The internal, structural condition of the Beech tree was tested using a Picus machine.The Picus machine is a specialised electronic instrument which measures the speed that sound travels through the wood in a number of different positions and directions using a series of sensors.Sound travels fastest through solid wood and is slowed down when travelling through decayed wood. By measuring the speed that sound takes to pass through a tree, an idea of its internal condition can be obtained.The sounds are generated manually by tapping on a number of metal nails with an electronic hammer. Special sensors fixed around the stem read the interval the sound takes to travel through the wood.Once all nails have been tapped and the recordings taken, the computer software creates a visual, digital image.

The results indicate that the central area of the trunk is decayed/becoming decayed. Meripilus giganteus is a root rot fungus that severely decays the deep roots of trees, leading to them becoming unstable and prone to blowing over. In an urban environment, the results of this could be catastrophic.

When the fruiting bodies appear (in late summer or autumn) it is a sign that the fungus is already well established and that the tree is likely to become unstable (if it is not so already). Often with Beech trees, they will appear to be in good health. This is due to the fungus destroying the deeper-going roots first and leaving the shallower roots healthy and intact until last.

As the Picus test was carried out above ground level at a height of approximately 0.7 metres, and the results showed decayed wood at this height, it was concluded that the root system of the tree must also be decayed.

Based on the evidence provided by the Picus results, the presence of Meripilus giganteus and due to the location and size of the tree, the only safe option available was to remove the tree.