Birch facts for kids

Kids Encyclopedia Facts
Birch
Silver birch
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Betulaceae
Genus: Betula
L.

A birch tree is a thinleaved deciduous hardwood tree of the genus Betula. They are in the family Betulaceae, which also includes alders, hazels, and hornbeams.

Betula contains 30 to 60 species of which 11 are on the IUCN 2011 Green List of Threatened Species. They are usually rather short-lived pioneer species widespread in the Northern Hemisphere.

Uses

Birke Multiplex
Birch plywood
Hankasalmi stream
Birch trees near stream in Hankasalmi, Finland
Sügise märgid
Birch tree in autumn

Because of the hardness of birch, it is easier to shape it with power tools, as it is quite difficult to work it with hand tools.

  • Birch wood is fine-grained and pale in colour, often with an attractive satin-like sheen. Ripple figuring may occur, increasing the value of the timber for veneer and furniture-making. The highly decorative Masur (or Karelian) birch, from Betula verrucosa var. carelica, has ripple textures combined with attractive dark streaks and lines.
  • Birch plywood is made from laminations of birch veneer. It is light but strong, and has many other good properties. It's among the strongest and dimensionally most stable plywoods, although it is unsuitable for exterior use. Birch plywood is used to make longboards (skateboard), giving it a strong yet flexible ride. It is also used (often in very thin grades with many laminations) for making model aircraft.
  • Extracts of birch are used for flavoring or leather oil, and in cosmetics such as soap or shampoo. In the past, commercial oil of wintergreen (methyl salicylate) was made from the sweet birch (Betula lenta).
  • Birch-tar or Russian oil extracted from birch bark is thermoplastic and waterproof; it was used as a glue on, for example, arrows, and also for medicinal purposes.
  • Fragrant twigs of silver birch are used in saunas to relax the muscles.
  • Birch is also associated with the feast of Pentecost in Central and Eastern Europe and Siberia, where its branches are used as decoration for churches and homes on this day.
  • Birch leaves are used to make a diuretic tea and extracts for dyes and cosmetics.
  • Ground birch bark, fermented in sea water, is used for seasoning the woolen, hemp or linen sails and hemp rope of traditional Norwegian boats.
  • Birch twigs bound in a bundle, also called birch, were used for birching, a form of corporal punishment.
  • Many Native Americans in the United States prized the birch for its bark, which because of its light weight, flexibility, and the ease with which it could be stripped from fallen trees, was often used for the construction of strong, waterproof but lightweight canoes, bowls, and wigwams.
  • The Hughes H-4 Hercules was made mostly of birch wood, despite its better-known moniker, "The Spruce Goose".
  • Birch plywood was specified by the BBC as the only wood that can be used in making the cabinets of the long-lived LS3/5A loudspeaker.
  • Birch is used as firewood because of its high calorific value per unit weight and unit volume. It burns well, without popping, even when frozen and freshly hewn. The bark will burn very well even when wet because of the oils it contains. With care, it can be split into very thin sheets that will ignite from even the smallest of sparks.
  • Birch sap is a traditional drink in Northern Europe, Siberia, and Northern China. The sap is also bottled and sold commercially. Birch sap can be used to make birch syrup, which is used like maple syrup for pancakes and waffles. Birch wood can be used to smoke foods.
  • Birch seeds are used as leaf litter in miniature terrain models.
  • Birch oil is used in the manufacture of Russia leather, a water-resistant leather.

Cultivation

White-barked birches in particular are cultivated as ornamental trees, largely for their appearance in winter. The Himalayan birch, Betula utilis, especially the variety or subspecies jacquemontii, is among the most widely planted for this purpose. It has been cultivated since the 1870s, and many cultivars are available, including 'Doorenbos', 'Grayswood Ghost' and 'Silver Shadow'; 'Knightshayes' has a slightly weeping habit. Other species with ornamental white bark include Betula ermanii, Betula papyrifera, Betula pendula and Betula raddeana.

Medical

  • Birch bark is high in betulin and betulinic acid, phytochemicals which have potential as pharmaceuticals, and other chemicals which show promise as industrial lubricants.
  • Birch buds are used in folk medicine.
  • Birch bark can be soaked until moist in water, and then formed into a cast for a broken arm.
  • The inner bark of birch can be ingested safely.
  • In northern latitudes, birch is considered to be the most important allergenic tree pollen, with an estimated 15–20% of hay fever sufferers sensitive to birch pollen grains. The major allergen is a protein called Bet v I.

Paper

See also: Birch bark document
Birch bark document 210
A birch bark inscription excavated from Novgorod, circa 1240–1260

Wood pulp made from birch gives relatively long and slender fibres for a hardwood. The thin walls cause the fibre to collapse upon drying, giving a paper with low bulk and low opacity. The birch fibres are, however, easily fibrillated and give about 75% of the tensile strength of softwood. The low opacity makes it suitable for making glassine.

In India, the birch (Sanskrit: भुर्ज, bhurja) holds great historical significance in the culture of North India, where the thin bark coming off in winter was extensively used as writing paper. Birch paper (Sanskrit: भुर्ज पत्र, bhurja patra) is exceptionally durable and was the material used for many ancient Indian texts. The Roman period Vindolanda tablets also use birch as a material on which to write and birch bark was used widely in ancient Russia as note paper (beresta) and for decorative purposes and even making footwear.

Tonewood

Baltic birch is among the most sought-after wood in the manufacture of speaker cabinets. Birch has a natural resonance that peaks in the high and low frequencies, which are also the hardest for speakers to reproduce. This resonance compensates for the roll-off of low and high frequencies in the speakers, and evens the tone. Birch is known for having "natural EQ".

Drums are often made from birch. Prior to the 1970s, it was one of the most popular drum woods. Because of the need for greater volume and midrange clarity, drums were made almost entirely from maple until recently, when advances in live sound reinforcement and drum microphones have allowed the use of birch in high-volume situations. Birch drums have a natural boost in the high and low frequencies, which allows the drums to sound fuller.

Birch wood is sometimes used as a tonewood for semiacoustic and acoustic guitar bodies, and occasionally for solid-body guitar bodies. It is also a common material used in mallets for keyboard percussion.

Images for kids


Birch Facts for Kids. Kiddle Encyclopedia.