Bark

As bark (Latin cortex) are referred to all the tissues outside of the central cylinder in the stem axis and the roots of vascular plants ( Tracheophyta ). When the term bark is used in everyday life, but only a part of the bark of woody plants is usually meant, namely the final fabric, which is called specific periderm or bark.

Construction

In plants without secondary growth or prior to its insertion, the cortex includes the base fabric between the epidermis and the central cylinder of the root or the Kambiumring the stem axis. The bark is usually rich in intercellular spaces and often used to store. Frequently located in the cortex also strengthening tissues such as sclerenchyma and Kollenchymstränge.

In plants with secondary growth from the cambium outward emitted Bast (secondary phloem ) is counted for (secondary) bark. This consists of the sieve tubes with companion cells, bast fibers, and sclereids. Part of this bark is the secondary dermal tissue, the periderm. Colloquially this periderm is equated with the term bark.

Plants with very strong secondary growth in thickness, lots of trees and shrubs form a tertiary degree tissue, the bark, which is referred to in common parlance as a bark. Unlike bark heal injuries to the bark and remain visible for decades ( see picture).

Advent

Bark is obtained in all establishments, debark the logs. In the context of the use of wood fall in Germany every year about 4 million cubic meters of tree bark. Of these, can 1-1.5 million m³ considered technically available. About 140-170 million cubic meters of bark are estimated annually worldwide ( 10% bark content on the use of timber ).

Use characteristics and uses

Dried bark have good insulation properties and an increased in comparison with wood fire resistance. By their content of tannins, they are relatively resistant to microorganisms.

In particular, the outer regions of the bark are used widely use: Your wealth of tannic acid makes them important Gerbmaterialien. To obtain the Gerbrinden the respective trees ( oaks and acacias ) are taken into Lohwäldern. Allow the shoots reach only the age in which they provide the best bark. Many other rinds and beef parts, the Peruvian bark or cinnamon are medicinally (see medicinal plant ) or used as a spice.

The cork tree Amur cork tree and the Asian supply the cork are made from mainly stoppers and cork. The Flaschenkorkproduktion makes up about 70 % of the value of the Korkanbau. In addition, cork is used for the manufacture of floor coverings and insulation materials and a range of other products.

Bark is mainly burned for energy and used as mulch bark ( bark ), next to it is also processed to bark compost as a peat substitute. Mulch bark and bark compost are produced by crushing, screening and, where appropriate composting of tree bark. They are supplied in bulk or in bags to the consumer. Bark can also be incorporated into pellets of energy but reduces their quality. How can cork bark of various species of trees are also used for various material applications. Corresponding approaches such as insulation boards, loose-fill or decorative materials are currently still in development.