The Botanical Review

, Volume 75, Issue 2, pp 163–190 | Cite as

The Altitude of Alpine Treeline: A Bellwether of Climate Change Effects

  • William K. Smith
  • Matthew J. Germino
  • Daniel M. Johnson
  • Keith Reinhardt


Because of the characteristically low temperatures and ambient CO2 concentrations associated with greater altitudes, mountain forests may be particularly sensitive to global warming and increased atmospheric CO2. Moreover, the upper treeline is probably the most stressful location within these forests, possibly providing an early bellwether of forest response. Most treeline studies of the past century, as well as recently, have correlated temperatures with the altitudinal limits observed for treelines. In contrast, investigations on pre-establishment seedlings, the most vulnerable life stage of most tree species, are rare. There appears to be specific microclimatic factors dictated by wind and sky exposure that limit seedling survival, and also generate the distorted tree forms commonly observed at treeline. Seedling survival appears critical for creating the biological facilitation of microclimate at the community level which is necessary for the growth of seedlings to normal tree stature, forming new subalpine forest at a higher altitude.


Treeline Timberline Ecotone Seedling Facilitation Climate 


Es posible que—a causa de características que están asociadas con altitudes más altas: las bajas temperaturas y las concentraciones ambientales de dióxido de carbono—los bosques en las montañas están extra sensibles al calentamiento global y el aumento de dióxido de carbono en la atmósfera. El borde superior del bosque es probablemente el lugar con la más estrés y proviene uno de los primeros avisos de cómo reaccionará el bosque entero. En el pasado y hoy en día, la mayoría de los estudios del borde del bosque ha conectado la temperatura con los límites de la altitud. En contraste, investigaciones de árboles infantiles son raras, y la infancia de los árboles es el período de vida más vulnerable. Aparece que hay factores micro-climáticos dictados por la exposición del viento y cielo que limitan la sobrevivencia de los árboles infantiles, y que generan árboles deformados observados al borde del bosque. Es más, la sobrevivencia de árboles infantiles es crítica para crear la facilitación biológica del micro-clima en una comunidad arbolada. Esta facilitación es necesaria para el crecimiento de árboles infantiles a árboles maduros, los que forman un nuevo bosque subalpino en una altitud más alta.

Literature Cited

  1. Ainsworth, E. A. & S. P. Long. 2005. What have we learned from 15 years of free-air CO2 enrichment? A meta-analytic review of the responses of photosynthesis, canopy properties, and plant production to rising CO2. New Phytologist 165: 351–372.PubMedCrossRefGoogle Scholar
  2. ——— & A. Rogers. 2007. The response of photosynthesis and stomatal conductance to rising CO2: mechanisms and environmental interactions. Plant, Cell & Environment 30: 258–270.CrossRefGoogle Scholar
  3. Alvarez-Uria, P. & C. Körner. 2007. Low temperature limits of root growth in deciduous and evergreen temperate tree species. Functional Ecology 21: 211–218.CrossRefGoogle Scholar
  4. Andrews, T. & P. M. Foster. 2008. CO2 forcing induces semi-direct effects with consequences for climate feedback interpretations. Geophysical Letters 35: L04802. doi:10.1029/2007GL032273.CrossRefGoogle Scholar
  5. Arno, S. F. 1984. Timberline, mountain and arctic frontiers. The Mountaineers, Seattle.Google Scholar
  6. Bader, M. Y., I. van Geloof & M. Rietkerk. 2007. High solar radiation hinders tree establishment above the alpine treeline in northern Ecuador. Plant Ecology 191: 33–45.CrossRefGoogle Scholar
  7. Ball, M. C., V. S. Hodges & G. P. Laughlin. 1991. Cold-induced photoinhibition limits regeneration of snow gum at tree line. Functional Ecology 5: 663–668.CrossRefGoogle Scholar
  8. Bekker, M. F. 2005. Positive feedback between tree establishment and patterns of subalpine forest advancement, Glacier National Park, Montana, USA. Arctic, Antarctic, and Alpine Research 37: 97–107.CrossRefGoogle Scholar
  9. ———, G. P. Malanson, K. J. Alftine & D. M. Cairns. 2001. Feedback and pattern in computer simulations of the alpine treeline ecotone. Pages 71-82 in A. C. Millington, S. J. Walsh, & P. E. Osborne (eds.), GIS and remote sensing applications in biogeography and ecology. Kluwer Academic, Boston.Google Scholar
  10. Boerner, R. E. J. & J. A. Brinkman. 1996. Ten years of tree seedling establishment and mortality in an Ohio deciduous forest complex. Bulletin of the Torrey Botanical Club 123: 309–317.CrossRefGoogle Scholar
  11. Bridle, J. R. & T. H. Vines. 2006. Limits to evolution at range margins: when and why does adaptation fail. Trends in Ecology and Evolution 22: 140–147.PubMedCrossRefGoogle Scholar
  12. Brodersen, C. R., M. J. Germino & W. K. Smith. 2006. Photosynthesis during an episodic drought in Abies lasiocarpa and Picea engelmannii across an alpine tree line. Artic, Antarctic and Alpine Research 38: 34–41.CrossRefGoogle Scholar
  13. Brooker, R. W., F. T. Maestre, R. M. Callaway, C. Lortie, L. A. Cavieres, G. Kunstler, P. Liancourt, K. Tielbörger, J. M. L. Travis, F. Anthelme F. C. Armas, L. Coll, E. Corcket, S. Delzon, E. Forey, Z. Kikvidze, J. Olofsson, F. Pugnaire, C. L. Quiroz, P. Saccone, K. Schiffers, M. Seifan, B. Touzard & R. Michalet. 2008. Facilitation in plant communities: The past, the present, and the future. Journal of Ecology 96: 18–34.CrossRefGoogle Scholar
  14. Büntgen, U., D. C. Frank, M. Schmidhalter, T. Burkhard, B. Neuwirth, M. Seifert & J. Esper. 2006. Growth/climate response shift in a long subalpine spruce chronology. Trees 20: 99–110.CrossRefGoogle Scholar
  15. Butler, D. R., G. P. Malanson & L. M. Resler. 2004. Turf-banked terrace treads and risers, turf exfoliation, and possible relationships with advancing tree line. Catena 58: 259–274.CrossRefGoogle Scholar
  16. Cairns, D. M. 2005. Simulating carbon balance at tree line for krummholz and dwarf tree growth forms. Ecological Modeling 187: 314–328.CrossRefGoogle Scholar
  17. ——— & J. Moen. 2004. Herbivory influences tree lines. Journal of Ecology 92: 1019–1024.CrossRefGoogle Scholar
  18. Chapman, S. K., J. A. Langley, S. C. Hart & G. W. Koch. 2006. Plants actively control nitrogen cycling: Uncorking the microbial bottleneck. New Phytologist 169: 27–34.PubMedCrossRefGoogle Scholar
  19. Choler, P., R. Michalet & R. M. Callaway. 2001. Facilitation and competition along gradients in alpine plant communities. Ecology 82: 3295–3308.Google Scholar
  20. Cui, M. & W. K. Smith. 1990. Photosynthesis and water relations of young seedlings of Abies lasiocarpa with high natural mortality. Tree Physiology 8: 37–46.Google Scholar
  21. ——— & ———. 1991. Seedling microenvironment, gas exchange and survival during first-year establishment in subalpine conifers. Tree Physiology 10: 44–53.Google Scholar
  22. Dale, V. H., L. A. Joyce, S. McNulty, R. P. Neilson, M. P. Ayres, M. D. Flannigan, P. J. Hanson, L. C. Irland, A. E. Lugo, C. J. Peterson, D. Simberloff, F. J. Swanson, B. J. Stocks & B. M. Wotton. 2001. Climate change and forest disturbance. Bioscience 51: 723–734.CrossRefGoogle Scholar
  23. De Graaff, M. A., K. J. van Groenigen, J. Six, B. Hungate & C. van Kessel. 2006. Interactions between plant growth and soil nutrient cycling under elevated CO2: A meta-analysis. Global Change Biology 12: 2077–2091.CrossRefGoogle Scholar
  24. DeLucia, E. H., D. J. Moore & R. J. Norby. 2005. Contrasting responses of forest ecosystems to rising atmospheric CO2: Implications for the global C cycle. Global Biogeochemical Cycles 19: GB3006.CrossRefGoogle Scholar
  25. ———, C. L. Casteel, P. D. Nabity & B. F. O’Neil. 2008. Insects take a bigger bite out of plants in a warmer, higher carbon dioxide world. Proceedings of the National Academy of Science 105: 1781–1782.CrossRefGoogle Scholar
  26. Di Pasquale, G., M. Marziano, S. Impagliazzo, C. Lubritto, A. De Natale & M. Y. Bader. 2008. The Holocene tree line in the northern Andes (Ecuador): First evidence from soil charcoal. Paleogeography, Paleoclimatology, Paleoecology 259: 17–34.CrossRefGoogle Scholar
  27. Egerton, J. J. G., J. G. C. Banks, A. Gibson, R. B. Cunningham & M. C. Ball. 2000. Facilitation of seedling establishment: reduction in irradiance enhances winter growth of Eucalyptus pauciflora. Ecology 81: 1437–1446.Google Scholar
  28. Finzi, A. C., D. J. P. Moore, E. H. DeLucia, J. Lichter, K. S. Hofmockel, R. B. Jackson, H. S. Kim, R. Matamala, H. R. McCarthy, R. Oren, J. S. Pippen & W. H. Schlesinger. 2006. Progressive nitrogen limitation of ecosystem processes under elevated CO2 in a warm-temperate forest. Ecology 87: 15–25.PubMedCrossRefGoogle Scholar
  29. Friend, A. D. & F. I. Woodward. 1990. Evolutionary and ecophysiological responses of mountain plants to the growing season environment. Advances in Ecological Research 20: 59–124.CrossRefGoogle Scholar
  30. Gale, J. 1972a. The availability of carbon dioxide for photosynthesis at high altitudes: Theoretical considerations. Ecology 53: 494–497.CrossRefGoogle Scholar
  31. ———. 1972b. Elevation and transpiration. Some theoretical considerations, with special reference to Mediterranean type climates. Journal of Applied Ecology 9: 691–702.CrossRefGoogle Scholar
  32. ———. 1973. Experimental evidence for the effect of barometric pressure on photosynthesis and transpiration. Ecology and Conservation (UNESCO) 5: 289–293.Google Scholar
  33. ———. 2004. Plants and altitude—revisited. Annals of Botany 94: 199–200.PubMedCrossRefGoogle Scholar
  34. Geber, M. A. 2008. To the edge: Studies of species range limits. New Phytologist 178: 228–230.PubMedCrossRefGoogle Scholar
  35. Geiger, T. & C. Leuschner. 2004. Altitudinal change in needle water relations of Pinus canariensis and possible evidence of a drought-induced alpine timberline on Mt. Teide, Tenerife. Flora 199: 100–109.Google Scholar
  36. Germino, M. J. & W. K. Smith. 1999. Sky exposure, crown architecture, and low temperature photoinhibition in conifer seedlings at alpine tree line. Plant, Cell & Environment 22: 407–415.CrossRefGoogle Scholar
  37. ——— & ———. 2001. Interactions of microsite, plant form, and low-temperature photoinhibition in alpine plants. Artic, Antarctic, and Alpine Research 32: 388–396.CrossRefGoogle Scholar
  38. ———, C. A. C. Resor & W. K. Smith. 2002. Influence of microsite and plant form on photosynthetic responses to frost and high sunlight. Plant Ecology 162: 157–168.CrossRefGoogle Scholar
  39. ———, N. J. Hasselquist, T. M. McGonigle, W. K. Smith & P. Sheridan. 2006. Colonization of conifer seedling roots by fungal mycelium in an alpine-tree line ecotone: Relationships to microsite, developmental stage, and ecophysiology of seedlings. Canadian Journal of Forest Research 36: 901–909.CrossRefGoogle Scholar
  40. Gimenez-Benavides, L., A. Escudero & J. M. Iriondo. 2007. Local adaptation enhances seedling recruitment along an altitudinal gradient in a high-mountain Mediterranean plant. Annals of Botany 99: 723–734.PubMedCrossRefGoogle Scholar
  41. Giorgi, F. 2001. Emerging patterns of simulated regional climatic changes for the 21st century due to anthropogenic forcings. Geophysical Research Letters 28: 3317–3326.CrossRefGoogle Scholar
  42. Goldenberg, S. B., C. W. Landsea, A. M. Mestas-Nunez & W. M. Gray. 2001. The recent increase in Atlantic hurricane activity: causes and implications. Science 293: 474–479.PubMedCrossRefGoogle Scholar
  43. Gosz, P. G. 1993. Ecological hierarchies. Ecological Applications 3: 369–376.CrossRefGoogle Scholar
  44. Grace, J., F. Berninger & L. Nagy. 2002. Impacts of climate change on the tree line. Annals of Botany 90: 537–544.PubMedCrossRefGoogle Scholar
  45. Grabherr, G., M. Gottfried & H. Pauli. 1994. Climate effects on Mountain plants. Nature 369: 448.CrossRefGoogle Scholar
  46. Graumlich, L. J. 1991. Subalpine tree growth, climate, and increasing C02: an assessment of recent growth trends. Ecology 72: 1–11.CrossRefGoogle Scholar
  47. ———, & L. B. Brubaker. 1986. Reconstruction of annual temperature (1590–1979) for Longmire, Washington, derived from tree rings. Quaternary Research 25: 223–234.CrossRefGoogle Scholar
  48. Gregory, J. & M. Webb. 2008. Tropospheric adjustment induces a cloud component in CO2 forcing. Journal of Climate 21: 58–63.CrossRefGoogle Scholar
  49. Gutschick, V. P. & H. BassririRad. 2003. Extreme events as shaping physiology, ecology, and evolution of plants: toward a unified definition and evaluation of their consequences. New Phytologist 160: 21–42.CrossRefGoogle Scholar
  50. Hadley, J. L. & W. K. Smith. 1987. Influence of krummholz mat microclimate on needle physiology and survival. Oecologia 73: 82–90.CrossRefGoogle Scholar
  51. Handa, I. T., F. Hagedorn & S. Hättenschwiler. 2008. No stimulation in root production in response to 4 years of in situ CO2 enrichment at the Swiss treeline. Functional Ecology 22: 348–358.CrossRefGoogle Scholar
  52. Harcombe, P. A. 1987. Tree life tables. Bioscience 37: 557–568.CrossRefGoogle Scholar
  53. Hasselquist, N. J., M. J. Germino, T. McGonigle & W. K. Smith. 2005. Variability of Cenococcum colonization and its ecophysiological significance for young conifers at alpine tree line. New Phytologist 165: 867–873.PubMedCrossRefGoogle Scholar
  54. Hättenschwiler, S. & W. K. Smith. 1999. Natural seedling occurrence in treeline conifers: a case study from the central Rocky Mountains, USA. Acta Oecologia 20: 219–224.CrossRefGoogle Scholar
  55. ———, T. Handa, L. Egli, R. Asshoff, W. Amman & C. Körner. 2002. Atmospheric CO2 enrichment of alpine tree line conifers. New Phytologist 156: 363–375.CrossRefGoogle Scholar
  56. Hayden, B. P. & N. R. Hayden. 2003. Decadal and century-long storminess changes at long term ecological research sites. Pages 262–285 in D. Greenland, D. G. Goodin, R. C. Smith (eds.), Climate variability and ecosystem climate variability and response at long-term ecological research sites. Oxford University Press, New York.Google Scholar
  57. Hoch, G., M. Popp & C. Körner. 2002. Altitudinal increase of mobile carbon pools in Pinus cembra suggests sink limitation of growth at the Swiss tree line. Oikos 98: 361–374.CrossRefGoogle Scholar
  58. Holtmeier, F. K. 2003. Mountain timberlines: ecology, patchiness, and dynamics. Advances in Global Change Research 14 Dordrecht, Boston.Google Scholar
  59. ——— & G. Broll. 2005. Sensitivity and response of the northern hemisphere altitudinal and polar tree lines to environmental change at landscape and local scales. Global Ecology and Biogeography 14: 395–410.CrossRefGoogle Scholar
  60. ——— & ———. 2007. Tree line advance—driving processes and adverse factors. Landscape Online 1: 1–33. doi:10.3097/LO.200701.CrossRefGoogle Scholar
  61. Hyvönen, R., G. Ãgren, S. Linder, T. Persson, M. F. Cotrufo, A. Ekblad, M. Freeman, A. Grelle, I. A. Janssens, P. G. Jarvis, S. Kellomaki, A. Lindroth, D. Loustau, T. Lundmark, R. J. Norby, R. Oren, K. Pliegaard, M. G. Ryan, B. D. Sigurdsson, G. Strömgren, M. van Oijen & G. Wallin. 2007. The likely impact of elevated CO2, nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: A literature review. New Phytologist 173: 463–480.PubMedCrossRefGoogle Scholar
  62. IPCC Climate Change. 2007. Impacts, adaptation, and vulnerability. Contribution of working Group II, 4th Assessment Report of the International Panel on Climate Change (IPCC). (,htm)
  63. Johnson, D. M. & W. K. Smith. 2007a. Limitations to photosynthetic carbon gain in timberline Abies lasiocarpa seedlings during prolonged drought. Canadian Journal of Forest Research 37: 568–597.CrossRefGoogle Scholar
  64. ——— & ———. 2007b. Cloud immersion alters microclimate, photosynthesis and water relations in Rhododendron catawbiense and Abies fraseri seedlings in the southern Appalachian Mountains, USA. Tree Physiology 28: 385–392.Google Scholar
  65. ———, M. J. Germino & W. K. Smith. 2004. Abiotic factors limiting photosynthesis in Abies lasiocarpa and Picea engelmannii seedlings below and above the alpine timberline. Tree Physiology 24: 377–386.PubMedGoogle Scholar
  66. Jordan, D. N. & W. K. Smith. 1995. Microclimate factors influencing the frequency and duration of growth season frost in subalpine plants. Agricultural and Forest Meteorology 77: 17–30.CrossRefGoogle Scholar
  67. Juntunen, V. & S. Neuvonen. 2006. Natural regeneration of Scots pine and Norway spruce close to the timberline in northern Finland. Silva Fennica 40: 443–458.Google Scholar
  68. ———, ———, Y. Norokopi & T. Tasanen. 2002. Potential for timberline advance in northern Finland, as revealed by monitoring during 1983-99. Artic 55: 348–361.Google Scholar
  69. Körner, C. 1998. A reassessment of high elevation tree line positions and their explanation. Oecologia 115: 445–459.CrossRefGoogle Scholar
  70. ———. 2003a. Alpine plant life: functional plant ecology of high mountain ecosystems, 2nd ed. Springer, Berlin, 77-99Google Scholar
  71. ———. 2003b. Carbon limitation in trees. Journal of Ecology 91: 4–7.CrossRefGoogle Scholar
  72. ———. 2005. The green cover of mountains in a changing environment. In: U. M Hubter, H. K. M. Bugmann, M. E. Reasoner eds. Global change and mountain regions: An overview of current knowledge. 367–375. Advances in Global Change Research 23, Dordrecht.CrossRefGoogle Scholar
  73. ———. 2006. Plant CO2 responses: an issue of definition, time and resource supply. New Phytologist 172: 393–411.PubMedCrossRefGoogle Scholar
  74. ———. 2007. Climatic tree lines: Conventions, global patterns, causes. Erdkunde 61: 316–324.CrossRefGoogle Scholar
  75. ——— & J. Paulsen. 2004. A world-wide study of high-altitude tree line temperatures. Journal of Biogeography 31: 713–732.Google Scholar
  76. Kullman, L. 2007. Tree line population monitoring of Pinus sylvestris in the Swedish Scandes, 1973–2005: Implications for climate change ecology. Journal of Ecology 95: 41–52.CrossRefGoogle Scholar
  77. Kytöviita, A-M. & A. L. Ruotsalainen. 2007. Mycorrhizal benefit in two low arctic herbs increases with increasing temperature. American Journal of Botany 94: 1309–1315.CrossRefGoogle Scholar
  78. Lambers, H. & H. Poorter. 1992. Inherent variation in growth rate between higher plants: A search for physiological causes and ecological consequences. Advances in Ecological Research 23: 188–242.CrossRefGoogle Scholar
  79. League, K. & T. Veblen. 2006. Climatic variability and episodic Pinus ponderosa establishment along the forest-grassland ecotones of Colorado. Forest Ecology and Management 228: 98–107.CrossRefGoogle Scholar
  80. Leuschner, C. 2000. Are high elevations in tropical mountains arid environments for plants? Ecology 81: 1425–1436.Google Scholar
  81. Leuzinger, S. & C. Körner. 2007. Tree species diversity affects canopy leaf temperatures in a mature temperate forest. Agricultural and Forest Meteorology 146: 29–37.CrossRefGoogle Scholar
  82. Li, M., W. Xiao, S. Wang, G. Cheng, P. Cherubini, X. Cai, L. Liu, X. Wang & W. Zhu. 2008. Mobile carbohydrates in Himalayan tree line trees I. Evidence for carbon gain limitation but not for growth limitation. Tree Physiology 28: 1287–1296.PubMedGoogle Scholar
  83. Loveys, B. R., I. Scheurwater, T. L. Pons, A. H. Fitter & O. K. Atkin. 2002. Growth temperature influences the underlying components of relative growth rate: An investigation using inherently fast- and slow-growing plant species. Plant, Cell & Environment 25: 975–988.CrossRefGoogle Scholar
  84. Maher, E. L. & M. J. Germino. 2006. Microsite differentiation among conifer species during seedling establishment at alpine tree line. Ecoscience 13: 334–341.CrossRefGoogle Scholar
  85. Malanson, G. P. 1997. Effects of feedback and seed rain on ecotone patterns. Landscape Ecology 12: 27–38.CrossRefGoogle Scholar
  86. ———. 2001. Complex responses to global change at alpine treeline. Physical Geography 22: 333–342.Google Scholar
  87. ———, D. R. Butler, D. B. Fagre, S. J. Walsh, D. F. Tomback, L. D. Daniels, L. M. Resler, W. K. Smith, D. L. Weis, D. L. Peterson, A. G. Bunn, C. H. Hiemstra, D. Liptzin, P. S. Bourgeron, Z. Shen & C. I. Miller. 2007. Physical Geography 28: 378–396.Google Scholar
  88. Maurol, C., H. S. J. Lee & P. G. Jarvis. 1999. Increased growth in elevated CO2: An early, short-term response? Global Change Biology 5: 623–633.CrossRefGoogle Scholar
  89. Mayr, S., A. Gruber & H. Bauer. 2003. Repeated freeze–thaw cycles induce embolism in drought stressed conifers (Norway spruce, stone pine). Planta 217: 436–441.PubMedCrossRefGoogle Scholar
  90. ———, ——— & ———. 2007. Limits in water relations. Pages 145–162 in G. Wieser, M. Tuasz (eds.), Trees at their upper limit: tree life limitations at the alpine tree line. Plant Ecophysiology 5, Springer, Dordrecht.Google Scholar
  91. McNulty, S. G. & J. D. Aber. 2001. US national climate change assessment on forest ecosystems: An introduction. Bioscience 51: 720–722.CrossRefGoogle Scholar
  92. Millard, P., M. Sommerkorn & G. Quen-Aëlle. 2007. Environmental change and carbon limitation in trees: A biochemical, ecophysiological and ecosystem appraisal. New Phytologist 175: 11–28.PubMedCrossRefGoogle Scholar
  93. Michalet, R. 2006. Is facilitation in arid environments the result of direct or complex interactions? New Phytologist 169: 3–6.PubMedCrossRefGoogle Scholar
  94. Mori, A. S., E. Mizumachi & D. G. Sprugel. 2008. Morphological acclimation to understory environments in Abies amabilis, a shade- and snow-tolerant conifer species of the Cascade Mountains, Washington, USA. Tree Physiology 28: 815–824PubMedGoogle Scholar
  95. Nicolussi, K., S. Bortenschlager & C. Körner 1995. Increase in tree-ring width in subalpine Pinus cembra from the central Alps that may be CO2-related. Trees 9: 181–189.CrossRefGoogle Scholar
  96. Niklas, K. J. 2007. Maximum plant height and the biophysical factors that limit it. Tree Physiology 27: 433–440.PubMedGoogle Scholar
  97. ——— & H-C. Spatz. 2006. Allometric theory and the mechanical stability of large trees: Proof and conjecture. American Journal of Botany 93: 824–828.CrossRefGoogle Scholar
  98. Noble, I. R. 1993. A model of response of ecotones to climate change. Ecological Applications 3: 396–403.CrossRefGoogle Scholar
  99. Osmond, C. B. 2007. Crassulacean acid metabolism: now and then. Progress in Botany 68: 3–32.CrossRefGoogle Scholar
  100. Palacio, S., M. Maestroa & G. Montserrat-Martí. 2005. Seasonal dynamics of non-structural carbohydrates in two species of Mediterranean sub-shrubs with different leaf phenology. Environmental and Experimental Botany 59: 34–42.CrossRefGoogle Scholar
  101. Parmesan, C. 2006. Ecological and evolutionary responses to recent climate change. Annual Review of Ecology, Evolution, and Systematics 37: 637–669.CrossRefGoogle Scholar
  102. Paulsen, J., U. M. Weber & C. Körner. 2000. Tree growth near tree line: Abrupt or gradual reduction with altitude? Artic, Antarctic, and Alpine Research 32: 14–20.CrossRefGoogle Scholar
  103. Rathgeber, C., J. Guiot & J. J. Eduard. 2000. Utilisation d’un modèl biogéochimique en dendroécologie. Application au pin Cembro. Comminications de Recherche, Academie des Sciences Paris 323: 489–497.Google Scholar
  104. Raven, J. A. 2002. Selection pressures on stomatal evolution. New Phytologist 153: 371–386.CrossRefGoogle Scholar
  105. Reinhardt, K. & W. K. Smith. 2007. Leaf gas exchange of understory spruce-fir saplings in relict cloud forests, southern Appalachian Mountains, USA. Tree Physiology 28: 113–122.Google Scholar
  106. Risser, P. G. 1995. The status of the science of examining ecotones. Bioscience 45: 318–325.CrossRefGoogle Scholar
  107. Sarmiento, F. O. & L. M. Frolich. 2002. Andean cloud forest tree lines: Naturalness, agriculture and the human dimension. Mountain Research and Development 22: 278–287.CrossRefGoogle Scholar
  108. Seppä, H., M. Nyman, A. Korhola & J. Weckström. 2002. Changes of tree lines and alpine vegetation in relation to post-glacial climate dynamics in northern Fennoscandia based on pollen and chironomid records. Journal of Quaternary Science 17: 287–301.CrossRefGoogle Scholar
  109. Sharkey, T. D., I. Terashima, A. Standish & S. E. Weise. 2004. CO2 processing from the chloroplast to the leaf. Pages 171–206 in W. K. Smith, T. C. Vogelmann, C. Critchley, (eds.), Photosynthetic adaptation from the chloroplast to the landscape. Ecological studies 178. Springer, New York.Google Scholar
  110. Shi, P., C. Körner & G. Hoch. 2006. End-of-season carbon supply status of woody species near the tree line in western China. Basic and Applied Ecology 7: 370–377.CrossRefGoogle Scholar
  111. ———, ——— & ———. 2008. A test of the growth-limitation theory for alpine tree line formation in evergreen and deciduous taxa of the eastern Himalayas. Functional Ecology 22: 213–220.CrossRefGoogle Scholar
  112. Shugart, H. H., N. H. F. French, E. S. Kasischke, J. J. Slawski, C. W. Dull, R. A. Shuchman & J. Mwangi. 2001. Detection of vegetation change using reconnaissance imagery. Global Change Biology 7: 247–252.CrossRefGoogle Scholar
  113. Slatyer, R. O. & I. R. Noble. 1992. Dynamics of montane treelines. Pages 360–378 in A. Hansen, D. Di Castri (eds.), Landscape boundaries: consequences for biotic diversity and ecological flows. Ecological Studies 92. Springer, New York.Google Scholar
  114. Smith, W. K. & C. A. Brewer. 1994. The adaptive importance of shoot and crown architecture in conifer trees. American Naturalist 143: 528–532.CrossRefGoogle Scholar
  115. ——— & G. A. Carter. 1988. Shoot structural effects of needle temperature and photosynthesis in conifers. American Journal of Botany 75: 496–500.CrossRefGoogle Scholar
  116. ——— & R. A. Donahue. 1991. Simulated influence of altitude on photosynthetic CO2 uptake potential in plants. Plant, Cell & Environment 14: 133–136.CrossRefGoogle Scholar
  117. ——— & G. N. Geller. 1981. Leaf and environmental parameters influencing transpiration: Theory and field measurements. Oecologia 46: 308–314.Google Scholar
  118. ——— & N. M. Hughes. 2008. Progress in understanding plant form and photosynthetic function. Castanea, in press.Google Scholar
  119. ——— & D. M. Johnson. 2008. Biophysical effects of altitude on plant gas exchange. In: Biophysical Plant Ecology: Perspectives and Trends. University of California Press, Los Angeles.Google Scholar
  120. ——— & A. K. Knapp. 1990. Ecophysiology of high elevation forests. Pages 87–142 in C. B. Osmond, L. Pitelka (eds.), Plant biology of the Great Basin and range. Springer, London.Google Scholar
  121. ———, M. J. Germino, T. E. Hancock & D. M. Johnson. 2003. Another perspective on the altitudinal occurrence of alpine tree lines. Tree Physiology 23: 1101–1113.PubMedGoogle Scholar
  122. ———, P. S. Nobel, W. E. Reiners, T. C. Vogelmann & C. Chritchley. 2004. Summary and future perspectives. Pages 3-14in W. K. Smith, T. C. Vogelmann, C. Critchley (eds.), Photosynthetic adaptation from the chloroplast to the landscape. Ecological Studies 178. Springer, New York.Google Scholar
  123. ———, D. M. Johnson & K. A. Reinhardt. 2008. Ecosystems: Alpine forest. in S. E. Jorgensen (ed.), Encyclopedia of ecology. Elsevier, Oxford.Google Scholar
  124. Sperry, J. S. 2000. Hydraulic constraints on plant gas exchange. Agricultural and Forest Meteorology 104: 13–23.CrossRefGoogle Scholar
  125. Springer, C. J. & J. K. Ward. 2007. Flowering time and elevated atmospheric CO2. New Phytologist 76: 243–255.CrossRefGoogle Scholar
  126. Stanhill, G. & S. Cohen. 2001. Global dimming: A review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agricultural and Forest Meteorology 107: 255–278.CrossRefGoogle Scholar
  127. Stockton, C. W. 1984. An alternative hypothesis to direct CO2 fertilization as a cause of increased tree growth during 1850–1980 in central Nevada. Preliminary report, Laboratory of Tree Ring Research. University of Arizona, Tucson, 1–26.Google Scholar
  128. Susiluoto, S., M. Perämäkia, E. Nikinmaaa & F. Berninger. 2007. Effects of sink removal on transpiration at the tree line: Implications for the growth limitation hypothesis. Environmental & Experimental Botany 60: 334–339.CrossRefGoogle Scholar
  129. Sveinbjörnsson, B. 2000. North American and European tree lines: external forces and internal processes controlling position. Ambio 29: 388–395.Google Scholar
  130. Terashima, I., T. Masuzawa, H. Ohba & Y. Yokoi. 1995. Is photosynthesis suppressed at higher elevation due to low CO2 pressure? Ecology 76: 2663–2668.CrossRefGoogle Scholar
  131. Tranquillini, W. 1979. Physiological ecology of the alpine timberline. Ecological Studies 31. Springer, New York. 137 pp.Google Scholar
  132. Troll, C. 1973. The upper timberlines in different climatic zones. Arctic and Alpine Research 5: 3–18.Google Scholar
  133. Walsh, S., G. P. Malanson & D. R. Butler. 1992. Alpine treeline in Glacier National Park, Montana. Pages 167–171 in D. Janelle (ed.), Geographical snapshots of North America. Commemorating the 24th Congress of the International Geographical Union and Assembly. Guilford, New York.Google Scholar
  134. Wang, T., Q. Zhang & K. Ma. 2006. Tree line dynamics in relation to climatic variability in the central Tianshan Mountains, northwestern China. Global Ecology and Biogeography 15: 406–415.CrossRefGoogle Scholar
  135. Ward, J. K., J. Antonovics, R. B. Thomas & B. R. Strain. 2000. Is atmospheric CO2 a selective agent on model C3 annuals. Oecologia 123: 330–341.CrossRefGoogle Scholar
  136. Wardle, P. 1974. Alpine timberlines. Pages 371–402 in J. D. Ives, R. G. Barry (eds.), Arctic and alpine environments. Methuen, London.Google Scholar
  137. Webster, P., J. Holland, G. J. Curry & H. R. Chang. 2005. Changes in tropical cyclone number, duration, and intensity in a warming environment. Science 309: 1844–1846.PubMedCrossRefGoogle Scholar
  138. Weiser, G. 2007a. Current concepts for treelife limitations at the upper treeline. Pages 1–18 in G. Wieser, M. Tuasz (eds.), Trees at their upper limit: Tree life limitations at the alpine tree line. Plant Ecophysiology 5. Springer, Dordrecht.Google Scholar
  139. ———. 2007b. Global change at the upper timberline. Pages 197–209 in G. Wieser, M. Tuasz (eds.), Trees at their upper limit: Tree life limitations at the alpine tree line. Plant Ecophysiology 5, Springer, Dordrecht.Google Scholar
  140. ——— & M. Tuasz. 2007. Synopsis. Pages 219–223 in G. Wieser, M. Tuasz (eds.), Trees at their upper limit: Tree life limitations at the alpine tree line. Plant Ecophysiology 5. Springer, Dordrecht.Google Scholar
  141. Wiegand, T., J. L. Camarero, N. Rüger & E. Gutiérrez. 2006. Abrupt population changes in tree line ecotones along smooth gradients. Journal of Ecology 94: 880–889.CrossRefGoogle Scholar
  142. Williams, P. J. B. 1998. The balance of plankton respiration and photosynthesis in the open oceans. Nature 394: 55–57.CrossRefGoogle Scholar
  143. Williams, J. W. & S. T. Jackson. 2007. Novel climates, no-analog communities, and ecological surprises. Frontiers in Ecology and the Environment 5: 475–482.CrossRefGoogle Scholar
  144. Wolf, A., T. V. Callaghan & K. Larson. 2008. Future changes in vegetation and ecosystem function of the Barents Region. Climatic Change. doi.10.1007/s1058-007-9342-4.Google Scholar
  145. Wullschleger, S. D., T. I. Tschaplinski & R. J. Norby. 2002. Plant water relations at elevated CO2—implications for water-limited environments. Plant, Cell & Environment 25: 319–331.CrossRefGoogle Scholar
  146. Zak, D. R., K. S. Pregitzer, J. S. King & W. E. Holmes. 2000. Elevated atmospheric CO2, fine roots and the response of soil microorganisms: a review and hypothesis. New Phytologist 147: 201–222.CrossRefGoogle Scholar
  147. Zens, M. S. & D. R. Peart. 2003. Dealing with death data: individual hazards, mortality and bias. Trends in Ecology and Evolution 18: 366–373.CrossRefGoogle Scholar
  148. Zvereva, E. L. & M. V. Kozlov. 2004. Facilitative effects of top-canopy plants on four dwarf shrub species in habitats severely disturbed by pollution. Journal of Ecology 92: 288–296.CrossRefGoogle Scholar

Copyright information

© The New York Botanical Garden 2009

Authors and Affiliations

  • William K. Smith
    • 1
  • Matthew J. Germino
    • 2
  • Daniel M. Johnson
    • 3
  • Keith Reinhardt
    • 1
  1. 1.Department of BiologyWake Forest UniversityWinston-SalemUSA
  2. 2.Idaho State University, Biological SciencesPocatelloUSA
  3. 3.USDA Forest Service, Forestry Sciences LaboratoryCorvallisUSA

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