Alpine timberline, as the "ecological transition zone," has long attracted attention of scientists in many fields of study, especially scientists of climatic change in recent years. Many unitary and dibasic fitting models have been developed between timberline and its influencing factors. It has been commonly believed that latitude or temperature is a decisive factor for the altitudinal distribution of timberline, and most of the fitting models involve the relationship between timberline and latitude or temperature. However, these models are usually on regional scale and could not be extended to other regions; on the other hand, hemispherical-scale and continental-scale models usually contain only about 100 timberline data and results in low precision. The present article has collected 516 data points of timberline, and takes latitude, continentality and mass elevation effect as independent variables and timberline elevation as dependent variables to set up a ternary linear regression model. Continentality is calculated using the meteorological data released by WorldClim and mountain base elevation (as alternative factor of the mass elevation effect) is extracted on the basis of SRTM 90-meter resolution elevation data. The results show that the coefficient of determination (R2) of the linear model is as high as 0.904, and that the contribution rate of latitude, continentality and mass elevation effect to timberline elevation is 45.02% (p = 0.000), 6.04% (p = 0.000) and 48.94% (p = 0.000), respectively. This revealed that the influence of mountain mass elevation effect on timberline distribution exceeds that of latitude and continentality put together, and that mass mountain effect is the primary factor in determining the elevation distribution of timberline on continental and hemispherical scale. The contribution rate of the mass elevation effect to the timberlines is, although different in different regions, generally high, e.g., 50.49% (p = 0.000) in North America, 48.73% (p = 0.000) in the eastern Eurasia, and 43.6% (p = 0.000) in the western Eurasia.
[1] Szeicz J M, MacDonald G M. Recent white spruce dynamics at the subarctic alpine treeline of north-western Canada.Jounal of Ecology 1995, 83(5): 873-885.
[2] Dullinger S, Dirnbock T, Grabherr G. Modelling climate change-driven treeline shifts: Relative effects of temperatureincrease, dispersal and invasibility. Journal of Ecology, 2004, 92: 241-252.
[3] Malyshev L. Levels of the upper forest boundary in northern Asia. Vegetation, 1993, 109(2): 175-186.
[4] Cogbill C V, White P S. The latitude-elevation relationship for spruce-fir forest line along the Appalachian mountainchain. Vegetation, 1991, 94: 153-175.
[5] Fang Jingyun. Three-dimension distribution of forest zones in East Asia. Acta Geographica Sinica, 1995, 50(2):160-167. [方精云. 东亚地区森林植被带的三维空间分布. 地理学报, 1995, 50(2): 160-167.]
[6] Körner C. A re-assessment of high elevation treeline positions and their explanation. Oecologia, 1998, 115(4): 445-459.
[7] Schickhoff U. The Upper Timberline in the Himalayas, Hindu Kush and Karakorum: A review of geographical andecological aspects. Mountain Ecosystems. 2005, 275-354.
[8] Atalay I. The effects of mountainous areas on biodiversity: A case study from the northern Anatolian mountains and theTaurus mountains. Grazer Schriften der Geographie und Raumforschung, 2006, 41: 17-26.
[9] Daubenmire R. Alpine timberlines in the Americas and their interpretation. Butler University Botanical Studies, 1954,11: 119-135.
[10] Grace J, Allen N J, Wilson C. Climate and the meristem temperatures of plant communities near the tree-line.Oecologia, 1989, 79: 198-204.
[11] Ohsawa M. An interpretation of latitudinal patterns of forest limits in South and East Asian Mountains. Journal ofEcology, 1990, 78(2): 326-339.
[12] Körner C, Paulsen J. A world-wide study of high altitude treeline temperatures. Journal of Biogeography, 2004, 31(5):713-732.
[13] Schroeter C. Das pflanzenleben der Alpen: Eine schilderung der hochgebrigsflora. Verlag von Albert Raustein, Zurich,Switzerland, 1908. [in German]
[14] Tollner. Der Einfluß großer Massenerhebungen auf die Lufttemperatur und die Ursachen der Hebung derVegetationsgrenzen in den inneren Ostalpen. Theoretical and Applied Climatology 1949, 1: 347-372.
[15] Brazel A J, Marcus M G. July temperatures in Kashmir and Ladakh, India: Comparisons of observations andgeneral-circulation model simulations. Mountain Research and Development, 1991, 11(2): 75-86.
[16] Hastenrath S. Certain aspects of the three-dimensional distribution of climate and vegetation belts in the mountains ofC. America and southern Mexico. Geo-ecology of the Mountainous Regions of the Tropical Americas, 1968: 122-130.
[17] Grubb J P. Interpretation of Massenerhebung effect on tropical mountains. Nature, 1971, 1971(229): 44-45.
[18] Leuschner C. Timberline and alpine vegetation on the tropical and warm-temperate oceanic islands of the world:Elevation, structure and floristics. Vegetation, 1996, 123(2): 193-206.
[19] Hall J B. Juniperus excelsa in Africa: A biogeographical study of an afromontane tree. Journal of Biogeography, 1984,11(1): 47-61.
[20] Mccain C M. Elevational gradients in diversity of small mammals. Ecology, 2005, 86(2): 366-372.
[21] Chen L X, Reiter E R, Feng Z Q. The atmospheric heat-source over the Tibetan Plateau - May-August 1979. MonthlyWeather Review, 1985, 113(10): 1771-1790.
[22] Kutzbach J E, Prell W L, Ruddiman W F. Sensitivity of Eurasian climate to surface uplift of the Tibetan Plateau. TheJournal of Geology, 1993, 101(2): 177-190.
[23] Han F, Zhang B P, Yao Y H et al. Mass elevation effect and its contribution to the altitude of snowline in the TibetanPlateau and surrounding areas. Arctic, Antarctic, and Alpine Research, 2011, 43(2): 207-212.
[24] Han Fang, Zhang Baiping, Tan Jing et al. The effect of mountain base elevation on the altitude of timberline in thesoutheastern Eurasia: A study on the quantification of mass elevation effect. Acta Geographica Sinica, 2010, 65(7):781-788. [韩芳, 张百平, 谭靖等. 山体基面高度对欧亚大陆东南部林线分布的影响. 地理学报, 2010, 65(7):781-788.]
[25] Malanson G P, Resler L M, Bader M Y et al. Mountain treelines: A roadmap for research orientation. Arctic, Antarctic,and Alpine Research, 2011, 43(2): 167-177.
[26] Holtmeier F K, Broll G. Sensitivity and response of Northern Hemisphere altitudinal and polar treelines toenvironmental change at landscape and local scales. Global Ecology and Biogeography, 2005, 14(5): 395-410.
[27] Fang Jingyun. Study on the geographic elements affeceting temperature distribution in China. Acta Ecologica Sinica,1992, 12(2): 97-104. [方精云. 地理要素对我国温度分布影响的数量评价. 生态学报, 1992, 12(2): 97-104.]
[28] Miehe G, Miehe S, Vogel J et al. Highest treeline in the Northern Hemisphere found in southern Tibet. MountainResearch and Development, 2007, 27(2): 169-173.
[29] Stanyukovich, K. V. Vegetation of the Mountains of the USSR. Dushanbe: Donim Publishing House, 1973. (in Russian)
[30] Holtmeier F K. Mountain Timberlines Ecology, Patchiness, and Dynamics. Springer Verlag, 2009.
[31] Griggs R F. Timberlines in the northern Rocky Mountains. Ecology, 1938, 19(4): 548-564.
[32] G.Barbour M, Billings W D. North American Terrestrial Vegetation. New York: Cambridge University Press, 1988.
[33] Peng Buzhuo. Some problems of vertical zonation in Mt. Namjagbarwa area. Acta Geographica Sinica, 1986, 41(1):51-58. [彭补拙. 关于西藏南迦巴瓦峰地区垂直自然带的若干问题. 地理学报, 1986, 41(1): 51-58.]
[34] Shreve F. Conditions indirectly affecting vertical distribution on desert mountains. Ecology, 1922, 3(4): 269-274.
[35] Ellenberg H. Leben und kampf an den baumgrenzen der erde. Naturwiss Rundschau, Stuttgart, 1966, 19: 133-139.
[36] Ding Li. Chinese Gazetteer. Shanghai: Shanghai Lexicographical Publishing House, 1990. [丁莉. 中国地名字典. 上海: 上海辞书出版社, 1990.]
[37] Stewart G R. American place-names: A concise and selective dictionary for the continental United States of America.New York: Oxford University Press, 1970.
[38] Hijmans R J, Cameron S E, Parra J L et al. Very high resolution interpolated climate surfaces for global land areas.International Journal Of Climatology, 2005, 25: 1965-1978.
[39] Zhang B P, Wu H Z, Xiao F et al. Integration of data on Chinese mountains into a digital altitudinal belt system.Mountain Research and Development, 2006, 26(2): 163-171.
[40] Tan Jing. Digital intergration and alalysis of mountain altitudinal belt spectra in the Eurasian Continent [D]. Beijing:Institute of Geographic Sciences and Natural Resources Research, CAS, 2009: 127-154. [谭靖. 欧亚大陆山地垂直带谱数字集成与分析[D]. 北京: 中国科学院地理科学与资源研究所, 2009: 127-154.]
[41] Whitmore T C. A vegetation map of Malesia at the scale of 1:5 million. Journal of Biogeography, 1984, 11: 461-471.
[42] Rao G V, Erdogan S. The atmospheric heat source over the Bolivian Plateau for a mean January. Boundary-layerMeteorology, 1989, 46(1): 13-33.
[43] Arno S F, Hammerly R P. Timberline: mountain and arctic forest frontiers. The Mountaineers, 1984.
[44] Cogbill C V, White P S et al. Predicting treeline elevation in the Southern Appalachians. Castanea, 1997, 62(3):137-146.
[45] Messerli B, Winiger M. Climate, environmental change, and resources of the African mountains from the Mediterranean to the Equator. Mountain Research and Development, 1992, 12(4): 315-336.
[46] Flenley J R. Cloud forest, the Massenerhebung effect, and ultraviolet insolation. Ecological Studies, 1995, 110:150-155.
[47] Grubb P J. Control of forest growth and distribution on wet tropical mountains: With special reference to mineralnutrition. Annual Review of Ecology and Systematics, 1977, 8(1): 83-107.
[48] Bader M Y, Ruijten J J A. A topography-based model of forest cover at the alpine treeline in the tropical Andes. J.Biogeogr., 2008, 35: 711-723.
