DECAY MAPPING
 

Decay detection /mapping.

Most modern technologies allow non-invasive solutions to internal decay / fault finding procedures. Whilst VTA can provide extensive valuable information upon the internal condition of trees, it is open to subjectivity and can be easily misinterpreted.

Most of the following technologies provide a visual representation of the internal parts of trees whilst avoiding damage to the delicate tissues. Any injury to a tree remains for the life of the tree and can provide entry points for pest or disease. Similarly, trees that are already decaying internally normally develop natural barrier zones in an attempt to limit the spread of decay. Any invasive investigation can damage or break these natural barriers and allow decay to spread into formerly healthy parts.

Any invasive method must be approach with caution, experienced users only should carry out the procedures and when only necessary, often to establish the 'physical' size/ width of remaining supportive tissue to allow a calculable risk analysis of the trees' stability to be made.

At Barnes & Associates digital scanning in the form of a Picus tomography equipment can provide cost-effective and definitive answers , in a visual form for clients in most situations whilst protecting trees from unnecessary damage. The investment is paying off more and more trees are been 'saved' as we can now accurately map and analyse the trees structural integrity without invasive techniques.

We currently have two fully trained staff who have attended  Picus tomography 'Master training days' and Ian Barnes who as attended numerous seminars on tree stability and wind loading dynamics to enable a more quantifiable management approach rather than 'gut feeling' which is all too common within the industry.

Thermography - Currently Out sourced.

Infra red thermal imaging cameras can be used to detect internal faults within tree stems, branches and root collars without the need to injure the subject. The heat differences between hollow, sound or decayed wood is often great allowing Thermography to pinpoint potential zones of weakness.

Thermography surveys are rapid allowing a quick assessment of above ground tree parts that would normally prove difficult to assess with other equipment. In tree stems, Thermography can provide evidence of internal damage and ensure that other investigation procedures are accurately deployed.

Thermography is completely non-invasive therefore completely safe for use with trees. See also Infrared Photographic Analysis and Ground Penetrating Radar. We are awaiting more accurate results for stability assessments before investment is made.

Tomography - In house

 We currently have two fully trained operatives. Our equipment is used as a tool to further assess suspect trees, we would advise our client if we felt the tree required this further in depth assessment , we will not undertake a Picus assessment when it is not in our opinion necessary so avoiding misuse and misapplication of the tool to the benefit of our clients.

What is it?         Tree Body Scanner?

This technology provides a digital image of a tree cross section similar to a body scan in humans. This relies upon sound or stress waves being transmitted through the wood to various sensors and can provide either a two or three-dimensional image.

Tomography is virtually non-injurious unlike many other internal decay detectors though provides highly accurate images thus allowing more accurate assessment of tree integrity. See also Acoustics.

 Recent scans 2006:

Beech , decay within a co-dominant branch.

Scan carried out at 4 Meters of height.

Scan carried out close to suspect decay area.

 Stability Assessment (Static)

Digital sensors installed within trees to measure the displacement of the tree under wind load. Sensors can remain in place over a specified period or a simulated load can induce gale force conditions and allow an assessment of a trees ability to withstand such load.

This approach is virtually non-injurious to the trees system as it measures movement.

Vigour Assessment (Chlorophyll Fluorescence)

This technology allows the sampling of leaves, either still attached or recently removed from the tree, to determine the response of its Chlorophyll to light.

The reaction of Chlorophyll is indicative of tree vigour and can indicate the health and vitality of the subject tree. This simple test can therefore answer that all too familiar question “is my tree healthy”.

 Resistograph - In house

The Resistograph is highly sensitive tool that can be used to give an insight into the growth rate of a tree or used to confirm the location of decay within the tree, the remaining sound wood thickness thus identifying whether or not internal decay has advanced beyond safe limits. By drilling a small hole and recording the resistance that the wood offers to the probe, the equipment can determine the difference between sound or decayed wood.

This testing is invasive albeit a very small hole diameter, as such, this is generally carried out only when severe reservations are held as to the trees integrity and retained wall thicknesses are close to limits, normally  Picus Tomography to confirm earlier findings.

Copyright © 2006 Barnes & Associates