Reaction wood - Citizendia

Reaction wood is formed in response to mechanical stress, and helps to position newly formed parts of the plant in an optimal position. Plants are living Organisms belonging to the kingdom Plantae. Reaction wood forms when a woody plant part is subjected to mechanical stress. Plants are living Organisms belonging to the kingdom Plantae. This stress may be the result of wind exposure, excess of snow, soil movement, etc. Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. The reaction wood appear as asymmetric growth. The cambium in the affected part of the trunk is more active on one side, leading to thicker growth rings. Branches practically always have reaction wood, since they need support to maintain their horizontal or nearly horizontal position. There are two different types of reaction wood, which represent two different approaches to the same problem by these groups of plants:

In angiosperms reaction wood is called tension wood. Plants are living Organisms belonging to the kingdom Plantae. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group Tension wood forms above the affected part of the plant, pulling it up. It is composed almost entirely of cellulose. Cellulose is an Organic compound with the formula, a Polysaccharide consisting of a linear chain of several hundred to over ten thousand β(1→4

In conifers it is called compression wood. Compression wood forms below the bent part, pushing it up. Compression wood is rich in lignin. Lignin or lignen is a complex Chemical compound most commonly derived from Wood and an integral part of the secondary Cell walls of Plants

As a rule, reaction wood is undesirable in any commercial application, primarily as its mechanical properties are different. Reaction wood is hard, brittle and it breaks the uniformity of timber. It also responds differently to changes in moisture.

See also