My folks have/had a well established Liquid Amber tree which fell on their fence during a recent high wind event.

I understand that the local council has fairly recently been laying fiber cable and doing some other reticulation work in close vicinity to the tree.

How likely is it that this root damage would have caused by this work.

Also, looking at the pictures below, is anyone able to hazard a guess as to how long the tree may have been rotting for, and how apparent this would have been prior to the tree falling down, had there been periodic inspections of the tree.

Also, how common is this kind of problem with these types of trees ?

Rotten tree 1

Rotten tree 2

1 Answer 1


This type of occurrence is called a split due to a weak crotch and two competing leaders. The split has been inevitable for many years, and was just waiting for the weight of wood on one side or the other to pull the branch down. It is quite commonly seen. The activity in the root zone probably has no relevance; while this may have reduced the overall vigour of the tree the split was an event waiting to happen for many years.

Tree surgeons are often able to detect this kind of weak crotch and can either reduce the weight of wood on the weak side or brace or cable the two competing leaders together, each supporting the other. Ideally when a tree is young and it is clear that two competing leaders are developing we can remove one so that the weak crotch never develops and the tree can fill in the inevitable gap. However, interfering with the point of weakness to detect its state of rot itself would probably weaken it further so the operation would not be carried out.

Local authorities are usually very careful to lay cable only on land they own. If private tree roots expand onto their land then that is unfortunate but they can have no responsibility for damage caused to the roots.

Most trees, including Liquidambar, are subject to the competing leader problem. When inspecting trees, look for the angle between the competing stems; a wide angle is perhaps okay, but a sharp or acute angle is a sign that weakness may be present.

Edit: when you come to do the cleanup, examine carefully what remains of the tree once the fallen part has been removed. You may find that the remaining leader is badly unbalanced and might need to be reshaped to restore some stability. Assess where it might fall if it goes over and evaluate potential damage if and when it does.

  • Thank you for this. The tree is actually on council land and they are denying liability for the damage it caused!
    – davidgo
    Feb 12, 2017 at 18:19
  • 1
    I am not a lawyer, but I would think that the council is on shaky ground. Many Parks Departments keep an inventory of their trees and watch them carefully. If there is a lot of damage, call in an independent arborist and ask him for an assessment of what happened. Listen for the term "co-dominant leaders." Keep your local councillor informed. Feb 12, 2017 at 18:32

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