Modelling Tundra Vegetation Response to Recent Arctic Warming
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The Arctic land area has warmed by >1 °C in the last 30 years and there is evidence that this has led to increased productivity and stature of tundra vegetation and reduced albedo, effecting a positive (amplifying) feedback to climate warming. We applied an individual-based dynamic vegetation model over the Arctic forced by observed climate and atmospheric CO2 for 1980–2006. Averaged over the study area, the model simulated increases in primary production and leaf area index, and an increasing representation of shrubs and trees in vegetation. The main underlying mechanism was a warming-driven increase in growing season length, enhancing the production of shrubs and trees to the detriment of shaded ground-level vegetation. The simulated vegetation changes were estimated to correspond to a 1.75 % decline in snow-season albedo. Implications for modelling future climate impacts on Arctic ecosystems and for the incorporation of biogeophysical feedback mechanisms in Arctic system models are discussed.
KeywordsArctic tundra vegetation Climate change Shrub expansion Ecosystem modelling LPJ-GUESS Biogeophysical feedbacks
The authors would like to acknowledge the valuable contributions of both Rita Wania and Annett Wolf to the development of process descriptions in LPJ-GUESS. They would also like to thank Dan Hayes (Oak Ridge National Laboratory, USA) for producing the wetland map for the study domain shown in Fig. 1b. The authors acknowledge financial support from the Swedish Research Council FORMAS. This study is a contribution to the Strategic Research Area Modelling the Regional and Global Earth System (MERGE) and to the Nordic Top-Research Initiative DEFROST.
- ACIA. 2005. Arctic Climate Impact Assessment—Scientific Report, 1st ed. New York: Cambridge University Press.Google Scholar
- Arft, A.M., M.D. Walker, J. Gurevitch, J.M. Alatalo, M.S. Bret-Harte, M. Dale, M. Diemer, F. Gugerli, et al. 1999. Responses of tundra plants to experimental warming: Meta-analysis of the International Tundra Experiment. Ecological Monographs 69: 491–511.Google Scholar
- Callaghan, T.V., L.O. Björn, F.S. Chapin III, Y. Chernov, T.R. Christensen, B. Huntley, R.A. Ims, M. Johansson, et al. 2005. Arctic tundra and polar desert ecosystems. In ACIA Arctic Climate Impact Assessment, 243–352. New York: Cambridge University Press.Google Scholar
- Callaghan, T.V., C.E. Tweedie, J. Åkerman, C. Andrews, J. Bergstedt, M.G. Butler, T.R. Christensen, Dorothy Cooley, et al. 2011. Multi-decadal changes in tundra environments and ecosystems: Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF). AMBIO 40: 705–716.CrossRefGoogle Scholar
- Elmendorf, S.C., G.H.R. Henry, R.D. Hollister, R.G. Björk, N. Boulanger-Lapointe, E.J. Cooper, J.H.C. Cornelissen, T.A. Day, et al. 2012. Plot-scale evidence of tundra vegetation change and links to recent summer warming. Nature Climate Change 2. doi: 10.1038/nclimate1465.
- Goetz, S.J., H.E. Epstein, U.S. Bhatt, G.J. Jia, J.O. Kaplan, H. Lischke, Q. Yu, A. Bunn, et al. 2011. Recent changes in arctic vegetation: Satellite observations and simulation model predictions. In Eurasian Arctic land cover and land use in a changing climate, ed. G. Gutman, and A. Reissell, 9–36. Dordrecht: Springer.Google Scholar
- Hickler, T., K. Vohland, J. Feehan, P.A. Miller, S. Fronzek, T. Giesecke, I. Kuehn, T. Carter, B. Smith, and M. Sykes. 2012. Projecting tree species-based climate-driven changes in European potential natural vegetation with a generalized dynamic vegetation model. Global Ecology and Biogeography 21: 50–63.CrossRefGoogle Scholar
- Kaplan, J.O., N.H. Bigelow, I.C. Prentice, S.P. Harrison, P.J. Bartlein, T.R. Christensen, W. Cramer, N.V. Matveyeva, et al. 2003. Climate change and Arctic ecosystems: 2. Modeling, paleodata-model comparisons, and future projections. Journal of Geophysical Research 108. doi: 10.1029/2002JD002559.
- McBean, G.A., G. Alekseev, D. Chen, E. Forland, J. Fyfe, P. Groisman, H. Melling, R. Vose, et al. 2005. Arctic climate past and present. In ACIA—Arctic Climate Impact Assessment, 22–60. New York: Cambridge University Press.Google Scholar
- McGuire, A.D., T.R. Christensen, D. Hayes, A. Heroult, E. Euskirchen, J.S. Kimball, C. Koven, P. Lafleur, et al. 2012. An assessment of the carbon balance of arctic tundra: Comparisons among observations, process models, and atmospheric inversions. Biogeosciences Discussions 9: 4543–4594.CrossRefGoogle Scholar
- 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 understorey. Global Change Biology 16: 1820–1829.CrossRefGoogle Scholar
- ORNL-DAAC. 2011. MODIS subsetted land products, Collection 5. http://daac.ornl.gov/MODIS/modis.html. Oak Ridge, Tennessee: ORNL-DAAC. Accessed 7 April 2011.
- Roberts, A., J. Cassano, R. Döscher, L. Hinzman, M. Holland, H. Mitsudera, A. Sumi, and J.E. Walsh. 2010. A science plan for regional Arctic System Modelling. International Arctic Research Center Technical Papers 10-0001. Fairbanks, Alaska: IARC, University of Alaska Fairbanks.Google Scholar
- Smith, B., A. Aasa, R. Ahas, T. Blenckner, T.V. Callaghan, J. de Chazal, C. Humborg, A.M. Jönsson, A.M., et al. 2008a. Climate-related change in terrestrial and freshwater ecosystems. In Assessment of Climate Change for the Baltic Sea Basin, 221–308. Berlin: Springer.Google Scholar
- Sonesson, M., and J. Hoogesteger. 1983. Recent treeline dynamics (Betula pubescens Ehrh. ssp. tortuosa (ledeb.) Nyman) in northern Sweden. Nordicana 47: 47–54.Google Scholar
- Van Bogaert, R., K. Haneca, J. Hoogesteger, C. Jonasson, M. De Dapper, and T.V. Callaghan. 2011. A century of tree line changes in sub-Arctic Sweden shows local and regional variability and only a minor influence of 20th century climate warming. Journal of Biogeography 38: 907–921.CrossRefGoogle Scholar
- Walker, M.D., C.H. Wahren, R.D. Hollister, G.H.R. Henry, L.E. Ahlquist, J.M. Alatalo, M.S. Bret-Harte, M.P. Calef, et al. 2006. Plant community responses to experimental warming across the tundra biome. Proceedings of the National Academy of Sciences of the United States of America 103: 1342–1346.CrossRefGoogle Scholar