Competition for resources in a dead birch

More often that not, we’ll only see one fungal species overtly present within a tree (by the presence of sporophores). However, at times, we may see two (as is the case in this example). Of course, this doesn’t mean these are the only species present, as the mycelium of other fungi may be spreading within the wood substrate but simply not producing a sporophore, or spores may even be ‘latent’. But then, I suppose, it’s a case of how deep down the rabbit hole do you go?

Staying well-and-truly out of such a rabbit hole, I am sharing below a really nice example of how the stem of a dead Betula pendula (silver birch) is host to both Piptoporus betulinus (birch polypore) and Daedaleopsis confragosa (blushing bracket). They occupy different portions of the stem, with the former placing high up and the latter low down, though I very well imagine there is, or soon will be, marked competition between the two species’ mycelial networks for resources (the birch isn’t markedly decayed, so it may have only died recently). After all, fungi are very territorial, and certainly don’t like to share.

Who will win here (?), and I wonder whether the birch polypore has the advantage because it’s a specialised opportunist (it is present in the sapwood system of its host prior to stress / death), though also because it has gravity on its side. Will gravitational forces make it harder for the mycelium of the blushing bracket to grow upwards, when compared to the mycelium of the birch poypore growing downwards? Just a theory…

At the bottom of the stem we can see many fruiting bodies of the blushing bracket, and further up a few of the birch polypore. Somewhere in the middle there will be a competition for resources, either going on currently, or soon to be taking place.

A closer look at some of the blushing brackets. Note some white marks on the bark in places, suggesting perhaps old bracket locations.

Closer still, in this image.

Looking up, and taking care not to scorch my retinas, I snapped this shot of the underside of one of the birch polypore sporophores. This was the largest one – I could count three more, with one above and two on the other side of the stem just a little further down. This fungus’ spores would have latently present prior to the death of the birch, because the fungus is a specialised opportunist. Perhaps this will give it the advantage over the blushing bracket?