Some people may wonder why I bother writing a fungus of the week spot, when I work with trees and not mushrooms.
As well as fungi being a bit of a passion of mine, the truth is that, simply, the lives of trees, tree surgeons and fungi are very tightly intertwined. As I have posted previously, fungi interact in many ways with trees. They can act positively in helping to seek out nutrients and having a close association with the roots, or they can have negative effects being parasites of living trees, and making them grow less well, making them become unstable, or killing them. Walking in the woods at the moment you can see all of this happening a little more clearly, partly because we see the fruiting bodies of fungi more often at this time of year, so they become more obvious.
This fungus grows within the wood, and causes it to break down, removing an important component of wood, lignin, which makes the tree weak. About a meter above this bracket- there was no tree- it had sheared off in the wind and fallen, harmlessly into the woodland. On the edge of a road, a railway, or over a house, however, the outcome may be more serious, so as a professional tree surgeon, it is important that we know what we are looking at, and the implications of the presence of this fungus for tree and human health and safety.
It is also important that we know what it is, from the point of view of tree surgeon’s health and safety, especially if we are going to try to climb a tree that is likely to fall apart when we are in it!!
People who own trees quite often ask what a mushroom is near or on a tree and whether it is harmful. It is a good idea to not only learn the different fungi that are associated with trees, but to also carry a good identification book with you for back up. There is no shame in using an ident book, I have been doing this job over 30 years and I still take them around with me. There are several good guides, but a good basic, and really useful one is the Arboricultural Association Arborist’s Field Guide to Fungi on Trees by Guy Watson and Ted Green.
Decay does not necessarily mean death, and in some cases can be considered very useful, releasing nutrients back to older trees from wood that has been locked up for centuries. It can also help increase stability in some trees by changing their strength to weight ratio.
It is also quite nice to be able to tell the difference between fungi that are growing on the ground around the base of trees. They may give clues as to what is going on with a particular tree, and some species have benefits to humans as well as trees!
These are a couple of species I found, when I was out for a stroll with the dog this morning.
Both of these fungi grow in the same place, look similar, and are associated with the same trees.
Both form mycorrhizal associations with these trees, and although both may have a positive effect on tree health, they certainly won’t have on mine!
The one on the left is a fantastic edible mushroom which is now drying in my kitchen ready to cook with, and the one on the right can cause an upset stomach and so was left in the woods!
‘The Wood- Wide Web’
If you just gently scoop back the leaves on a woodland floor you will see this:
The white ‘roots’ are actually the mycelium of various fungi. This is the main part of the fungus, and makes up the vast majority of its ‘body’. The fruiting bodies, the brackets and mushrooms are what we are more likely to see, and they are produced from this mycelium.
If you look at the picture, you can see that the mycelium is growing through fallen leaves and is growing into, and breaking down, fallen wood. If you follow this back, you will eventually find that it links up with a tree root.
This has been dubbed the ‘Wood Wide Web’, it is a way for trees to tap into the nutrients from the woodland floor that would normally be out of their reach. Experiments have shown that nutrients are moved to different parts of woodland through this web, and that, particularly, young trees are plugged into it, allowing them to get a good start in life.
It has also been shown that trees communicate via this web, sending various signals via their roots, and their fungal attachments to other trees. This allows them, for instance to warn other trees of pests attacking them, and to prepare their chemical defences.
If you want to see a video on this, and other fascinating stuff about fungi, then watch the inimitable Paul Stamets on the subject by following this link: