Brown rot
The process of cellulose breakdown in woody plants by fungi is called brown rot (also destructive rot) . The physiological basis necessary for brown rot is the possession of cellulase genes for the production of the enzyme cellulase , which enables it to break down cellulose . According to EN 335: 2013 "Durability of wood and wood products", a wood moisture content of more than 20% is usually required for the development of fungi. Macroscopic symptoms of brown rot are primarily the brown coloration of the affected wood, as the brown lignin is largely retained while the light cellulose is destroyed. Typical is a cross-cracked structure, the so-called “ cube break ”, and the associated loss of strength and mass. When the decomposition by brown rot fungi is complete, the remains of the wood can be ground to powder between the fingers.
Brown rot can occur both in the living tree and in the dead, e.g. B. built-in wood. The contrast to the brown rot is the white rot , in which the lignin is used to a greater extent (also by fungi).
Causing fungi, brown rot, for example, the Lärchenporling ( Laricifomes officinalis ), the Rotrandige Baumschwamm ( Fomitopsis pinicola ), the sulphureus ( Laetiporus sulphureus ) or bitter Saftporling ( Amaropostia stiptica ). This wood degradation is an important process for the forest ecosystem. From an economic point of view, the impairment of the mechanical strength and the commercial value of the affected wood (up to complete devaluation) by such brown rot pathogens can be very serious.
In addition to numerous other types of fungus, the real dry rot ( Serpula lacrymans ), the brown cellar sponge ( Coniophora puteana ) and the white pore sponge ( Antrodia vailantii or Antrodia sinuosa ) are particularly important causes of brown rot damage in buildings .
literature
- Tobias Huckfeldt, Olaf Schmidt: House rot and timber fungi. Verlag Rudolf Müller, Cologne 2006, ISBN 3-481-02142-9
- Klaus Kempe: Wood pests. 3. edit u. exp. Edition, Verlag Bauwesen, Berlin 2004, ISBN 3-345-00827-0
- Heinz Butin: Diseases of forest and park trees , 3rd newly worked and extended edition 1996
- Hans-Peter Sutter: Recognizing and combating wood pests on cultural assets. 4th edition, Haupt Verlag, Bern 2002, ISBN 3-258-06443-1
- Uwe Wild: Lexicon of wood protection. BAULINO Verlag, Waldshut 2009, ISBN 978-3-938537-07-7 , 500 pp.
- Schwarze, FWMR, Engels, J., Mattheck, C. (1999). Wood-decomposing fungi in trees - strategies of wood decomposition. Rombach Verlag, Freiburg 245 pp.
