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Xylophagous fungi

Fungi are very primitive cellular vegetables which feed on dead elements (saprotrophy) or the substances produced by other animals or vegetables with which they live (parasitism). Fungi can be detected by an abnormal wood colouring, their physical presence on the wood surface (in the form of mycelium or sporocarp), the degradation of the material or the presence of the xylophagous insects which usually accompany them.

The most important factor in relation to the behaviour of this species is its dependence on humidity. In to develop, it requires wood with a minimum humidity level of 18 to 20%. Any wood with a higher level of humidity is prone to attacks from fungi whilst, to the contrary, wood with lower levels is safe from their presence. The optimum level of humidity for fungi attacks is between 35 and 50%.

Types of fungi

Xylophagous fungi may be divided into two main groups: the first is composed of moulds and chromogenic fungi, whilst the second is composed of rot fungi.

Moulds and chromogenic fungi feed on the reserve substances stored in wood and are not responsible for the degradation of the cell wall. Consequently, they do not affect the mechanical properties of wood. Their attacks give rise to a complete change in the wood's colour. A darkening of or the formation of a type of transparent or shaded fluff (cotton-like proliferations) on the surface of the wood indicates their presence. The most characteristic are the blue-stain and the rust fungi. Although they are not dangerous, given their minimum degradation capacity, their presence is indicative of a greater risk, as they are capable of creating the conditions necessary for the development of rot fungi.

The Definitive Solution for cases of blue-stain fungus on wood´s surface is: Red Demon SBS

Rot fungi are responsible for producing the greatest damage to wood. They feed on the components that make up the cell wall, provoking the complete destruction of the cell itself. The hyphae produce chemical products (enzymes) which dissolve the nutrients upon which the wood feeds. The result is a loss in density and resistance, accompanied by a change in colour. The initial stages of an attack are difficult to recognise, given thatthe hyphae remain hidden in the interior of the wood. As the attack develops, there is an increasing change in the colour of the wood, which in turn begins to lose mass. The initial stage of the process sees the complete destruction of the wood's structure, together with the loss of its mechanical properties.

   

   

    

Wood rotting fungi types

Rots may be classified in accordance with three different types:

Brown-rot, the most serious and dangerous type, is produced by fungi which preferentially feed on cellulose and hemicellulose, leaving a dark brown coloured residue formed mainly of lignin. When the wood dries, the residual material tends to split, forming a small cube- or prism-shaped structure which acts like dust under contact with fingers. The initial attack of such fungi favours subsequent attacks by larval-cycle insects (mainly anobiidae).

White rot is produced by fungi which, preferentially, feed on lignin, and to a lesser degree cellulose. Wood subject to an attack of white rot acquires a bluish tone due to the resultant cellulosic complex (a more or less, rarely uniform, whitish cellulose complex upon which appear white streaks separated by areas of normal wood). The wood in turn acquires a fibrous aspect and, as a result, such attacks are sometimes termed "fibrous rot". White rot generally affects the wood of leafy trees more than that of conifers, due to the former's higher lignin content. In Spanish, it is sometimes referred to as corrosive or "de-lignin" rot.

Soft rot is generated by lower fungi, the hyphae of which develops in the interior of the wood's cell walls and mainly attacks secondary cellulose. Wood subject to an attack by soft rot has a soft or spongy aspect similar to that of green cheese. Soft rot is produced by high degrees of humidity, both in the environment and in the wood itself.

The Definitive Solution for cases of wood rotting fungi is: Red Demon SRF

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