On Friday I made a post on Piptoporus betulinus and talked briefly about its colonisation strategy. You may recall that one of the images, which showed the underside of the bracket, had quite an interesting texture. As luck would have it, I think that I have just learned the reason (or one of the reasons) for this.
In his book Mycelium Running, Paul Stamets states that the ‘scent’ of the birch polypore attracts beetles that will, upon arrival, burrow into the spore-rich underside of the bracket and feast upon the inner flesh. As the beetles burrow in and feast, they are covered in spores. Upon leaving the birch polypore, the spore-laden insects will travel to another birch where they will bore into the wood and lay their eggs – all whilst depositing birch polypore spores.
The spores will then germinate and begin to form a mycelial web, which acts as a food source for the growing larvae. Because the mycelium induces a brown rot, the wood properties also change. In fact, as the wood properties change, woodpeckers are drawn to the tree in the search of grub to feed on. As the woodpekcers search for the beetle larvae, all whilst ‘damaging’ the wood during such a pursuit, they too act as a vector for spores – as does the woodpecker create conditions for other insects and birds to begin using this birch tree as a food source. Amongst all of the comings and goings of insects and birds, fungal spores hitch a ride, and the birch becomes a “launching platform” from which the birch polypore can continue its existence.