Tree Stem

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Tree Stem & Main Branches to Assess Cavities, Holes or Decay

Trees are supported by wood and changes in the quality and /or its location can have significant implications for the tree’s safety. By understanding the wood produced by the tree we can provide an insight into the tree’s strength,  safety and identify areas of weakness to enable intervention management.

To directly assess the quality of wood we have several methods which broadly break down between those that injure the tree and those which allow the tree to continue to grow with limited harm.

Injurious methods
This can include Increment Bores, Resistograph or Wood Sampling, this can provide good information but leave a hole that can breach a trees internal defence mechanism, we typically only use this where there is a significant safety concerns or as a last resort.


Non-Injurious methods
Thermal Imaging

These produce images based upon the surface temperature of the tree and show subtle temperature changes across a section of the trunk or main branches. This method is good to rapidly identify areas altered by decay or with restricted or elevated vascular activity.

Microsecond Timer

This method records the time taken for a sound wave to travel between two sensors across a branch or stem. It provides an rapid insight into the condition of the internal wood condition or identifies the need or location of further assessment. The Microsecond Timer is very portable and so is good for rapid assessment during normal surveying or climbing Inspection.

 Sonic Tomography        

Sonic tomograms are produced by recording and comparing the time taken for sound waves sent from points around a tree. We use a system that uses up to 32 points providing a brilliant level of detail in comparison to other systems that can be limited to only 12 sensors or less. At its most simple the faster the sound wave the better the quality of the wood.

The information can be used to create 2D and 3D images a little like a body scan to provide a better understanding of the internal condition of the stem and understand the implications of the defect, the tree response and better understand its stability.

Electrical Impedance Tomography (EIT) 

This method measures subtle changes to the pattern of electrical current travelling through the stem or trunk of a tree and provides information on both chemical and physical properties. It can even identify areas currently affected by fungal colonisation but not yet decaying to enable us to understand where decay will be, not just where it is today. These results can be combined with other scans to provide a better understanding of the internal condition of the stem and the tree’s response to change.

RADAR Decay Mapping         

This method uses Radar (RAdio Detection And Ranging) measure the depth at which significant changed / margins in the wood occur to produce detailed information on shell thickness of a tree and can be combined with other scans to help understand tree safety. Reflections from air-filled hollow, or partially air-filled incipient decay can be detected by the systems, and provide a high level of detail on outer shell thickness and strength.

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