Elven forest

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Elven forest on Mount Kemiri of Gunung Leuser National Park , Sumatra , Indonesia

The Elfenwald (English: Elfin forest , more rarely: Krummholz-Nebelwald ) is a moderately fog- influenced, tropical mountain cloud forest near the tree line , the dwarfism of which is due to frequent winds. Mosses and tree ferns are typical species in the Elven Forest . The "gigantic" ferns and the relatively low trees that occur there give the impression of a fabulous world and create the association with the namesake elves .

Surname

This type of forest was introduced into literature in 1944 by John Stanley Beard under the name elfin woodland because of its fairytale appearance. While Beard later preferred elfin thicket (for example: elf thicket), many authors used elfin forest , which most closely corresponds to the common German term Elfenwald. In the English-language literature there is also the term dwarf forest (for example: dwarf forest). In 1965, Knapp coined the term Krummholz-Nebelwald for this forest , which most clearly combines the two characteristics, but is only rarely used.

classification

Elven forests form the top tier of the tropical cloud forests at high altitudes exposed to strong winds and with little radiation . Their species composition corresponds to the cloud forests; they are differentiated exclusively because of the gnarled, sometimes creeping growth forms and heights of 3 to 5 m. The trees are thickly hung with moss and lichen. In addition, epiphytes such as bromeliads and orchids dominate the vegetation. They form the tropical equivalent of the crooked wood of the temperate zone . The elven forest is followed at higher altitudes by the páramo .

The altitude varies significantly. Due to the mass elevation effect, elven forests are found in the great mountains of South America, the Andes , and in Africa only from around 3000 m, on the Kinabalu in Borneo at around 2800 m, while in isolated mountain areas in the Caribbean they are found below 1000 m.

Characteristics

Despite all the continental differences of the elven forests spread along the tropics, they have numerous things in common:

  • water-saturated soils and reduced root respiration
  • insufficient drainage of the soil
  • strong winds (these create a canopy that looks like a mown meadow.)
  • Nutrient leaching
  • low temperatures
  • frequent cloud cover
  • reduced solar radiation ( e.g. due to the crown of the trees and moss).

The density of individuals and biodiversity decreases dramatically from the lowlands to the elven forest level.

flora

Depending on the region, different trees form the stand. Neotropic occur: Brunellia (family Brunelliaceae ), Bejaria ( Ericaceae ), Clusia ( Clusiaceae ), Gynoxys ( Compositae ), Ilex , Miconia , Rhamnus , Escallonia and Weinmannia ( Cunoniaceae ). Clusia and Araliaceae also grow in Costa Rica . In Africa, the Erica family is predominant and in Malaysia, among others, grow. a. Leptospermum and resin disks . Then there are bamboo and tree ferns such as Cyathea . The almost transparent skin fern plants Hymenophyllum are also typical .

The Puerto Rican wood warbler was first discovered in the elven forest of Puerto Rico and was then given its English name elfin woods warbler .

fauna

Elven forests are home to some animals that only exist in this habitat or that have been discovered here. With an average of 11.4 mm, the smallest frog in the Andes, Noblella pygmaea , was discovered in 2009 by a German-Peruvian research team in the elven forest of the Manú National Park .

The Puerto Rico wood warbler (English: elfin woods warbler ) was discovered in the elven forest of Puerto Rico and was given its English name after this type of forest, as it was assumed at the time that this was its only habitat . Hummingbirds are much more common in the Andes , but these are also endangered species, such as the Antioquia Andean hummingbird , whose occurrence is limited to the elven forest, and the Isabella snow panty, which was discovered in 2005 . The Peruvian owl, one of the world's smallest owls , is also threatened . The Kaiserbekassine was rediscovered due to its limited presence in the field of elves forests until 1972, after she was long considered extinct.

distribution

Elven forests occur in tropical mountain regions around the world. In the eastern Cordillera of Ecuador they are at an altitude between 2700 and 3100 m above sea level. In Puerto Rico there is such a vegetation zone in the El Yunque National Forest in the higher zones. In Africa it is also found below the Páramo level, i.e. below about 3200 to 4000 m. In East Asia there are elven forests on Borneo and Sumatra .

literature

  • Josef H. Reichholf: The Tropical Rainforest: The Ecobiology of the Most Species-Rich Natural Space on Earth . ISBN 978-3596184088 .
  • Thomas Stadtmüller: Terminology - Elfin Woodlands . In: Cloud Forests in the Humid Tropics: A Bibliographic Review. The United Nations University, Centro Agronómico Tropical de Investigación y Enseñanza, 1987, pp. 33-35 ( digitized version ).
  • Douglas F. Stotz et al .: Elfin-Forests (F5) . In: Neotropical Birds: Ecology and Conservation. The University of Chicago Press, 1996, p. 14. ( digitized version )
  • FN Scatena: The management of Luquilli elfin cloud forest ecosystems. Irreversible decisions in a nonsubstitutable ecosystem. In: Lawrence S. Hamilton, James O. Juvik, FN Scatena (eds.): Tropical montane cloud forest. = Ecological studies, Volume 110, Springer, 1995, pp. 296-308 ( digitized version ).

Individual evidence

  1. ↑ Christian Ohlemacher: "Comparative consideration of microclimate, structure and from the xylem sap flow from trees upscaled transpiration of a tropical-montane rainforest and a cloud forest in southeast Ecuador" Diss. Naturwiss. Faculty, University of Hohenheim, p. 174 ( [1] )
  2. ↑ a b Jörg S. Pfadenhauer and Frank A. Klötzli: Vegetation of the earth. Springer Spectrum, Berlin / Heidelberg 2014, ISBN 978-3-642-41949-2 . P. 145.
  3. ^ John Stanley Beard: Climax vegetation in tropical America. In: Ecology , Vol. 25, No. 2, 1944, p. 127.
  4. ^ John Stanley Beard: The classification of tropical American vegetation-types. In: Ecology , Vol. 36, No. 1, pp. 89–100 ( PDF; 556 kB ( Memento of the original from January 9, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice . ). @1@ 2Template: Webachiv / IABot / www.uah.edu
  5. ↑ T. Stadtmüller, p. 33.
  6. ↑ Wolfgang Frey, Rainer Lösch: Geobotany: Plant and Vegetation in Space and Time. Springer Spectrum, 3rd ed., 2014, p. 486.
  7. ↑ T. Stadtmüller, p. 33.
  8. ↑ R. Knapp: The vegetation of North and Central America and the Hawaiian Islands. Jena: G. Fischer, 1965.
  9. ↑ Interactive all-round view, Info No. 3 and 6.
  10. ↑ Heimo Rainer: The palm trees of the Siragebirge and adjacent lowlands in eastern Peru, Austrian Academy of Sciences, Vienna 1995, p. 195 ( [2] )
  11. ↑ a b D. F. Stotz, 1996, p. 14.
  12. ↑ a b Wolfgang Frey, Rainer Lösch: Geobotany: Plant and vegetation in space and time . Springer-Verlag, November 13, 2014, ISBN 978-3-662-45281-3 , p. 486.
  13. ^ Egbert Giles Leigh, Jr .: Tropical Forest Ecology. A View from Barro Colorado Island. Chap .: Why are elfin forests stunted? Oxford University Press, 1999, p. 107 ff. ( Digitized version )
  14. ↑ Mini-frog lives in the elven forest of Peru Die Welt, April 6, 2009.
  15. ↑ Cruz, Alexander and Delannoy, Carlos A .: [ Ecology of the Elfin-woods Warbler ( Dendroica angelae ) II ( Memento from February 25, 2009 in the Internet Archive ) Ecology of the Elfin-woods Warbler ( Dendroica angelae ) II .] In : University of Colorado . September, pp. 152-162.
  16. ^ Erik Hirschfeld, Andy Swash, Robert Still: The World's Rarest Birds . Princeton, 2013, p. 296. ( digitized version )
  17. ↑ Factsheet: Gorgeted Puffleg Eriocnemis isabellae
  18. ^ Erik Hirschfeld, Andy Swash, Robert Still: The World's Rarest Birds . Princeton, 2013, p. 272 ​​( digitized version ).
  19. ↑ John Terborgh, John S. Weske: Rediscovery of the Imperial Snipe in Peru , The Auk No. 89/3, 1972, pp. 497-505, ( PDF ).
  20. ↑ Thorsten Peters: Structure and ecological characteristics of the upper tree line in the Andinen Depression Diss. Naturwiss. Faculty, Friedrich-Alexander-Universität Erlangen-Nürnberg, pp. 28, 42 ( PDF; 19.1 MB )
  21. ^ Dwarf or elfin or cloud forest - in the El Yunque rainforest Puerto Rico

Web links

Commons : Elfenwald  - Collection of images, videos and audio files