Can't see the wood for the trees
Armed with our trusty clipboards, binoculars, and rubber mallets, join the Ranger team as we venture through the trees to carry out our annual tree safety inspections.
If you go down to the woods today
Any visitor to Attingham knows we have a number and variety of trees on the estate; from the distinctive Lebanon cedars next to the Mansion, the 650 year old Repton oak in the Deer park, to the woodlands and old plantations across the wider parkland. All these trees are a wonder to walk through and experience but we have as much of a duty of care to what is around the trees as we have for the trees themselves.
This is where the Rangers come in; around this time each year we head out to perform visual inspections of trees around the estate, whether it’s a cottage, a footpath, or even the mansion itself. We assess the trees and make decisions as to any work that needs carrying out.
So what are we looking for?
There are a variety of signs and features that we use as indicators as to the health of trees. These can range from the more obvious such as damage to branches, and large open cavities in the trunk; to the more subtle like partial crown die back, hollowing of the base and buttresses, and weak branch unions. One of the main things we look out for though is whether any fungi are growing on the trees we’re inspecting.
If you’ve ever walked through the woods in autumn you’ll have noticed that fungi come in a variety of shapes, sizes, or colours, and with this variety also comes various feeding habits. Some fungi are quite extensive, being found on a variety of tree species whereas some are a bit more choosey. An example of each is honey fungus which can be found on various broadleaved and coniferous trees, while chicken of the woods prefers oak trees.
What rotten luck!
Some of you reading this may have heard of the phrases ‘white-rot’ or ‘brown-rot’. White-rot is when the fungus eats away at the browner lignin of tree cells, the structural support of the tree, leaving the softer, whiter cellulose. The result of this is a tree that gets more flexible, but trees are clever and they add additional growth at their bases to compensate, allowing them to stay standing for a while longer. Brown-rot is then the opposite, the cellulose gets eaten leaving the lignin and the tree gets more rigid and stiff and cannot put down additional growth. Trees with brown rot will eventually become brittle and snap.
Flight or failure
Fungi can live within trees for years with no obvious signs. The bit you see is what’s known as the fruiting body and are the part responsible for reproduction. When a fruiting body appears on a tree it is usually because the nutrients within the tree are running out, which can happen for one of two reasons. Firstly, the tree may have managed to create a barrier between fungus and the remaining healthy tree tissue, kind of like a scab, preventing the fungus from continuing. The other reason is that the fungus has managed to eat all of the wood inside the tree.
In either case, there is only a limited amount of nutrients left which causes the fungi to essentially panic and want to move out. As you can see below, the large amount of honey fungus on the tree stump is likely because it has used up the rest of the nutrients since the tree was cut down.
A discerning eye, and ear
So how do we know whether the tree has successfully fought off the fungi or if it has eaten everything? This is where our training and trusty rubber mallet comes into play. By tapping on the trees with the mallet and listening to the sound, we can start to work out whether the wood inside is still solid or if cavities are beginning to form because of decay. By identifying any fungi growing on the tree and assessing how much of it there is, we can make decisions as to what to do with the tree. For example, the beefsteak fungus is brown-rot causing, meaning the tree will grow brittle. But beefsteak is slow growing so if it isn’t big or extensive on the tree, then there won’t be much internal damage.
However, even though a tree may have extensive rot, a large open cavity, and a couple of splitting branches, we may decide not to do anything to it. If the tree isn’t a threat to person or property, we can leave it where it stands. The various features that may make the tree ‘unsafe’ are the same features that make it ideal for wildlife. Cavities and splits in the bark or branches can be perfect habitats for bats, while the decaying wood is just the right home for various bugs and beetles. So the next time you're out in the woods, take a closer look at the trees and see what you can spot.