Decay Detection Testing

These methods use the latest technology to give you more information about your trees or those of your client.

Methods include:

  • Non-Invasive Decay Detection Testing
  • Sonic Tomography (Picus), in our case ArboTom
  • Invasive Decay Detection Testing
  • Resi 400 PD Micro Drill (also known as Resistograph)
  • Trunk Coring Sampling
  • Chlorophyll Fluorescence Testing

Decay detection testing equipment falls into 2 categories, non-invasive and invasive.  The non invasive uses sound waves travelling through the wood (similar to an ultrasound devicee), and invasive uses a 3mm diameter drill to measure resistance to drilling.  We at Arbor Cultural Ltd have both types of equipment, as well as tree corers and Arbor Check chlorophyll fluorescence testers to measure trees vitality and stress levels.

Using this technology can aid sound arboricultural knowledge and will enable:

  • Greater certainty about condition of the trees internal structure
  • Assist tree works applications, providing the analysis that Council’s require
  • Greater peace of mind over trees of concern, allowing you to sleep better at night
  • Retain trees longer with minor tree surgery, (creating long term clients for tree surgeons)
  • Monitoring the often relatively slow decay process

ArborTom Sonic Tomography

The ArboTom Tree Tomograph is an instrument for tree risk assessment and wood quality evaluation. It quickly provides an impression of the inner condition of a tree. If used in conjunction with ArboRadix it can even detect roots below pavements.

Sound waves travel through sound wood. Sensors around the tree measure the time it takes an impulse to travel through the wood and reach the other sensors. The collected data is simultaneously sent to a computer, which turns the data into a coloured image to visually represent the trees cross-section.

This is a fast and easy to set up test, that is non-invasive and non-destructive.

It is the only device on the market to measure at different heights of the tree simultaneously. The sensors are set at two or three separate horizontal levels and the acoustics across and between the levels is recorded. This allows it to produce a genuine three-dimensional interpretation of the internal condition of the tree.

Invasive Decay Detection RESI PD400

We at Arbor Cultural Ltd. have just invested in a new IML RESI-PD400, upgrading it from our previous IML RESI F300S. This new specialist instrument is designed not just for an accurate measurement of the resistance given by wood to drilling (torsional resistance), but also an accurate measurement of the pushing force required to penetrate the tree stem.

This can be used as a tool to determine the strength loss of a stem or branch, to help determine whether it can be retained, and whether any form of tree surgery is required.

Resistance to drilling by wood is not a complete measure of wood strength, but resistance is usually significantly reduced if wood is weakened by decay.

The additional measure of the pushing force, incorporated into this new device is important as it assists in the measurement of some structural loss due to certain types of decay, which were not so evident from just the rotational measurement.

Both of these readings are displayed on a digital readout on the top of the device, which can be exported as a graphical image into a report.

This device is used to excavate a narrow penetration track with a fine drill where decay is suspected. The IML RESI-PD400 has a drill diameter of approximately 3mm and a drill length of 400mm.

The RESI drill bit causes minimal damage as it is of very small diameter which leaves a narrow penetration track. It also does not remove the wood fragments when extracted.

Invasive Decay Detection Core Sampling

If the RESI PD400 has identified significant decay, this can be confirmed by extracting a core sample of the tree and then inspecting the sample to determine the extent of decay and strength loss.

A link below shows how a core sample is taken from a tree.

https://www.youtube.com/watch?v=jPJUewNcvao

Tree Vitality Testing

We at Arbor Cultural Ltd. have just invested in some new equipment to test how healthy trees are. We have purchased an Arborcheck system for measuring tree vitality.

The system consists of two items, a Chlorophyll meter and a Chlorophyll Fluorescence meter, which are used in conjunction with one another. Chlorophyll content values taken from leaves during tree health analysis with the Arborcheck Chlorophyll Fluorescence system may be entered into the Arborcheck App where it is analysed as a component part of the Benchmark Values Database.

Chlorophyll Fluorescence and Chlorophyll Content are both non-invasive, non-destructive field based techniques that are quick to complete, and it can be repeated regularly. In essence, they are superbly positioned to quickly and effectively screen for tree deterioration due to a stress-related reduction in photosynthetic capacity.

The potential applications are:

  • Monitoring trees on development sites
  • Monitoring trees suffering from disease
  • Monitoring trees undergoing some form of treatment
  • Checking trees prior to purchase from a nursery
  • Checking newly planted trees during post-planting maintenance

Leaves can essentially be likened to photovoltaic panels in that their main purpose is to take energy from the sun and convert it to a different form of energy; in this case, complex carbohydrates that the tree may use for nutritional value. This is the main principle of photosynthesis.

Any biotic or abiotic stress that a tree is suffering from will limit the amount of carbohydrate available for growth and therefore reduces nutrient uptake resulting in leaf chlorosis and necrosis. Exact knowledge of foliar chlorophyll concentrations, i.e. leaf greenness, consequently provides a robust and accurate estimation of tree vitality.

Any form of biotic or abiotic stress, which have an effect on the photosynthetic capacity of the tree will alter the intensity of the chlorophyll fluorescence emission. Consequently, we can use a Chlorophyll Fluorimeter to measure the changes in the extent of fluorescence emission to infer information about the efficiency of light use for photosynthesis.

Please contact Arbor Cultural Ltd for a free quotation.