Silver birch

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Silver birch
Silver birch (Betula pendula), illustration: A branch with male catkins, B branch with budding female catkins, 1 + 2 male flowers, 3 stamens (deeply split) 4 female catkins with flowers ready for pollination. 5 + 6 female inflorescences with 3 flowers each 7 nut fruit (with membranous wings) 8 bracts of the nut fruit

Silver birch ( Betula pendula ), illustration:
A branch with male catkins,
B branch with budding female catkins,
1 + 2 male flowers, 3 stamens (deeply split),
4 female catkins with flowers ready for pollination. 5 + 6 female inflorescences with 3 flowers each
7 nut fruit (with membranous wings)
8 bracts of the nut fruit

Systematics
Eurosiden I
Order : Beech-like (Fagales)
Family : Birch family (Betulaceae)
Subfamily : Betuloideae
Genre : Birch trees ( betula )
Type : Silver birch
Scientific name
Betula pendula
Roth
Betula pollen 400x
Hanging birch grove in the Main-Taunus Arboretum , Eschborn

The silver birch ( Betula pendula ) (Syn .: Betula alba , Betula verrucosa ), also called sand birch , white birch or warty birch , is a deciduous deciduous tree from the birch genus ( Betula ). Its slim, elegant growth, its white bark and its delicate spring green make it a spring symbol. In Scandinavia and Russia it has a role in folk customs similar to that of the linden and oak in Germany . Named as the "sand birch", the silver birch became tree of the year in 2000 .

In the Duden and in generally applicable German dictionaries, this tree is spelled according to the German spelling Hanging Birch . However, if one refers to scientifically founded botanical works, the spelling Hänge-Birke has meanwhile been standardized as a German botanical name, cf. Standard list of fern and flowering plants in Germany .

description

Trunk and bark
Hanging birch avenue in the Donauried

The silver birch is usually between 15 and 25 meters high. It reaches a maximum height of 30 meters and a maximum trunk diameter of 0.9 meters. The maximum age is around 150 years. The species has a multilayered crown. The branches are at an acute angle, the ends of the branches hang over. The silver birch has a smooth white bark. This is formed by a surface periderm, which, however, is not active for life. It bursts open and is then replaced by a deep periderm. The oldest layers of the white smooth bark can peel off more or less over a large area or peel off in narrow strips. The white color of the bark is caused by the deposit of betulin , which completely reflects the light, making the bark appear white. The white colored bark is interpreted as a protective mechanism against bark burn (damage to the bark from intense sunlight), especially in winter.

The silver birch forms a not very deep, but dense heart-root system. The alternate , stalked leaves are 4 to 7 centimeters long and arranged in a spiral. They are triangular to diamond-shaped, with a long tip, their edge is double-sawn.

The silver birch is monoecious. Female and male flowers are separated in pendulous catkins on a plant. Flowering time is from April to May and the seeds ripen in August to September. The fruits are about 3 millimeters long, thin-skinned, winged nuts. The light fruits are spread by the wind and the seeds germinate immediately if there is sufficient moisture.

The number of chromosomes is 2n = 28.

Distribution and ecology

Silver birch trees with autumn leaves

The silver birch is a species of light tree . In Central Europe it is the most important pioneer tree species that was the first to colonize fallow, rubble and bare areas. It is undemanding to the soil, but because of the competition from other tree species it grows mainly on acidic soils; it avoids pure limestone soils, but occurs on gypsum. It grows mostly in dry locations, but has a high water consumption. While young birch trees always need a lot of water, old trees can adapt to very dry locations. However, if a previously damp tree is suddenly dried out, it will die. Because of its undemanding nature, the silver birch can also be found on bog soils and in other extreme locations, to which it is displaced due to its weak competition. It avoids heat and is moderately frost hardy, its photosynthesis optimum is below 20 ° C and it is adapted to short vegetation periods with its early leaves. On heavily wet soils it is replaced by the downy birch , with which it also forms hybrids ( Betula × aurata Borkh. ), But these are sterile.

The main occurrence is in the boreal mixed coniferous forests of Siberia and Scandinavia on nutrient-poor, dry sandy soils with pine and oak . The silver birch is found all over Europe , with the exception of northern Scandinavia, in North America and Asia . Their distribution area extends in the east to the Yenisei , Altai Mountains , the Caucasus and northern Persia . In the southern Alps it rises to 1900  m .

The silver birch comes in many forest communities as a pioneer species after disturbances such. B. storm damage or deforestation , but is usually quickly displaced by more competitive species. The birch-oak forest is a forest community with a permanently higher birch participation , less often it is involved in natural pine forests on sand such as the white moss- pine forest . Since birch trees are hardly bitten by roe deer compared to other deciduous tree species, they can also be found in other forest communities, especially on areas with high game densities. As a pioneer tree species, it occurs preferentially in the reforestation of open forms of vegetation such as heather (together with the Scots pine ). Here it is not so strongly bound to acidic locations and occurs e.g. B. regularly together with the Salweide on rubble. It thrives in pre-forest communities of the Quercion roboris association, the Luzulo-Fagenion sub-association or as a pioneer tree in associations of the Nardo-Callunetea class.

Silver birch trees are not capable of sticking and vegetative reproduction . The very light, airworthy fruits ("wing nuts") enable it to reproduce rapidly , with around 450 fruits per catkin. The fruits ripen in midsummer and are scattered in winter, they germinate in the following spring. Birch trees can start to bear fruit at the age of 5.

The silver birch has developed an aggressive technique to assert itself in the competition for sunlight against other tree species: The limp, hanging twigs, which look like sandpaper due to the cork nipple trimmings, constantly and effectively grind real aisles into the treetops of closely adjacent trees of other species when exposed to the wind .

Systematics

The silver birch ( Betula pendula ) is a kind of the genus of birch ( Betula ) in the family of birch family (Betulaceae). There it is assigned with the alders ( Alnus ) to the subfamily Betuloideae (birch family in the narrower sense). In the birch genus, it is combined with 22 other species of the Albae RGL section . in the subgenus Betula RGL. assigned.

One can distinguish the following subspecies:

  • Betula pendula subsp. mandshurica (rule) Ashburner & McAll. (Syn .: Betula alba subsp. Mandshurica rule ): It occurs from Siberia to Japan and from Alaska to Canada.
  • Seeds and seedlings from a pile of firewood
    Betula pendula subsp. pendula : It occurs from Europe to Siberia and to Iran and Morocco.
  • Betula pendula subsp. szechuanica (CKSchneid.) Ashburner & McAll. : It occurs from southeastern Tibet to the Chinese provinces of Yunnan , Sichuan , Gansu and Qinghai .

Several varieties of the silver birch have been described in older literature (H. Winkler: Betulaceae , in A. Engler: Das Pflanzenreich , 1904):

  • Betula alba f. vulgaris rule : According to R. Govaerts, it belongs to Betula pendula Roth subsp. pendula .
  • Betula pendula var. Oycowiensis (Besser) Dippel with bush-shaped representatives in the valleys of Ojcow in Galicia and the northeast of Hungary
  • Betula alba var. Arbuscula frieze from Dalarna and Uppsala in Sweden. According to R. Govaerts, it belongs to Betula pendula Roth subsp. pendula .
  • Betula pendula var. Obscura (Kotula ex Fiek) Olšavská from the Beskids , the Vistula lowlands and Silesia : According to R. Govaerts, it is a synonym of Betula × aurata Borkh.

In more recent literature, mostly only the variety Betula pendula var. Oycowiensis is given.

use

Importance as timber

Silver birch in the form of a leaf drug (Betulae folium)

The silver birch is a sapwood tree , with age an optional core is sometimes formed. The wood color is white to reddish yellow. The medium-weight wood with a bulk density of 0.61 g / cm³ is soft, but tough and elastic. It can be worked well, but it is difficult to split. The durability is low outdoors. The birch wood is used for furniture and interior design, chipboard, plywood, fiberboard and cellulose are made from it. Valuable veneers are made from different types of grain . The silver birch provides excellent firewood that burns even when green due to its high terpene content . The brushwood is for broom used and in the Finnish sauna for knocking off the skin.

Use in phytotherapy

In phytotherapy (herbal medicine), components of the sand birch are also used, mainly leaves, buds and bark. In the spring a bleeding sap is obtained by drilling into the trunks, from which hair tonic and birch wine are made. Birch tar can be made from the bark , which is used as Pix Betulinae against skin diseases and as Russian oil to treat leather. Further distillation produces birch pitch , which served as a universally applicable adhesive in earlier times (from the Paleolithic to the Middle Ages).

The bark of the birch tree contains terpenes as therapeutically effective components , which are particularly important anti-inflammatory agents and have anti- tumor and antiviral effects, such as betulin , betulinic acid and lupeol.

The blood-purifying and diuretic (urinary) effect has been known for centuries. In addition, gastroprotective effects could also be demonstrated. Puff teas are used for kidney gravel , kidney and bladder stones and other kidney and bladder diseases, and internal use of birch sap is also described. Traditionally, the sand birch is also used for arthritis , excess cholesterol , gout or hyperuricemia , skin and hair problems (tars from the bark and birch sap), rheumatism , perspiration and dropsy ( edema ). The bile is to be promoted. Side effects are not known. Edema as a result of impaired heart or kidney activity is a contraindication . The inhibitory effect on the activity and proliferation of lymphocytes found in the experiment could at least partially explain the observed effect of Betula pendula in autoimmune diseases such as rheumatoid arthritis.

Slight anti-inflammatory, analgesic and antimicrobial effects have also been described for birch sap, which is common in certain areas.

Meaning as an ornamental tree

There are numerous garden forms of the silver birch, such as the weeping birch ('Youngii'), the blood birch (Betula pendula Roth , cultivar 'Purpurea') and the slit-leaved birch ( Trost's Dwarf ) as well as the Örnas birch.

fauna

The birch species belong to the native tree species with a particularly large number of invertebrate species adapted to them, whereby the differences between the silver birch and the downy birch are obviously small. Brändle and Brandl give 499 phytophagous species on birch in Germany, including 106 beetles, 140 large and 105 small butterfly species. 133 species are more or less specialized in birch trees. A specialized beetle species is z. B. the birch leaf roller ( Deporaus betulae , Rhynchitidae), which transforms the front part of the leaf blade into an artistic, bag-shaped “packet” in which it lays its eggs. A striking specialized species is the great birch sawfly . The birch bug is also found on other deciduous trees, but is particularly common on birch. This species can occasionally be a nuisance to humans during mass flights in autumn. Bird species with a certain (but by no means exclusive) attachment to the birch are siskins and polar siskins .

Astronym

The asteroid (8644) Betulapendula was named after the silver birch on April 2, 1999.

supporting documents

Individual evidence

  1. ↑ Böhlmann, p. 48.
  2. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 , p. 313.
  3. ↑ LWF Report No. 28 (PDF) , accessed on December 13, 2015
  4. ↑ Betula pendula. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, accessed October 15, 2011 .
  5. ^ VL Komarov: Flora of the USSR . tape 5 . Koenigstein, 1985 (translated into English from Russian, quoted from Schütt et al.: Enzyklopädie der Laubbäume. P. 130).
  6. ↑ a b c d e f g Rafaël Govaerts (Ed.): Betula - World Checklist of Selected Plant Families of the Royal Botanic Gardens, Kew. Last accessed on January 11, 2017.
  7. ↑ Schütt et al: Encyclopedia of the deciduous trees. P. 130.
  8. ↑ E. Kovac Besovic, K. Durić, Z. Kalodera, E. Sofić: Identification and isolation of pharmacologically active triterpenes in Betuale cortex, Betula pendula Roth, Betulaceae.. In: Bosn J Basic Med Sci. 9 (1), Feb 2009, pp. 31-38.
  9. ↑ C. Yamaguchi, Y. In, S. Wada, T. Yamada, H. Tokuda, R. Tanaka: Cancer chemopreventive activity of oleanane-type triterpenoids from the stem bark of Betula ermanii. In: Chem Biodivers. 6 (7), Jul 2009, pp. 1093-1100.
  10. ↑ MP Germanò, F. Cacciola, P. Donato, P. Dugo, G. Certo, V. D'Angelo, L. Mondello, A. Rapisarda: Betula pendula Roth leaves: gastroprotective effects of an HPLC fingerprinted methanolic extract. In: Natural Product Research . Volume 27, number 17, 2013, ISSN  1478-6427 , pp. 1569-1575, doi: 10.1080 / 14786419.2012.740036 . PMID 23163340 .
  11. ↑ University of Marburg: Crop database ( memento of the original from April 13, 2014 in the Internet Archive ) Info: The archive link was 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 / cgi-host.uni-marburg.de
  12. ↑ C. Gründemann, CW Gruber, A. Hertrampf, M. Zehl, B. Kopp, R. Huber: An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes. In: Journal of Ethnopharmacology . Volume 136, Number 3, July 2011, ISSN  1872-7573 , pp. 444-451, doi: 10.1016 / j.jep.2011.05.018 . PMID 21619918 .
  13. ^ W. Klinger, R. Hirschelmann, J. Süss: Birch sap and birch leaves extract: screening for antimicrobial, phagocytosis-influencing, antiphlogistic and antipyretic activity. In: The Pharmacy . Volume 44, Number 8, August 1989, ISSN  0031-7144 , pp. 558-560. PMID 2594828 .
  14. ↑ The house tree. ( Memento from September 6, 2012 in the web archive archive.today ) In: Family home and garden.
  15. ↑ derkleinegarten.de: planting smaller birch trees
  16. ↑ Landesarboretum database - University of Hohenheim ( Memento of the original from April 20, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.uni-hohenheim.de
  17. ↑ Biology University of Ulm: Betula pendula Roth 'Purpurea'
  18. ↑ Betula pendula 'Consolation Dwarf'. ( Memento of August 2, 2012 in the web archive archive.today ) on: ibro.pl
  19. ↑ Slit-leaved birch - Betula pendula 'Dalecarelica'
  20. ↑ Martin Brändle, Roland Brandl: Species richness of insects and mites on trees: expanding Southwood. In: Journal of Animal Ecology. 70, 2001, pp. 491-504.

literature

  • Schütt, Weisgerber, Schuck, Lang, Stimm, Roloff: Encyclopedia of Deciduous Trees . Nikol, Hamburg 2006, ISBN 3-937872-39-6 , pp. 125-139 .
  • Horst Barthels: Wood science. Ulmer, Stuttgart 1993, ISBN 3-8252-1720-5 .
  • Heinz Ellenberg : Vegetation of Central Europe with the Alps from an ecological, dynamic and historical perspective. 5th, heavily changed and improved edition. Ulmer, Stuttgart 1996, ISBN 3-8001-2696-6 .
  • Dietrich Böhlmann: Why trees don't grow into the sky - An introduction to the life of our trees. Quelle & Meyer Verlag, Wiebelsheim 2009, ISBN 978-3-494-01420-3 .
  • Christian Wild (editor) among others: The sand birch - the birches. Conference on the Tree of the Year 2000 . (= Reports from the Bavarian State Institute for Forests and Forestry. No. 28). Published by the Bavarian State Institute for Forests and Forestry (LWF). LWF, Freising 2000.
  • Armin König: About some methods of breeding selection in the sand birch (Betula pendula Roth) . Dissertation . Göttingen 1985.

Web links

Commons : Silver birch ( Betula pendula )  - Album with pictures, videos and audio files