Have you seen a fungal bracket like this attached to one of your trees? What you may not realise is that what you can see is only the fruiting body of the fungus, the tip of the iceberg as it were.
What you can’t see is the decayed timber laced with mycelium beneath the bark of the tree. Mycelium are fine white filaments, similar to roots, that form a complex network throughout the timber; actively consuming either the structural lignin (known as white rote) or the cellulose (known as brown rot).
White rot is more common and can sometimes be identified by visible bulges in the trunk or branch where the decay is located. The bulge is reactive growth instigated by the tree to try to balance the loss of structural integrity caused by the loss of lignin. The above image illustrates a bulge caused by reactive tree tissue, and then a cross section of the bulge shows the white discolouration caused be the fungus.
Brown rot can be more difficult to spot as the lignin remains in the tree, thus maintaining tree rigidity and preventing the tree from laying reactive tissue. However the lose of cellulose reduces the tree’s flexibility. In some ways this can make brown rot more dangerous as there may be fewer or no visible signs of the decay, or imminent failure.
