Dynamics of alpine treelines: positive feedbacks and global, regional and local controls

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  • ABSTRACT

    Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.


  • KEYWORD

    alpine treeline , alternative stable state theory , global factor , positive feedbacks , regional and local factor

  • 1. Alftine KJ, Malanson GP 2004 Directional positive feedback and pattern at an alpine tree line [J Veg Sci] Vol.15 P.3-12 google doi
  • 2. Anadon-Rosell A, Rixen C, Cherubini P, Wipf S, Hagedorn F, Dawes MA 2014 Growth and phenology of three dwarf shrub species in a six-year soil warming experiment at the Alpine treeline [PLoS ONE] Vol.9 P.e100577 google doi
  • 3. Aulitzky H 1961 Die Bodentemperaturen in der Kampfzone oberhalb der Waldgrenze und imsubalpinen Zirben- Larchenwald [Mitt Forstl Bund Mariabrunn] Vol.59 P.153-208 google
  • 4. Autio J 2006 Environmental Factors Controlling the Position of the Actual Timberline and Treeline on the Fells of Finnish Lapland google
  • 5. Autio J, Colpaert A 2005 The impact of elevation, topography and snow load damage of trees on the position of the actual timberline on the fells in central Finnish Lapland [Fennia] Vol.183 P.15-36 google
  • 6. Bader MY 2007 Tropical Alpine Treelines: how ecological processes control vegetation patterning and dynamics. PhD Dissertation google
  • 7. Bader MY, Rietkerk M, Bregt AK 2008 A simple spatial model exploring positive feedbacks at tropical alpine treelines [Arct Antarct Alp Res] Vol.40 P.269-278 google doi
  • 8. Bader MY, Ruijten JJA 2008 A topography-based model of forest cover at the alpine tree line in the tropical Andes [J Biogeogr] Vol.35 P.711-723 google doi
  • 9. Baig MN, Tranquillini W 1980 The effects of wind and temperature on cuticular transpiration of Picea abies and Pinus cembra and their significance in dessication damage at the alpine treeline [Oecologia] Vol.47 P.252-256 google doi
  • 10. Bale JS, Masters GJ, Hodkinson ID, Awmack C, Bezemer TM, Brown VK, Butterfield J, Buse A, Coulson JC, Farrar J, Good JEG, Harrington R, Hartley S, Jones TH, Lindroth RL, Press MC, Symrnioudis I, Watt AD, Whittaker JB 2002 Herbivory in global climate change research: direct effects of rising temperature on insect herbivores [Glob Change Biol] Vol.8 P.1-16 google doi
  • 11. Ball MC, Egerton JJG, Leuning R, Cunningham RB, Dunne P 1997 Microclimate above grass adversely affects spring growth of seedling snow gum (Eucalyptus pauciflora) [Plant Cell Environ] Vol.20 P.155-166 google doi
  • 12. Barbeito I, Dawes MA, Rixen C, Senn J, Bebi P 2012 Factors driving mortality and growth at treeline: a 30-year experiment of 92000 conifers [Ecology] Vol.93 P.389-401 google doi
  • 13. Batllori E, Camarero JJ, Ninot JM, Gutierrez E 2009 Implications and potential responses to climate warming [Glob Ecol Biogeogr] Vol.18 P.460-472 google doi
  • 14. Batllori E, Gutierrez E 2008 Regional treeline dynamics in response to global change in the Pyrenees [J Ecol] Vol.96 P.1275-1288 google doi
  • 15. Bebi P, Kulakowski D, Rixen C 2009 Snow avalanche disturbances in forest ecosystems-State of research and implications for management [For Ecol Manage] Vol.257 P.1883-1892 google doi
  • 16. Bekker MF 2005 Positive feedback between tree establishment and patterns of subalpine forest advancement, Glacier National Park, Montana, USA [Arct Antarc Alp Res] Vol.37 P.97-107 google doi
  • 17. Berdanier AB 2010 Global treeline position [Nat Educ Knowl] Vol.3 P.11 google
  • 18. Black RA, Bliss LC 1980 eproductive ecology of Picea mariana (Mill.) BSP., at the tree line near Inuvik, Northwest Territories, Canada [Ecol Monogr] Vol.50 P.331-354 google doi
  • 19. Bolli J, Rigling A, Bugmann H 2007 Regeneration dynamics of Norway spruce (Picea abies L.) on a subalpine meadow near the treeline in Sedrun, Kt. Graubunden, Switzerland [Silva Fenn] Vol.41 P.55-70 google
  • 20. Brown CD 2010 Tree-line dynamics: adding fire to climate change prediction [Arctic] Vol.63 P.488-492 google
  • 21. Brown DG 1994 Comparison of vegetation-topography relationships at the alpine treeline ecotone [Phys Geogr] Vol.15 P.125-145 google
  • 22. Brown DG 1994 Predicting vegetation types at treeline using topography and biophysical disturbance variables [J Veg Sci] Vol.5 P.641-656 google doi
  • 23. Butler DR, Hill C, Malanson GP, Cairns DM 1994 Stability of alpine treeline in Glacier National Park, Montana, USA [Phytocoenologia] Vol.22 P.485-500 google doi
  • 24. Butler DR, Malanson GP, Walsh SJ, Fagre DB 2007 Influences of geomorphology and geology on alpine treeline in the American West - more important than climatic influences? [Phys Geogr] Vol.28 P.434-450 google doi
  • 25. Cairns DM 1999 Multi-scale analysis of soil nutrients at alpine treeline in Glacier National Park, Montana [Phys Geogr] Vol.20 P.256-271 google
  • 26. Cairns DM, Malanson GP 1998 Environmental variables influencing the carbon balance at the alpine treeline: a modeling approach [J Veg Sci] Vol.9 P.679-692 google doi
  • 27. Cairns DM, Moen J 2004 Herbivory influences tree lines [J Ecol] Vol.92 P.1019-1024 google doi
  • 28. Camarero JJ, Gutierrez E 2004 Pace and pattern of recent treeline dynamics: response of ecotones to climatic variability in the Spanish Pyrenees [Clim Chang] Vol.63 P.181-200 google doi
  • 29. Carlson BZ, Randin CF, Boulangeat I, Lavergne S, Thuiller W, Choler P 2013 Working toward integrated models of alpine plant distribution [Alp Bot] Vol.123 P.41-53 google doi
  • 30. Case BS, Duncan RP 2014 A novel framework for disentangling the scale-dependent influences of abiotic factors on alpine treeline position [Ecography] Vol.37 P.838-851 google doi
  • 31. Chang NK, Shim KC, Lee HU, Kang KM, So KH 1998 The theory of boundary distribution of plant and wave character of the timber line on Mt. Paektu [Korean J Ecol] Vol.21 P.491-499 google
  • 32. Chauchard S, Beilhe F, Denis N, Carcaillet C 2010 An increase in the upper tree-limit of silver fir (Abies alba Mill.) in the Alps since the mid-20th century: a land-use change phenomenon [For Ecol Manage] Vol.259 P.1406-1415 google doi
  • 33. Cho DS 1994 Community structure, and size and age distribution of conifers in subalpine Korean Fir (Abies koreana) Forest in Mt. Chiri [Korean J Ecol] Vol.17 P.415-424 google
  • 34. Cochrane PM, Slatyer RO 1988 Water relations of Eucalyptus pauciflora near the alpine tree line in winter [Tree Physiol] Vol.4 P.45-52 google doi
  • 35. Cogbill CV, White PS 1991 The latitude-elevation relationship for spruce-fir forest and treeline along the Appalachian mountain chain [Vegetatio] Vol.94 P.153-175 google doi
  • 36. Cuevas JG 2000 Tree recruitment at the Nothofagus pumilio alpine timberline in Tierra del Fuego, Chile [J Ecol] Vol.88 P.840-855 google doi
  • 37. Cullen LE, Stewart GH, Duncan RP, Palmer JG 2001 Disturbance and climate warming influences on New Zealand Nothofagus tree-line population dynamics [J Ecol] Vol.89 P.1061-1071 google doi
  • 38. Daly C, Shankman D 1985 Seedling establishment by conifers above the tree limit on Niwot Ridge, Front Range, Colorado, USA [Arct Alp Res] Vol.17 P.389-400 google doi
  • 39. Danby RK, Hik DS 2007 Variability, contingency and rapid change in recent subarctic alpine tree line dynamics [J Ecol] Vol.95 P.352-363 google doi
  • 40. Dang H, Zhang K, Zhang Y, Tan S, Jiang M, Zhang Q 2009 Treeline dynamics in relation to climatic variability in the Shennongjia Mountains, Central China [Can J For Res] Vol.39 P.1848-1858 google doi
  • 41. Daniels LD, Veblen TT 2003 Regional and local effects of disturbance and climate on altitudinal treelines in northern Patagonia [J Veg Sci] Vol.14 P.733-742 google doi
  • 42. Devi N, Hagedorn F, Moiseev P, Bugmann H, Shiyatov S, Mazepa V, Rigling A 2008 Expanding forests and changing growth forms in Siberian larch at the Polar Urals treeline during the 20th century [Glob Change Biol] Vol.14 P.1581-1591 google doi
  • 43. Diaz-Varela RA, Colombo R, Meroni M, Calvo-Iglesias MS, Buffoni A, Tagliaferri A 2010 Spatio-temporal analysis of alpine ecotones: a spatial explicit model targeting altitudinal vegetation shifts [Ecol Model] Vol.221 P.621-633 google doi
  • 44. Dullinger S, Dirnbock T, Grabherr G 2004 Modelling climate change-driven treeline shifts: relative effects of temperature increase, dispersal and invisibility [J Ecol] Vol.92 P.241-252 google doi
  • 45. Fajardo A, Piper FI, Cavieres LA 2011 Distinguishing local from global climate influences in the variation of carbon status with altitude in a tree line species [Glob Ecol Biogeogr] Vol.20 P.307-318 google doi
  • 46. Fajardo A, Piper FI, Pfund L, Korner C, Hoch G 2012 Variation of mobile carbon reserves in trees at the alpine treeline ecotone is under environmental control [New Phytol] Vol.195 P.794-802 google doi
  • 47. Feeley KJ, Silman MR, Bush MB, Farfan W, Cabrera KG, Malhi Y, Meir P, Revilla NS, Quisiyupanqui MNR, Saatchi S 2011 Upslope migration of Andean trees [J Biogeogr] Vol.38 P.783-791 google doi
  • 48. Fletcher MS, Wood SW, Haberle SG 2014 A fire driven shift from forest to non-forest: evidence for alternative stable states? [Ecology] Vol.95 P.2504-2513 google doi
  • 49. Gamache I, Payette S 2004 Height growth response of tree line black spruce to recent climate warming across the forest-tundra of eastern Canada [J Ecol] Vol.92 P.835-845 google doi
  • 50. Gehrig-Fasel J, Guisan A, Zimmermann NE 2007 Tree line shifts in the Swiss Alps: climate change or land abandonment? [J Veg Sci] Vol.18 P.571-582 google doi
  • 51. Germino MJ, Smith WK 1999 Sky exposure, crown architecture, and low­temperature photoinhibition in conifer seedlings at alpine treeline [Plant Cell Environ] Vol.22 P.407-415 google doi
  • 52. Germino MJ, Smith WK, Resor AC 2002 Conifer seedling distribution and survival in an alpine-treeline ecotone [Plant Ecol] Vol.162 P.157-168 google doi
  • 53. Gottfried M, Hantel M, Maurer C, Toechterle R, Pauli H, Grabherr G 2011 Coincidence of the alpine-nival ecotone with the summer snowline [Environ Res Lett] Vol.6 P.014013 google doi
  • 54. Gottfried M, Pauli H, Reiter K, Grabherr G 1999 A finescaled predictive model for changes in species distributions patterns of high mountain plants induced by climate warming [Divers Distrib] Vol.5 P.241-252 google doi
  • 55. Grabherr G, Gottfried M, Pauli H 1994 Climate effects on mountain plants [Nature] Vol.369 P.448 google
  • 56. Grace J 1977 Plant Responses to Wind google
  • 57. Grace J 1989 Tree lines [Phil Trans R Soc Lond B] Vol.324 P.233-245 google doi
  • 58. Grace J, Berninger F, Nagy L 2002 Impacts of climate change on the tree line [Ann Bot] Vol.90 P.537-544 google doi
  • 59. Green K 2009 Causes of stability in the alpine treeline in the Snowy Mountains of Australia-a natural experiment [Aust J Bot] Vol.57 P.171-179 google doi
  • 60. Green K, Venn SE 2012 Tree-limit ribbons in the snowy mountains, Australia: characterization and recent seedling establishment [Arct Antarc Alp Res] Vol.44 P.180-187 google doi
  • 61. Guisan A, Theurillat JP 2000 Assessing alpine plant vulnerability to climate change: a modeling perspective [Integr Assess] Vol.1 P.307-320 google doi
  • 62. Gworek JR, Vander Wall SB, Brussard PF 2007 Changes in biotic interactions and climate determine recruitment of Jeffrey pine along an elevation gradient [For Ecol Manage] Vol.239 P.57-68 google doi
  • 63. Hagedorn F, Shiyatov SG, Mazepa VS, Devi NM, Grigor’ev AA, Bartysh AA, Fomin VV, Kapralov DS, Terent’ev M, Bugman H, Rigling A, Moiseev PA 2014 Treeline advances along the Urals mountain range - driven by improved winter conditions? [Glob Change Biol] Vol.20 P.3530-3543 google doi
  • 64. Handa IT, Korner C, Hattenschwiler S 2005 A test of the treeline carbon limitation hypothesis by in situ CO2enrichment and defoliation [Ecology] Vol.86 P.1288-1300 google doi
  • 65. Harsch MA, Bader MY 2011 Treeline form - a potential key to understanding treeline dynamics [Glob Ecol Biogeogr] Vol.20 P.582-596 google doi
  • 66. Harsch MA, Hulme PE, McGlone MS, Duncan RP 2009 Are treelines advancing? A meta-analysis of treeline response to climate warming [Ecol Lett] Vol.12 P.1040-1049 google doi
  • 67. Harvell CD, Mitchell CE, Ward JR, Altizer S, Dobson AP, Ostfeld RS, Samuel MD 2002 Climate warming and disease risks for terrestrial and marine biota [Science] Vol.296 P.2158-2162 google doi
  • 68. Hattenschwiler S, Korner C 1995 Responses to recent climate warming of Pinus sylvestris and Pinus cembra within their montane transition zone in the Swiss Alps [J Veg Sci] Vol.6 P.357-368 google doi
  • 69. Hattenschwiler S, Smith WK 1999 Seedling occurrence in alpine treeline conifers: a case study from the central Rocky Mountains, USA [Acta Oecol] Vol.20 P.219-224 google doi
  • 70. Heikkinen O, Tuovinen M, Autio J 2002 What determines the timberline [Fennia] Vol.180 P.67-74 google
  • 71. Hemstrom MA, Franklin JF 1982 Fire and other disturbances of the forests in Mount Rainier National Park [Quat Res] Vol.18 P.32-51 google doi
  • 72. Herrero A, Zamora R, Castro J, Hodar JA 2011 Limits of pine forest distribution at the treeline: herbivory matters [Plant Ecol] Vol.213 P.459-469 google
  • 73. Hertel D, Scholing D 2011 Below-ground response of Norway spruce to climate conditions at Mt. Brocken (Germany)-A re-assessment of Central Europe’s northernmost treeline [Flora] Vol.206 P.127-135 google doi
  • 74. Hirota M, Holmgren M, Van Nes EH, Scheffer M 2011 Global resilience of tropical forest and savanna to critical transitions [Science] Vol.334 P.232-235 google doi
  • 75. Hoch G, Korner C 2003 The carbon charging of pines at the climatic treeline: a global comparison [Oecologia] Vol.135 P.10-21 google doi
  • 76. Hoch G, Korner C 2005 Growth, demography and carbon relations of Polylepis trees at the world’s highest treeline [Funct Ecol] Vol.19 P.941-951 google doi
  • 77. Hoch G, Korner C 2009 Growth and carbon relations of tree line forming conifers at constant vs. variable low temperatures [J Ecol] Vol.97 P.57-66 google doi
  • 78. Hoch G, Popp M, Korner C 2002 Altitudinal increase of mobile carbon pools in Pinus cembra suggests sink limitation of growth at the Swiss treeline [Oikos] Vol.98 P.361-374 google doi
  • 79. Holtmeier FK 2003 Mountain Timberlines: Ecology, Patchiness and Dynamics google
  • 80. Holtmeier FK, Broll G 2005 Sensitivity and response of northern hemisphere altitudinal and polar treelines to environmental change at landscape and local scales [Glob Ecol Biogeogr] Vol.14 P.395-410 google doi
  • 81. Holtmeier FK, Broll G 2007 Treeline advance - driving processes and adverse factors [Landsc Online] Vol.1 P.1-33 google
  • 82. Holtmeier FK, Broll G 2010 Wind as an ecological agent at treelines in North America, the Alps, and the European Subarctic [Phys Geogr] Vol.31 P.203-233 google doi
  • 83. Ihm BS, Lee JS, Kim JW 2012 Global warming and biodiversity model projections [J Ecol Field Biol] Vol.35 P.157-166 google doi
  • 84. Ihm BS, Lee JS, Kim JW, Kim JH 2007 Relationship between global warming and species richness of vascular plants [J Plant Biol] Vol.50 P.321-324 google doi
  • 85. 2007 Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change google
  • 86. 2013 Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change google
  • 87. Jeffers ES, Bonsall MB, Brooks SJ, Willis KJ 2011 Abrupt environmental changes drive shifts in tree-grass interaction outcomes [J Ecol] Vol.99 P.1063-1070 google doi
  • 88. Jobbagy EG, Jackson RB 2000 Global controls of forest line elevation in the northern and southern hemispheres [Glob Ecol Biogeogr] Vol.9 P.253-268 google doi
  • 89. Johnson DM, Germino MJ, Smith WK 2004 Abiotic factors limiting photosynthesis in Abies lasiocarpa and Picea engelmannii seedlings below and above the alpine timberline [Tree Physiol] Vol.24 P.377-386 google doi
  • 90. Kim JH 2012 Global Warming google
  • 91. Knox KJE, Clarke PJ 2012 Fire severity, feedback effects and resilience to alternative community states in forest assemblages [For Ecol Manage] Vol.265 P.47-54 google doi
  • 92. Kong WS 1999 The vertical distribution of air temperature and thermal amplitude of alpine plants on Mt. Halla, Cheju Island, Korea [J Korean Geo Soc] Vol.34 P.385-393 google
  • 93. Kong WS 2000 Geoecology on the subalpine vegetation and landscape of Mt. Sorak [J Korean Geo Soc] Vol.35 P.177-187 google
  • 94. Kong WS, Watts D 1993 The Plant Geography of Korea with an Emphasis on the Alpine Zones google
  • 95. Korner C 1998 A re-assessment of high-elevation treeline positions and their explanation [Oecologia] Vol.115 P.445-459 google doi
  • 96. Korner C 2003 Carbon limitation in trees [J Ecol] Vol.91 P.4-17 google doi
  • 97. Korner C 2012 Alpine Treelines google
  • 98. Korner C, Paulsen J 2004 A world-wide study of high altitude treeline temperatures [J Biogeogr] Vol.31 P.713-732 google doi
  • 99. Kreyling J, Wana D, Beierkuhnlein C 2010 Potential consequences of climate warming for tropical plant species in high mountains of southern Ethiopia [Divers Distrib] Vol.16 P.593-605 google doi
  • 100. Kullman L 2001 20th century climate warming and treelimit rise in the southern Scandes of Sweden [Ambio] Vol.30 P.72-80 google doi
  • 101. Kullman L 2002 Rapid recent range-margin rise of tree and shrub species in the Swedish Scandes [J Ecol] Vol.90 P.68-77 google doi
  • 102. Kullman L 2005 Wind-conditioned 20th century decline of birch treeline vegetation in the Swedish Scandes [Arctic] Vol.58 P.286-294 google
  • 103. 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 [J Ecol] Vol.95 P.41-52 google doi
  • 104. Kullman L 2010 A richer, greener and smaller alpine world: review and projection of warming-induced plant cover change in the Swedish Scandes [Ambio] Vol.39 P.159-169 google doi
  • 105. Kullman L 2010 One century of treeline change and stability - experiences from the Swedish Scandes [Landsc Online] Vol.17 P.1-31 google
  • 106. Lenoir J, Gegout JC, Marquet PA, de Ruffray P, Brisse H 2008 A significant upward shift in plant species optimum elevation during the 20th century [Science] Vol.320 P.1768-1771 google doi
  • 107. Leonelli G, Pelfini M, di Cella UM 2009 Detecting climatic treelines in the Italian Alps: The influence of geomorphological factors and of human impacts [Phys Geogr] Vol.30 P.338-352 google doi
  • 108. Leonelli G, Pelfini M, di Cella UM, Garavaglia V 2011 Climate warming and the recent treeline shift in the European Alps: the role of geomorphological factors in highaltitude sites [Ambio] Vol.40 P.264-273 google doi
  • 109. Li MH, Xiao WF, Wang SG, Cheng GW, Cherubini P, Cal XH, Liu XL, Wang XD, Zhu WZ 2008 Evidence for carbon gain limitation but not for growth limitation [Tree Physiol] Vol.28 P.1287-1296 google doi
  • 110. Lloyd AH, Fastie CL 2003 Recent changes in treeline forest distribution and structure in interior Alaska [Ecoscience] Vol.10 P.176-185 google
  • 111. MacDonald GM, Kremenetski KV, Beilman DW 2008 Climate change and the northern Russian treeline zone [Phil Trans R Soc B] Vol.363 P.2285-2299 google
  • 112. Macek P, Mackova J, de Bello F 2009 Morphological and ecophysiological traits shaping altitudinal distribution of three Polylepis treeline species in the dry tropical Andes [Acta Oecol] Vol.35 P.778-785 google doi
  • 113. Malanson GP 2001 Complex responses to global change at alpine treeline [Phys Geogr] Vol.22 P.333-342 google
  • 114. Malanson GP, Butler DR, Fagre DB, Walsh SJ, Tomback DF, Daniels LD, Resler LM, Smith WK, Weiss DJ, Peterson DL, Bunn AG, Hiemstra CA, Liptzin D, Bourgeron PS, Shen Z, Millar CI 2007 Alpine treeline of western North America: Linking organism-to-landscape dynamics [Phys Geogr] Vol.28 P.378-396 google doi
  • 115. Malanson GP, Resler LM, Bader MY, Holtmeier FK, Butler DR, Weiss DJ, Daniels LD, Fagre DB 2011 Mountain treelines: a roadmap for research orientation [Arct Antarc Alp Res] Vol.43 P.167-177 google doi
  • 116. Marchand PJ, Chabot BF 1978 Winter water relations of tree-line plant species on Mt. Washington, New Hampshire [Arct Alp Res] Vol.10 P.105-116 google doi
  • 117. Mayer AL, Khalyani AH 2011 Grass trumps trees with fire [Science] Vol.334 P.188-189 google doi
  • 118. Moen J, Aune K, Edenius L, Angerbjorn A 2004 Potential effects of climate change on treeline position in the Swedish mountains [Ecol Soc] Vol.9 P.16 google
  • 119. Moen J, Cairns DM, Lafon CW 2008 Factors structuring the treeline ecotone in Fennoscandia [Plant Ecol Divers] Vol.1 P.77-87 google doi
  • 120. Motta R, Nola P 2001 Growth trends and dynamics in subalpine forest stands in the Varaita Valley (Piedmont, Italy) and their relationships with human activities and global change [J Veg Sci] Vol.12 P.219-230 google doi
  • 121. Murphy BP, Bowman DMJS 2012 What controls the distribution of tropical forest and savanna? [Ecol Lett] Vol.15 P.748-758 google doi
  • 122. Noble IR 1980 Interactions between tussock grass (Poa spp.) and Eucalyptus pauciflora seedlings near treeline in South-Eastern Australia [Oecologia] Vol.45 P.350-353 google doi
  • 123. Noble IR 1993 A model of the responses of ecotones to climate change [Ecol Appl] Vol.3 P.396-403 google doi
  • 124. Odion DC, Moritz MA, DellaSala DA 2010 Alternative community states maintained by fire in the Klamath Mountains, USA [J Ecol] Vol.98 P.96-105 google doi
  • 125. Odland A 2009 Interpretation of altitudinal gradients in South Central Norway based on vascular plants as environmental indicators [Ecol Indic] Vol.9 P.409-421 google doi
  • 126. Pauli H, Gottfried M, Grabherr G 1996 Effects of climate change on mountain ecosystems - upward shifting of alpine plants [World Resource Review] Vol.8 P.382-390 google
  • 127. Payette S, Filion L, Delwaide A, Begin C 1989 Reconstruction of tree-line vegetation response to long-term climate change [Nature] Vol.341 P.429-432 google doi
  • 128. Rada F, Azocar A, Briceno B, Gonzalez J, Garcia-Nunez C 1996 Carbon and water balance in Polylepis sericea, a tropical treeline species [Trees] Vol.10 P.218-222 google
  • 129. Resler LM 2006 Geomorphic controls of spatial pattern and process at alpine treeline [Prof Geogr] Vol.58 P.124-138 google doi
  • 130. Richardson AD, Friedland AJ 2009 A review of the theories to explain Arctic and alpine treelines around the world [J Sustainable For] Vol.28 P.218-242 google
  • 131. Rixen C, Dawes MA, Wipf S, Hagedorn F 2012 Evidence of enhanced freezing damage in treeline plants during six years of CO2 enrichment and soil warming [Oikos] Vol.121 P.1532-1543 google doi
  • 132. Sakai A 1970 Mechanism of desiccation damage of conifers wintering in soil-frozen areas [Ecology] Vol.51 P.657-664 google doi
  • 133. Scheffer M, Carpenter S, Foley JA, Folke C, Walker B 2001 Catastrophic shifts in ecosystems [Nature] Vol.413 P.591-596 google doi
  • 134. Scherrer D, Korner C 2011 Topographically controlled thermal- habitat differentiation buffers alpine plant diversity against climate warming [J Biogeogr] Vol.38 P.406-416 google doi
  • 135. Schulze ED, Mooney HA, Dunn EL 1967 Wintertime photosynthesis of bristlecone pine (Pinus aristata) in White Mountains of California [Ecology] Vol.48 P.1044-1047 google doi
  • 136. Scott AC, Bowman DMJS, Bond WJ, Pyne SJ, Alexander ME 2014 Fire on Earth: An Introduction google
  • 137. Scott PA, Hansell RIC, Erickson WR 1993 Influences of wind and snow on northern tree-line environments at Churchill, Manitoba, Canada [Arctic] Vol.46 P.316-323 google
  • 138. Shankman D, Daly C 1988 Forest regeneration above tree limit depressed by fire in the Colorado Front Range [B Torrey Bot Club] Vol.115 P.272-279 google doi
  • 139. Shi P, Korner C, Hoch G 2006 End of season carbon supply status of woody species near the treeline in western China [Basic Appl Ecol] Vol.7 P.370-377 google doi
  • 140. Shi P, Korner C, Hoch G 2008 A test of the growth-limitation theory for alpine tree line formation in evergreen and deciduous taxa of the eastern Himalayas [Funct Ecol] Vol.22 P.213-220 google doi
  • 141. Singh CP, Panigrahy S, Thapliyal A, Kimothi MM, Soni P, Parihar JS 2012 Monitoring the alpine treeline shift in parts of the Indian Himalayas using remote sensing [Curr Sci] Vol.102 P.559-562 google
  • 142. Smith WK, Germino MJ, Hancock TE, Johnson DM 2003 Another perspective on altitudinal limits of alpine timberlines [Tree Physiol] Vol.23 P.1101-1112 google doi
  • 143. Smith WK, Germino MJ, Johnson DM, Reinhardt K 2009 The altitude of alpine treeline: a bellwether of climate change effects [Bot Rev] Vol.75 P.163-190 google doi
  • 144. Smith-McKenna EK, Malanson GP, Resler LM, Carstensen LW, Prisley SP, Tomback DF 2014 Cascading effects of feedbacks, disease, and climate change on alpine treeline dynamics [Environ Model Softw] Vol.62 P.85-96 google doi
  • 145. Speed JDM, Austrheim G, Hester AJ, Mysterud A 2010 Experimental evidence for herbivore limitation of the treeline [Ecology] Vol.91 P.3414-3420 google doi
  • 146. Staver AC, Archibald S, Levin SA 2011 The global extent and determinants of savanna and forest as alternative biome states [Science] Vol.334 P.230-232 google doi
  • 147. Stevens GC, Fox JF 1991 The causes of treeline [Annu Rev Ecol Syst] Vol.22 P.177-191 google doi
  • 148. Stueve KM, Cerney DL, Rochefort RM, Kurth LL 2009 Postfire tree establishment patterns at the alpine treeline ecotone: Mount Rainier National Park, Washington, USA [J Veg Sci] Vol.20 P.107-120 google doi
  • 149. Susiluoto S, Peramaki M, Nikinmaa E, Berninger F 2007 Effects of sink removal on transpiration at the treeline: implications for the growth limitation hypothesis [Environ Exp Bot] Vol.60 P.334-339 google doi
  • 150. Sveinbjornsson B 2000 North American and European treelines: external forces and internal processes controlling position [Ambio] Vol.29 P.388-395 google doi
  • 151. Sveinbjornsson B, Kauhanen H, Nordell O 1996 Treeline ecology of mountain birch in the Tornetrask area [Ecol Bull] Vol.45 P.65-70 google
  • 152. Szeicz JM, MacDonald GM 1995 Recent white spruce dynamics at the subarctic alpine treeline of north-western Canada [J Ecol] Vol.83 P.873-885 google doi
  • 153. Szerencsits E 2012 Swiss tree lines - a GIS-based approximation [Landsc Online] Vol.28 P.1-18 google
  • 154. Telewski FW, Coutts MP, Grace J 1995 Wind-induced physiological and developmental responses in trees;Wind and Trees P.237-263 google
  • 155. Tomback DF, Resler LM 2007 Invasive pathogens at alpine treeline: complications and concerns [Phys Geogr] Vol.28 P.397-418 google doi
  • 156. Tranquillini W 1979 Tree Existence at High Altitudes with Special References to the European Alps google
  • 157. Wallentin G, Tappeiner U, Strobl J, Tasser E 2008 Understanding alpine tree line dynamics: an individual based model [Ecol Model] Vol.218 P.235-246 google doi
  • 158. Walsh SJ, Butler DR, Allen TR, Malanson GP 1994 Influence of snow patterns and snow avalanches on the alpine treeline ecotone [J Veg Sci] Vol.5 P.657-672 google doi
  • 159. Walsh SJ, Butler DR, Malanson GP, Crews-Meyer KA, Messina JP, Xiao N 2003 Mapping, modeling, and visualization of the influences of geomorphic processes on the alpine treeline ecotone, Glacier National Park, MT, USA [Geomorphology] Vol.53 P.129-145 google doi
  • 160. Walther G 2003 Plants in a warmer world [Perspect Plant Ecol Evol Syst] Vol.6 P.169-185 google doi
  • 161. Walther GR, Beißner S, Burga CA 2005 Trends in the upward shift of alpine plants [J Veg Sci] Vol.16 P.541-548 google doi
  • 162. Wang T, Zhang QB, Ma KP 2006 Treeline dynamics in relation to climatic variability in the central Tianshan Mountains, northwestern China [Global Ecol Biogeogr] Vol.15 P.406-415 google doi
  • 163. Wardle P, Coleman MC 1992 Evidence for rising upper limits of four native New Zealand forest trees [New Zeal J Bot] Vol.30 P.303-314 google doi
  • 164. Warman L, Moles AT 2009 Alternative stable states in Australia's wet tropics: a theoretical framework for the field data and a field-case for the theory [Landsc Ecol] Vol.24 P.1-13 google doi
  • 165. Wieser G, Matyssek R, Luzian R, Zwerger P, Pindur P, Oberhuber W, Gruber A 2009 Effects of atmospheric and climate change at the timberline of the Central European Alps [Ann For Sci] Vol.66 P.402-412 google doi
  • 166. Wilson JB, Agnew ADQ 1992 Positive-feedback Switches in Plant Communities google
  • 167. Wood SW, Bowman DMJS 2012 Alternative stable states and the role of fire-vegetation-soil feedbacks in the temperate wilderness of southwest Tasmania [Landsc Ecol] Vol.27 P.13-28 google doi
  • 168. Wood SW, Murphy BP, Bowman DMJS 2011 Firescape ecology: how topography determines the contrasting distribution of fire and rain forest in the south-west of the Tasmanian Wilderness World Heritage Area [J Biogeogr] Vol.38 P.1807-1820 google doi
  • 169. Xu Z, Hu T, Zhang Y 2012 Effects of experimental warming on phenology, growth and gas exchange of treeline birch (Betula utilis) saplings, Eastern Tibetan Plateau, China [Eur J Forest Res] Vol.131 P.811-819 google doi
  • 170. Zhang YJ, Dai, LM, Pan J 2001 The trend of tree line on the northern slope of Changbai Mountain [J For Res] Vol.12 P.97-100 google doi
  • [Fig. 1.] Treeline region: ideas and concepts mainly according to Heikkinen et al. (2002) and Korner and Paulsen (2004).
    Treeline region: ideas and concepts mainly according to Heikkinen et al. (2002) and Korner and Paulsen (2004).
  • [Table 1.] Global, regional, and local factors, species-specific traits, and positive feedbacks determining treeline positions in high altitude environments
    Global, regional, and local factors, species-specific traits, and positive feedbacks determining treeline positions in high altitude environments
  • [Fig. 2.] Effects of global, regional, and local factors, species-specific traits and positive feedbacks on treeline migration. Double ended arrow indicates a feedback relationship between processes. Adapted from Tranquillini (1979), Smith et al. (2006) and concepts discussed in this paper.
    Effects of global, regional, and local factors, species-specific traits and positive feedbacks on treeline migration. Double ended arrow indicates a feedback relationship between processes. Adapted from Tranquillini (1979), Smith et al. (2006) and concepts discussed in this paper.
  • [Fig. 3.] Model of the combined effects of temperature/resource availability and local/regional stress factors (e.g., freezing temperatures, snow pack, wind or high solar radiation) on canopy cover at the treeline. In two alternative representations of the same model: (a) canopy cover is shown as a function of temperature and resource availability, and (b) canopy cover is shown as a function of local and regional stress factors. Alternative stable states of forest and treeless alpine vegetation exist under the same external environmental conditions (zone of tension: grey area) depending on the frequency and intensity of local and regional stress factors. Abrupt transitions from forest to alpine vegetation or vice versa can occur at threshold temperature/resource conditions or due to disturbance by stress factors. Adapted from Murphy and Bowman (2012) and Malanson et al. (2011).
    Model of the combined effects of temperature/resource availability and local/regional stress factors (e.g., freezing temperatures, snow pack, wind or high solar radiation) on canopy cover at the treeline. In two alternative representations of the same model: (a) canopy cover is shown as a function of temperature and resource availability, and (b) canopy cover is shown as a function of local and regional stress factors. Alternative stable states of forest and treeless alpine vegetation exist under the same external environmental conditions (zone of tension: grey area) depending on the frequency and intensity of local and regional stress factors. Abrupt transitions from forest to alpine vegetation or vice versa can occur at threshold temperature/resource conditions or due to disturbance by stress factors. Adapted from Murphy and Bowman (2012) and Malanson et al. (2011).