, Volume 41, Supplement 3, pp 197–206 | Cite as

Treelines Will be Understood Once the Functional Difference Between a Tree and a Shrub Is

  • Christian Körner


Trees are taller than shrubs, grasses, and herbs. What is the disadvantage of being tall so that trees are restricted to warmer regions than low stature life forms? This article offers a brief review of the current state of biological treeline theory, and then explores the significance of tallness from a carbon balance, freezing resistance, and microclimatological perspective. It will be argued that having of a woody stem is neither a burden to the carbon balance nor does it add to the risk of freezing damage. The physiological means of trees to thrive in cold climates are similar to small stature plants, but due to their size, and, thus, closer aerodynamic coupling to air circulation, trees experience critically low temperatures at lower elevation and latitude than smaller plants. Hence, trees reach a limit at treeline for physical reasons related to their stature.


Climate Forest limit Growth Stress Temperature Timberline 



With great pleasure I dedicate this article to Professor Terry Callaghan as part of the festschrift at the occasion of his retirement from directorship at the Abisko Research Station. Much of the treeline theory presented here developed during my sabbatical stays at the station. I thank Jens Paulsen for providing his unpublished statistics on global treeline climatology and Susanna Riedl for the artwork. This paper developed while funded by the European Research Council, advanced Grant 233399, TREELIM.


  1. Alvarez-Uria, P., and C. Körner. 2007. Low temperature limits of root growth in deciduous and evergreen temperate tree species. Functional Ecology 21: 211–218.CrossRefGoogle Scholar
  2. Bernoulli, M., and C. Körner. 1999. Dry matter allocation in treeline trees. Phyton 39: 7–12.Google Scholar
  3. Björklund, L. 1999. Identifying heartwood-rich stands or stems of Pinus sylvestris by using inventory data. Silva Fennica 33: 119–129.Google Scholar
  4. Bosshard, H.H. 1984. Holzkunde, vol. II. Basel: Birkhäuser.Google Scholar
  5. Callaghan, T.V., R.M.M. Crawford, M. Eronen, A. Hofgaard, S. Payette, W.G. Rees, O. Skre, B. Sveinbjörnsson, et al. 2002. The dynamics of the tundra-taiga boundary: An overview and suggested coordinated and integrated approach to research. AMBIO 12: 3–5.Google Scholar
  6. Germino, M.J., and W.K. Smith. 1999. Sky exposure, crown architecture, and low-temperature photoinhibition in conifer seedlings at alpine treeline. Plant, Cell and Environment 22: 407–415.CrossRefGoogle Scholar
  7. Gervais, B.R., and G.M. MacDonald. 2000. A 403-year record of July temperatures and treeline dynamics of Pinus sylvestris from the Kola Peninsula, northwest Russia. Arctic, Antarctic, and Alpine Research 32: 295–302.CrossRefGoogle Scholar
  8. Gould, P.J., and C.A. Harrington. 2008. Extending sapwood—Leaf area relationships from stems to roots in Coast Douglas-fir. Annals of Forest Science. doi: 10.1051/forest:2008067.
  9. Grace, J. 1988. The functional significance of short stature in montane vegetation. In Plant form and vegetation structure, ed. M.J.A. Werger, P.J.M. Van der Aart, H.J. During, and J.T.A. Verhoeven, 201–209. The Hague: SPB Academic Publishing.Google Scholar
  10. Grace, J., S.J. Allen, and C. Wilson. 1989. Climate and the meristem temperatures of plant communities near the tree-lines. Oecologia 79: 198–204.CrossRefGoogle Scholar
  11. Harsch, M.A., P.E. Hulme, M.S. McGlone, and R.P. Duncan. 2009. Are treelines advancing? A global meta-analysis of treeline response to climate warming. Ecology Letters 12: 1040–1049.CrossRefGoogle Scholar
  12. Hijmans, R.J., S.E. Cameron, J.L. Parra, P.G. Jones, and A. Jarvis. 2005. Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology 25: 1965–1978.CrossRefGoogle Scholar
  13. Hoch, G., and C. Körner. 2003. The carbon charging of pines at the climatic treeline: A global comparison. Oecologia 135: 10–21.Google Scholar
  14. Hoch, G., and C. Körner. 2011. Global patterns of mobile carbon stores in trees at high elevation treeline. Global Ecology and Biogeography. doi: 10.1111/j.1466-8238.2011.00731.x.
  15. Hoch, G., A. Richter, and C. Körner. 2003. Non-structural carbohydrates in temperate forest trees. Plant Cell Environ 26: 1067–1081.Google Scholar
  16. Holtmeier, F.-K. 2009. Mountain timberlines. Ecology, patchiness, and dynamics. Berlin: Springer.Google Scholar
  17. Huber, B., and G. Prütz. 1938. Über den Anteil von Fasern, Gefässen und Parenchym am Aufbau verschiedener Hölzer. Holz als Roh- und Werkstoff 1: 377–381.CrossRefGoogle Scholar
  18. Knapic, S., and H. Pereira. 2005. Within-tree variation of heartwood and ring width in maritime pine (Pinus pinaster Ait.). Forest Ecology and Management 210: 81–89.CrossRefGoogle Scholar
  19. Körner, C. 1994. Biomass fractionation in plants: A reconsideration of definitions based on plant functions. In A whole plant perspective on carbon–nitrogen interactions, ed. J. Roy, and E. Garnier, 173–185. The Hague: SPB Academic Publishing.Google Scholar
  20. Körner, C. 1999. Alpine plants: Stressed or adapted? In Physiological plant ecology, ed. M.C. Press, J.D. Scholes, and M.G. Barker, 297–311. Oxford: Blackwell.Google Scholar
  21. Körner, C. 2003. Alpine plant life. Berlin: Springer.CrossRefGoogle Scholar
  22. Körner, C. 2007. Climatic treelines: Conventions, global patterns, causes. Erdkunde 61: 315–324.CrossRefGoogle Scholar
  23. Körner, C. 2008. Winter crop growth at low temperature may hold the answer for alpine treeline formation. Plant Ecology and Diversity 1: 3–11.CrossRefGoogle Scholar
  24. Körner, C. 2012. Alpine treelines. Basel: Springer.CrossRefGoogle Scholar
  25. Körner, C., and J. Paulsen. 2004. A world-wide study of high altitude treeline temperatures. Journal of Biogeography 31: 713–732.CrossRefGoogle Scholar
  26. Körner, C., J. Paulsen, and E.M. Spehn. 2011. A definition of mountains and their bioclimatic belts for global comparison of biodiversity data. Alpine Botany 121: 73–78.Google Scholar
  27. Kullman, L. 1990. Dynamics of altitudinal tree-limits in Sweden: A review. Norsk Geologisk Tidsskrift 44: 103–116.CrossRefGoogle Scholar
  28. Kullman, L. 2007. Tree line population monitoring of Pinus sylvestris in the Swedish Scandes, 1973–2005: Implications for tree line theory and climate change ecology. Journal of Ecology 95: 41–52.CrossRefGoogle Scholar
  29. Larcher, W. 1985. Winter stress in high mountains. In Establishment and tending of subalpine forest: Research and management, ed. H. Turner, and W. Tranquillini. Berichte der Eidgenössischen Anstalt für das forstliche Versuchswesen 270: 11–20.Google Scholar
  30. Matyssek, R. 1985. Der Kohlenstoff-, Wasser-, und Nahrstoffhaushalt der wechselgrünen und immergrünen Koniferen Lärche, Fichte, Kiefer. PhD thesis. Bayreuth, Germany: University of Bayreuth.Google Scholar
  31. Matyssek, R., G. Wieser, K. Patzner, H. Blaschke, and K.H. Haberle. 2009. Transpiration of forest trees and stands at different altitude: Consistencies rather than contrasts? European Journal of Forest Research 128: 579–596.CrossRefGoogle Scholar
  32. Mayr, S. 2007. Limits in water relations. In Trees at their upper limit, ed. G. Wieser, and M. Tausz, 145–162. Berlin: Springer.CrossRefGoogle Scholar
  33. Münster-Swendsen, M. 1987. Index of vigour in Norway spruce (Picea abies Karst.). Journal of Applied Ecology 24: 551–561.CrossRefGoogle Scholar
  34. Oren, R., E.-D. Schulze, R. Matyssek, and R. Zimmermann. 1986. Estimating photosynthetic rate and annual carbon gain in conifers from specific leaf weight and leaf biomass. Oecologia 70: 187–193.CrossRefGoogle Scholar
  35. Paulsen, J., U.M. Weber, and C. Körner. 2000. Tree growth near treeline: Abrupt or gradual reduction with altitude? Arctic, Antarctic, and Alpine Research 32: 14–20.CrossRefGoogle Scholar
  36. Rossi, S., A. Desauriers, T. Anfodillo, and V. Carraro. 2007. Evidence of threshold temperatures for xylogenesis in conifers at high altitudes. Oecologia 152: 1–12.CrossRefGoogle Scholar
  37. Sakai, A., and W. Larcher. 1987. Frost survival of plants. Responses and adaptation. Ecological Studies 62. Berlin: Springer.Google Scholar
  38. Sakai, A., and S. Okada. 1971. Freezing resistance of conifers. Silvae Genetica 20: 91–97.Google Scholar
  39. Sala, A., W. Fouts, and G. Hoch. 2011. Carbon storage in trees: Does relative carbon supply decrease with tree size? In Size- and age-related changes in tree structure and function (Tree Physiology 4), ed. F. C. Meinzer, B. Lachenbruch and T. E. Dawson, 287–306. Berlin: Springer. doi: 10.1007/978-94-007-1242_11.
  40. Schönenberger, W. 2001. Cluster afforestation for creating diverse mountain forest structures—A review. Forest Ecology and Management 145: 121–128.CrossRefGoogle Scholar
  41. Schulze, E.-D., J. Cermak, R. Matyssek, M. Penka, R. Zimmermann, F. Vasicek, W. Gries, and J. Kucera. 1985. Canopy transpiration and water fluxes in the xylem of the trunk of Larix and Picea trees—A comparison of xylem flow, porometer and cuvette measurements. Oecologia 66: 475–483.CrossRefGoogle Scholar
  42. Sellin, A. 1994. Sapwood-heartwood proportion related to tree diameter, age and growth rate in Picea abies. Canadian Journal of Forest Research 24: 1022–1028.CrossRefGoogle Scholar
  43. Smith, W.K., M.J. Germino, T.E. Hancock, and D.M. Johnson. 2003. Another perspective on altitudinal limits of alpine timberlines. Tree Physiology 23: 1101–1112.CrossRefGoogle Scholar
  44. Squeo, A., F. Rada, A. Azocar, and G. Goldstein. 1991. Freezing tolerance and avoidance in high tropical Andean plants: Is it equally represented in species with different plant height? Oecologia 86: 378–382.CrossRefGoogle Scholar
  45. Sterck, F.J., R. Zweifel, U. Sass-Klaassen, and Q. Chowdhury. 2008. Persisting soil drought reduces leaf specific conductivity in Scots pine (Pinus sylvestris) and pubescent oak (Quercus pubescent). Tree Physiology 28: 529–536.CrossRefGoogle Scholar
  46. Stöcklin, J., and C. Körner. 1999. Recruitment and mortality of Pinus sylvestris near the nordic treeline: The role of climatic change and herbivory. Ecological Bulletins 47: 168–177.Google Scholar
  47. Sveinbjörnsson, B., A. Hofgaard, and A. Lloyd. 2002. Natural causes of the tundra-taiga boundary. AMBIO 12: 23–29.Google Scholar
  48. Tranquillini, W. 1979. Physiological ecology of the Alpine Timberline. Tree existence at high altitudes with special references to the European Alps. Ecological Studies 31. Berlin: Springer.Google Scholar
  49. Troll, C. 1973. The upper timberlines in different climatic zones. Arctic and Alpine Research 5: A3–A18.Google Scholar
  50. von Humboldt, A., and A. Bonpland. 1807. Ideen zu einer Geographie der Pflanzen nebst einem Naturgemälde der Tropenländer. Tübingen: F.G. Cotta; Paris: F. Schoell.Google Scholar
  51. Wieser, G. 1997. Carbon dioxide gas exchange of cembran pine (Pinus cembra) at the alpine timberline during winter. Tree Physiology 17: 473–477.CrossRefGoogle Scholar
  52. Wieser, G., and M. Bahn. 2004. Seasonal and spatial variation of woody tissue respiration in a Pinus cembra tree at the alpine timberline in the central Austrian Alps. Trees - Structure and Function 18: 576–580.Google Scholar
  53. Wieser, G., and M. Tausz. 2007. Trees at their upper limit—Treelife limitation at the Alpine Timberline. Dordrecht: Springer.CrossRefGoogle Scholar
  54. Würth, M.K.R., S. Pelaez-Riedl, S.J. Wright, and C. Körner. 2005. Non-structural carbohydrate pools in a tropical forest. Oecologia 143: 11–24.CrossRefGoogle Scholar
  55. Zhu, Y., R.T.W. Siegwolf, W. Durka, and C. Körner. 2010. Phylogenetically balanced evidence for structural and carbon isotope responses in plants along elevational gradients. Oecologia 162: 853–863.CrossRefGoogle Scholar

Copyright information

© Royal Swedish Academy of Sciences 2012

Authors and Affiliations

  1. 1.Institute of BotanyUniversity of BaselBaselSwitzerland

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