Krummholz

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Divi Divi Tree ( Caesalpinia coriaria ) in Aruba

As crooked wood or knee wood one naturally describes crooked wood.

Krummholz and cripple forms

The term Krummholz is used in botany for low tree and shrub forms with numerous, sparsely branched, strongly curved or hook-shaped branches, such as for the mountain pine ( Legföhre ) of the Alps or the Lapland pasture of Scandinavia in the Krummholz zone above the tree line; whose growth habit is genetically determined.

In addition, there is the cripple growth or cripple forms , which are caused by extreme climatic conditions. Depending on the altitude, the naturally grown crooked wood is once again forced to become crippled by prolonged snow loads; but also strong winds - for example on many coasts - or steep slopes with corresponding solifluction give woody trees peculiar shapes.

Areas with the same anomalous curvature are a geodynamic pointer . From a forestry point of view, crooked wood is largely worthless today and is classified as a growth defect (crookedness).

Applications

Ribs made of curved wood

Historically, however, suitable crooked wood was a sought-after material, initially for solutions that would otherwise not be technically feasible, and later because the naturally crooked wood with its resilient grain structure could not be replaced in some special applications by crooked components cut from straight wood. It is used for example:

  • since the dawn of human tools manufacturing as a knee-shaped curved piece of wood used as a grave Stock and weapon or the construction of Bronze Age units like Randleistenbeil or plow . Knee wood tools only lost importance when stone and bronze blades were developed to be used on and on .
  • for tool handles ( e.g. spades , scythes ) but up to the modern age.
  • Grown frames that have been carved out of knee wood were once used in shipbuilding .
  • crooked wood is also found regionally in half-timbered construction , for ornamentation.
  • Even in wagons (for wheel tires, water wheels, etc.), sled making (runners) and related crafts, naturally curved woods were used until the 20th century.
  • Alphorns are still made today from spruce trees that have grown on steep slopes and are crooked in the lower trunk area.

Krummholz finally lost its technical use with the invention of wood bending (bentwood), the permanent reshaping of wood treated with steam - known and used in and of itself, for example in cooperage , but not for industrial use until around 1850 further developed ( Thonet furniture ). Today, bentwood is increasingly used again for beams in modern timber construction , even if mostly in the form of laminated beams , natural crooked wood very rarely.

Job title

As krummholz also on who was wandering befindlicher Wagner journeyman called.

literature

  • 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 .
  • Ignaz von Born: Treatises of a private company in Bohemia. Fifth volume, Verlag der Gerlische Buchhandlung, Prague 1782, pp. 130–132.
  • Julius Theodor Christian Ratzeburg: Forest scientific journeys through different areas of Germany. Nicolaische Buchhandlung, Berlin 1842, pp. 369–377.

Web links

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

Individual evidence

  1. Michael Richter (author), Wolf Dieter Blümel et al. (Ed.): Vegetation zones of the earth. 1st edition, Klett-Perthes, Gotha and Stuttgart 2001, ISBN 3-623-00859-1 . P. 306.
  2. Johann Christoph Adelung : Grammatical-critical dictionary of the High German dialect. 2nd edition, Leipzig 1793–1801. Digitized from the University of Trier [1] .