• [1]
    Intergovernmental Panel on Climate Change, 2001. Climate change 2001: impacts, adaptation, and vulnerability. IPCC Third Assessment Report, Cambridge University Press, Cambridge, 2001
  • [2]
    Warrick, R.A., Shugart, H.H., Antonovsky, M., Tarrant, J.R., Tucker, C.J. The effects of increased CO2 and climatic change on terrestrial ecosystems. In: Bolin, B. (Ed.), The Greenhouse Effect, Climatic Change and Ecosystems, Chichester, 1986, pp. 363–392
  • [3]
    Shaver, G.R., Billings, W.D., Chapin, F.S., Giblin, A.E., Nadelhoffer, K.J., Oechel, W.C., Rastetter, E.B. (1992) Global change and the carbon balance of arctic ecosystems. Bioscience 42, 433441.
  • [4]
    Jonasson, S., Havstrom, M., Jensen, M., Callaghan, T.V. (1993) In situ mineralization of nitrogen and phosphorus of arctic soils after perturbations simulating climate-change. Oecologia 95, 179186.
  • [5]
    Chapin, F.S., Shaver, G.R., Kedrowski, R.A. (1986) Environmental controls over carbon, nitrogen and phosphorus fractions in Eriophorum vaginatum in Alaskan tussock tundra. J. Ecol. 74, 167195.
  • [6]
    Shaver, G.R., Chapin, F.S. (1986) Effect of fertilizer on production and biomass of tussock tundra, Alaska, USA. Arct. Antarct. Alp. Res. 18, 261268.
  • [7]
    van Wijk, M.T., Clemmensen, K.E., Shaver, G.R., Williams, M., Callaghan, T.V., Chapin, F.S., Cornelissen, J.H.C., Gough, L., Hobbie, S.E., Jonasson, S., Lee, J.A., Michelsen, A., Press, M.C., Richardson, S.J., Rueth, H. (2004) Long-term ecosystem level experiments at Toolik Lake, Alaska, and at Abisko, Northern Sweden: generalizations and differences in ecosystem and plant type responses to global change. Global Change Biol. 10, 105123.
  • [8]
    Nadelhoffer, K.J., Giblin, A.E., Shaver, G.R., Laundre, J.A. (1991) Effects of temperature and substrate quality on element mineralization in six arctic soils. Ecology 72, 242253.
  • [9]
    Tolvanen, A., Henry, G.H.R. (2001) Responses of carbon and nitrogen concentrations in high arctic plants to experimental warming. Can. J. Bot. 79, 711718.
  • [10]
    F.S. Chapin R.L. Jefferies J.F. Reynolds G.R. Shaver J. Svoboda Arctic plant physiological ecology: a challenge for the future F.S. Chapin R.L. Jefferies J.F. Reynolds G.R. Shaver Arctic Ecosystems in a Changing Climate: An Ecophysiological Perspective 1992 Academic Press San Diego 3 8.
  • [11]
    D.M. Chapin C.S. Bledsoe Nitrogen fixation in arctic plant communities F.S. Chapin R.L. Jefferies J.F. Reynolds G.R. Shaver Arctic Ecosystems in a Changing Climate: An Ecophysiological Perspective 1992 Academic Press San Diego 301 319.
  • [12]
    Chapin, F.S., Shaver, G.R., Giblin, A.E., Nadelhoffer, K.J., Laundre, J.A. (1995) Responses of arctic tundra to experimental and observed changes in climate. Ecology 76, 694711.
  • [13]
    Arft, A.M., Walker, M.D., Gurevitch, J., Alatalo, J.M., Bret-Harte, M.S., Dale, M., Diemer, M., Gugerli, F., Henry, G.H.R., Jones, M.H., Hollister, R.D., Jonsdottir, I.S., Laine, K., Levesque, E., Marion, G.M., Molau, U., Molgaard, P., Nordenhall, U., Raszhivin, V., Robinson, C.H., Starr, G., Stenstrom, A., Stenstrom, M., Totland, O., Turner, P.L., Walker, L.J., Webber, P.J., Welker, J.M., Wookey, P.A. (1999) Responses of tundra plants to experimental warming: meta-analysis of the International Tundra Experiment. Ecol. Monogr. 69, 491511.
  • [14]
    Henry, G.H.R. Effects of long-term experimental warming on High Arctic tundra ecosystems. Integr. Comp. Biol. 42, 2002, 1243..
  • [15]
    Shaver, G.R., Chapin, F.S. (1995) Long-term responses to factorial, NPK fertilizer treatment by Alaskan wet and moist tundra sedge species. Ecography 18, 259275.
  • [16]
    Muc, M., Freedman, B., Svoboda, J. (1989) Vascular plant communities of a polar oasis at Alexandra Fiord (79°N), Ellesmere Island. Can. J. Bot. 67, 11261136.
  • [17]
    L.C. Bliss N.V. Matveyeva Circumpolar arctic vegetation F.S. Chapin R.L. Jefferies J.F. Reynolds G.R. Shaver Arctic Ecosystems in a Changing Climate: An Ecophysiological Perspective 1992 Academic Press San Diego 301 319.
  • [18]
    Svoboda, J., Freedman, B., Eds. Ecology of a Polar Oasis, Alexandra Fiord, Ellesmere Island, Canada 1994, Captus University Publications, Toronto.
  • [19]
    Marion, G.M., Henry, G.H.R., Freckman, D.W., Johnstone, J., Jones, G., Jones, M.H., Levesque, E., Molau, U., Molgaard, P., Parson, A.N., Svoboda, J., Virginia, R. (1997) Open top designs for manipulating field temperature in high-latitude ecosystems. Global Change Biol. 3 (Suppl. 1), 2032.
  • [20]
    Larson, D.W., Kershaw, K.A. (1975) Measurement of CO2 exchange in lichens: a new method. Can. J. Bot. 53, 15351541.
  • [21]
    C. Labine Meteorology and climatology of the Alexandra Fiord lowland J. Svoboda B. Freedman Ecology of a Polar Oasis, Alexandra Fiord, Ellesmere Island, Canada 1994 Captus University Publications Toronto 23 39.
  • [22]
    STATISTICA (data analysis software system), StatSoft, Inc., Tulsa, OK, USA, 2002
  • [23]
    Widmer, F., Shaffer, B.T., Porteous, L.A., Seidler, R.J. (1999) Analysis of nifH gene pool complexity in soil and litter at a Douglas Fir forest site in the Oregon Cascade mountain range. Appl. Environ. Microbiol. 65, 374380.
  • [24]
    Kruskal, J.B. (1964) Nonmetric multidimensional scaling: a numerical method. Psychometrika 29, 115129.
  • [25]
    B. McCune J.B. Grace Analysis of Ecological Communities 2002 MjM Software Gleneden Beach.
  • [26]
    Hartley, A.E., Neill, C., Melillo, J.M., Crabtree, R., Bowles, F.P. (1999) Plant performance and soil nitrogen mineralization in response to simulated climate change in subarctic dwarf shrub heath. Oikos 86, 331343.
  • [27]
    Callaghan, T.V., Press, M.C., Lee, J.A., Robinson, D.L., Anderson, C.W. (1999) Spatial and temporal variability in the responses of arctic terrestrial ecosystems to environmental change. Polar Res. 18, 191197.
  • [28]
    Zielke, M., Stine Ekker, A., Olsen, R.A., Spjelkavik, S., Solheim, B. (2002) The influence of abiotic factors on biological nitrogen fixation in different types of vegetation in the High Arctic, Svalbard. Arct. Antarct. Alp. Res. 34, 293299.
  • [29]
    Henry, G.H.R., Svoboda, J. (1986) Dinitrogen fixation (Acetylene Reduction) in high arctic sedge meadows. Arct. Alp. Res. 18, 181187.
  • [30]
    Vitousek, P.M., Cassman, K., Cleveland, C., Crews, T., Field, C.B., Grimm, N.B., Howarth, R.W., Marino, R., Martinelli, L., Rastetter, E.B., Sprent, J.I. (2002) Towards an ecological understanding of biological nitrogen fixation. Biogeochemistry 57, 145.
  • [31]
    Vitousek, P.M., Field, C.B. (1999) Ecosystem constraints to symbiotic nitrogen fixers: a simple model and its implications. Biogeochemistry 46, 179202.
  • [32]
    Chapin, D.M., Bliss, L.C., Bledsoe, L.J. (1991) Environmental-regulation of nitrogen-fixation in a high arctic lowland ecosystem. Can. J. Bot. 69, 27442755.
  • [33]
    Liengen, T. (1999) Environmental factors influencing the nitrogen fixation activity of free-living terrestrial cyanobacteria from a high arctic area, Spitsbergen. Can. J. Microbiol. 45, 573581.
  • [34]
    Piceno, Y.M., Lovell, C.R. (2000) Stability in natural bacterial communities. I. Nutrient addition effects on rhizosphere diazotroph assemblage composition. Microb. Ecol. 39, 3240.
  • [35]
    Solheim, B., Endal, A., Vigstad, H. (1996) Nitrogen fixation in arctic vegetation and soil from Svalbard, Norway. Polar Biol. 16, 3540.
  • [36]
    Zogg, G.P., Zak, D.R., Ringelberg, D.B., Macdonald, N.W., Pregitzer, K.S., White, D.C. (1997) Compositional and functional shifts in microbial communities due to soil warming. Soil Sci. Soc. Am. J. 61, 475481.
  • [37]
    Paul, E.A., Clark, F.E. Soil Microbiology and Biochemistry 1996, Academic Press, San Diego pp. 27–30.
  • [38]
    Ruess, L., Michelsen, A., Schmidt, I.K., Jonasson, S. (1999) Simulated climate change affecting microorganisms, nematode density and biodiversity in subarctic soils. Plant Soil 212, 6373.
  • [39]
    Schmidt, I.K., Jonasson, S., Shaver, G.R., Michelsen, A., Nordin, A. (2002) Mineralization and distribution of nutrients in plants and microbes in four arctic ecosystems: responses to warming. Plant Soil 242, 93106.
  • [40]
    Tan, X.Y., Hurek, T., Reinhold-Hurek, B. (2003) Effect of N-fertilization, plant genotype and environmental conditions on nifH gene pools in roots of rice. Environ. Microbiol. 5, 10091015.