRefGoogle Scholar
  40. Krab, E.J., J.H.C. Cornelissen, S.I. Lang, and R.S.P. van Logtestijn. 2008. Amino acid uptake among wide-ranging moss species may contribute to their strong position in higher-latitude ecosystems. Plant and Soil 304: 199–208.CrossRefGoogle Scholar
  41. Kullman, L., and L. Öberg. 2009. Post-Little Ice Age tree line rise and climate warming in the Swedish Scandes: A landscape ecological perspective. Journal of Ecology 97: 415–429.CrossRefGoogle Scholar
  42. Larsen, K.S., P. Grogan, S. Jonasson, and A. Michelsen. 2007a. Respiration and microbial dynamics in two sub-arctic ecosystems during winter and spring thaw: Effects of increased snow depth. Arctic, Antarctic, and Alpine Research 39: 268–276.CrossRefGoogle Scholar
  43. Larsen, K.S., A. Ibrom, S. Jonasson, A. Michelsen, and C. Beier. 2007b. Significance of cold-season respiration and photosynthesis in a subarctic heath ecosystem in Northern Sweden. Global Change Biology 13: 1498–1508. doi: 10.1111/j.1365-2486.2007.01370.x.CrossRefGoogle Scholar
  44. Mack, M.C., E.A.G. Schuur, M.S. Bret-Harte, G.R. Shaver, and F.S. Chapin III. 2004. Ecosystem carbon storage in arctic tundra reduced by long-term nutrient fertilization. Nature 431: 440–443.CrossRefGoogle Scholar
  45. McKane, R.B., L.C. Johnson., G.R. Shaver, K.J. Nadelhoffer, E.B. Rastetter, B. Fry, A.E. Giblin, K. Kielland, et al. 2002. Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra. Nature 415: 68–71.CrossRefGoogle Scholar
  46. Michelsen, A., E. Graglia, I.K. Schmidt, S. Jonasson, C. Quarmby, and D. Sleep. 1999. Differential responses of grass and a dwarf shrub to long-term changes in soil microbial biomass C, N and P by factorial NPK fertilizer, fungicide and labile carbon addition to a heath. New Phytologist 143: 523–538.CrossRefGoogle Scholar
  47. Michelsen, A., S. Jonasson, D. Sleep, M. Havström, and T.V. Callaghan. 1996. Shoot biomass, δ13C, nitrogen and chlorophyll responses of two arctic dwarf-shrubs to in situ shading, nutrient application and warming simulating climatic change. Oecologia 105: 1–12.CrossRefGoogle Scholar
  48. Michelsen, A., C. Quarmby, D. Sleep, and S. Jonasson. 1998. Vascular plant 15N natural abundance in heath and forest tundra ecosystems is closely correlated with presence and type of mycorrhizal fungi in roots. Oecologia 115: 406–418.CrossRefGoogle Scholar
  49. Molau, U. 2010. Long-term impacts of observed and induced climate change on tussock tundra near its southern limit in northern Sweden. Plant Ecology and Diversity 3: 29–34.CrossRefGoogle Scholar
  50. Olsrud, M., B.Å. Carlsson, B.M. Svensson, A. Michelsen, and J.M. Melillo. 2010. Responses of fungal root colonization, plant cover and leaf nutrients to long-term exposure to elevated atmospheric CO2 and warming in a subarctic birch forest understory. Global Change Biology 16: 1820–1829. doi: 10.1111/j.1365-2486.2009.02079.x.CrossRefGoogle Scholar
  51. Olsrud, M., and A. Michelsen. 2009. Effects of shading on photosynthesis, plant organic nitrogen uptake and root fungal colonization in a subarctic mire ecosystem. Botany 87: 463–474. doi: 10.1139/B09-021.CrossRefGoogle Scholar
  52. Olsrud, M., A. Michelsen, and H. Wallander. 2007. Ergosterol content in ericaceous hair roots correlates with dark septate endophytes but not with ericoid mycorrhizal colonization. Soil Biology & Biochemistry 39: 1218–1221. doi: 10.1016/j.soilbio.2006.11.018.CrossRefGoogle Scholar
  53. Peñuelas, K., and M. Staudt. 2010. BVOCs and global change. Trends in Plant Science 15: 133–144.CrossRefGoogle Scholar
  54. Press, M.C., J.A. Potter, M.J.W. Burke, T.V. Callaghan, and J.A. Lee. 1998. Responses of a subarctic dwarf shrub heath community to simulated environmental change. Journal of Ecology 86: 315–327.CrossRefGoogle Scholar
  55. Rinnan, R., A. Michelsen, and E. Bååth. 2011a. Long-term warming of a subarctic heath decreases soil bacterial community growth but has no effects on its temperature adaptation. Applied Soil Ecology 47: 217–220. doi: 10.1016/j.apsoil.2010.12.011.CrossRefGoogle Scholar
  56. Rinnan, R., A. Michelsen, E. Bååth, and S. Jonasson. 2007a. Fifteen years of climate change manipulations alter soil microbial communities in a subarctic heath ecosystem. Global Change Biology 13: 28–39. doi: 10.1111/j.1365-2486.2006.01263.x.CrossRefGoogle Scholar
  57. Rinnan, R., A. Michelsen, E. Bååth, and S. Jonasson. 2007b. Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter. Soil Biology & Biochemistry 39: 3014–3023.CrossRefGoogle Scholar
  58. Rinnan, R., A. Michelsen, and S. Jonasson. 2008. Effects of litter addition and warming on soil carbon, nutrient pools and microbial communities in a subarctic heath ecosystem. Applied Soil Ecology 39: 271–281. doi: 10.1016/j.apsoil.2007.12.014.CrossRefGoogle Scholar
  59. Rinnan, R., Å. Rinnan, P. Faubert, P. Tiiva, J.K. Holopainen, and A. Michelsen. 2011b. Few long-term effects of simulated climate change on volatile organic compound emissions and leaf chemistry of three subarctic dwarf shrubs. Environmental and Experimental Botany 72: 377–386.CrossRefGoogle Scholar
  60. Robinson, C.H., P.A. Wookey, A.N. Parsons, J.A. Potter, T.V. Callaghan, J.A. Lee, M.C. Press, and J.M. Welker. 1995. Responses of plant litter decomposition and nitrogen mineralisation to simulated environmental change in a high arctic polar semi-desert and a subarctic dwarf shrub heath. Oikos 74: 503–512.CrossRefGoogle Scholar
  61. Ruess, L., A. Michelsen, I.K. Schmidt, and S. Jonasson. 1999. Simulated climate change affecting microorganisms, nematode density and biodiversity in subarctic soils. Plant and Soil 212: 63–73.CrossRefGoogle Scholar
  62. Rundqvist, S., H. Hedenås, A. Sandström, U. Emanuelsson, H. Eriksson, C. Jonasson, and T.V. Callaghan. 2011. Tree and shrub expansion over the past 34 years at the tree-line near Abisko, Sweden. AMBIO 40: 683–692.CrossRefGoogle Scholar
  63. Schmidt, I.K., S. Jonasson, G.R. Shaver, A. Michelsen, and A. Nordin. 2002. Mineralization and distribution of nutrients in plants and microbes in four arctic ecosystems: Responses to warming. Plant and Soil 242: 93–106.CrossRefGoogle Scholar
  64. Sjögersten, S., and P.A. Wookey. 2009. The impact of climate change on ecosystem carbon dynamics at the Scandinavian mountain birch forest–tundra heath ecotone. AMBIO 38: 2–10.CrossRefGoogle Scholar
  65. Sjursen, H., A. Michelsen, and S. Jonasson. 2005. Effects of long-term soil warming and fertilisation on microarthropod abundances in three sub-arctic ecosystems. Applied Soil Ecology 30: 148–161.CrossRefGoogle Scholar
  66. Solheim, B., U. Johanson, T.V. Callaghan, J.A. Lee, D. Gwynn-Jones, and L.O. Björn. 2002. The nitrogen fixation potential of arctic cryptogram species is influenced by enhanced UV-B radiation. Oecologia 133: 90–93.CrossRefGoogle Scholar
  67. Sorensen, P.L., S. Lett, and A. Michelsen. 2012. Moss specific changes in nitrogen fixation following two decades of warming, shading and fertilizer addition. Plant Ecology 213: 695–706. doi: 10.1007/s11258-012-0034-4.CrossRefGoogle Scholar
  68. Sorensen, P.L., and A. Michelsen. 2011. Long-term warming and litter addition affects nitrogen fixation in subarctic heath. Global Change Biology 17: 528–537. doi: 10.1111/j.1365-2486.2010.02234.x/pdf.CrossRefGoogle Scholar
  69. Sorensen, P.L., A. Michelsen, and S. Jonasson. 2006. Nitrogen fixation, denitrification and ecosystem nitrogen pools in relation to vegetation development in the Subarctic. Arctic, Antarctic, and Alpine Research 38: 263–272.CrossRefGoogle Scholar
  70. Sorensen, P.L., A. Michelsen, and S. Jonasson. 2008a. Ecosystem partitioning of 15N-glycine after long-term climate manipulations, plant clipping and addition of labile carbon in a subarctic heath tundra. Soil Biology & Biochemistry 40: 2344–2350. doi: 10.1016/j.soilbio.2008.05.013.CrossRefGoogle Scholar
  71. Sorensen, P.L., A. Michelsen, and S. Jonasson. 2008b. Nitrogen uptake during one year in subarctic plant functional groups and in microbes after long-term warming and fertilization. Ecosystems 11: 223–233. doi: 10.1007/s10021-008-9204-6.CrossRefGoogle Scholar
  72. Tiiva, P., P. Faubert, A. Michelsen, T. Holopainen, J.K. Holopainen, and R. Rinnan. 2008. Climatic warming increases isoprene emission from a subarctic heath. New Phytologist 180: 853–863. doi: 10.1111/j.1469-8137.2008.02587.x.CrossRefGoogle Scholar
  73. Urcelay, C., M.S. Bret-Harte, S. Diaz, and F.S. Chapin III. 2003. Mycorrhizal colonization mediated by species interactions in arctic tundra. Oecologia 137: 399–404.CrossRefGoogle Scholar
  74. van Wijk, M.T., K.E. Clemmensen, G.R. Shaver, M. Williams, T.V. Callaghan, F.S. Chapin III, J.H.C. Cornelissen, L. Gough, et al. 2004. Long-term ecosystem level experiments at Toolik Lake, Alaska, and at Abisko, Northern Sweden: Generalisations and differences in ecosystem and plant type responses to global change. Global Change Biology 10: 105–123.CrossRefGoogle Scholar
  75. Welker, J.M., J.T. Fahnestock, G.H.R. Henry, K.W. O’Dea, and R.A. Chimner. 2004. CO2 exchange in three Canadian High Arctic ecosystems: Response to long-term experimental warming. Global Change Biology 10: 1981–1995.CrossRefGoogle Scholar
  76. Welker, J.M., J.T. Fahnestock, and M.H. Jones. 2000. Annual CO2 flux in dry and moist arctic tundra: Field responses to increases in summer temperatures and winter snow depth. Climatic Change 44: 139–150.CrossRefGoogle Scholar
  77. Yano, Y., G.R. Shaver, A.E. Giblin, and E.B. Rastetter. 2010. Depleted 15N in hydrolysable-N of arctic soils and its implication for mycorrhizal fungi–plant interaction. Biogeochemistry 97: 183–194.CrossRefGoogle Scholar

Copyright information

© Royal Swedish Academy of Sciences 2012

Authors and Affiliations

  • Anders Michelsen
    • 1
    • 2
  • Riikka Rinnan
    • 1
    • 2
  • Sven Jonasson
    • 1
  1. 1.Terrestrial Ecology Section, Department of BiologyUniversity of CopenhagenCopenhagen ØDenmark
  2. 2.Center for Permafrost (CENPERM)University of CopenhagenCopenhagen KDenmark

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