I was called in by a concerned tree owner because his mulberry tree had partially collapsed.
His main concern was obviously that the tree could no longer be retained.
As the tree was a major landscape feature in his garden he really needed to know whether tree retention was a possibility.
The tree divides into three main stems at about 1m. The point at which the stems divide was weak and had resulted in an entire stem collapsing to the ground.
The stem was not completely detached from the rest of the tree and therefore in my opinion it was feasible that the stem could be retained as long as the remainder of the tree was made safe.
I proposed removing the majority of the crown from that stem and winching the lighter stem back into place.
It could then be temporarily held in place using a ratchet strap and some wooden props.
At this stage the remainder of the crown could then be reduced to further lessen the loading at the structural weak point.
Three bespoke iron props were then built and installed by a skilled ironmonger. Great care was taken not to damage any of the roots.
With the props installed, the ratchet strap was removed allowing the stems to settle into their new support system.
With monitoring and careful future maintenance of the tree I hope it will now remain standing for many more years to come.
It is possible to identify potential structural weak points in trees through the understanding of certain visual indicators.
This Sycamore was next to a road and very close to some electricity lines. It was approximately 12 m tall.
The tree forked into two stems at about 1.5 metres in height. Included bark (line of tight inwardly folding bark) can be seen running from this point to the ground. The other side of the stem mirrored the included bark indicating a potential crack within the tree.
Included bark is a good indicator of a weak union in a tree.
This weak point of the tree could have split in high winds causing major damage to the electricity lines and could possibly have caused an accident on the road / pavement.
Due to the high risk target area the decision to remove the tree was made.
When the tree was dismantled it became evident how serious the crack was. At some points there was only a few inches of holding wood preventing the tree from failing.
If the tree had been in a low risk target area it could possibly have been retained by performing a crown reduction and with the installation of stem bracing equipment. This would have reduced the forces and loading at the point of the weak union, creating a safer structure.
In this instance, bracing would not have been appropriate and if the tree had failed, causing damage to people or property, then the tree owner could be found negligent in fulfilling their ‘duty of care’.
Unfortunately this tree was found to have several fungal fruiting bodies of Phaeolus scweinitzii, one on its root plate and two at the stem base.
This fungus causes a brown cubical decay, the rot usually starts in the roots and spreads into the stem causing butt-rot.
The rot can then cause the stem base to fail in high winds.
A specimen of the fungus was sent to a laboratory for testing to confirm it had been identified correctly.
Due to the high risk target area (busy main road) and potential danger caused by this fungus the tree could not be retained.