What is PiCUS Sonic Tomography for Trees?

In a nutshell: PiCUS offers Advanced Tree Decay Detection for Tree Risk Assessment

When internal tree decay is suspected, visual inspection alone often cannot reveal the full picture.

For tree safety, liability, and important tree retention or tree removal decisions, a more detailed investigation is essential.

This is where PiCUS Sonic Tomography provides clarity and is an invaluable part of the tree safety and risk assessment toolkit we offer our clients.

Typical scenarios when PiCUS Sonic Tomography is useful include:

• Situations where tree removal is costly, environmentally or reputationally sensitive
• Internal decay or cavities are suspected
• Fungal fruiting bodies are present but the extent of decay is not visible
• High-value, protected, or prominent trees
• Trees in high-use areas (public spaces, buildings, footpaths)

What are the Benefits of PiCUS Sonic Tomography?

Sonic Tomography is a Level 3 Tree Survey which gathers evidence to support proportionate and defensible tree management decisions. Many trees with defects can remain safe and viable where sufficient sound wood is present. PiCUS helps to determine this, and informs decisions on tree retention on removal.

We often carry out PiCUS investigations alongside a QTRA tree risk assessment, providing a robust risk rating for the tree and specific tree management recommendations in one single professional report.

Our clients appreciate that we can strengthen their evidence of duty of care to users of their sites, by including PiCUS in our tree safety and risk assessments. As well as supporting duty of care compliance Sonic Tomograph reports also strengthen planning submissions, estate management decisions and tree-related insurance claim scenarios.

What does a PiCUS Investigation Involve?

Picus is a non-invasive diagnostic system that assesses a tree’s internal structural condition. Small sensors are placed around the trunk, and a controlled sound impulse measures how quickly waves travel through the wood. Slower sound indicates decay or compromised areas, which are mapped into a colour-coded tomogram — revealing zones of sound wood, reduced density, cavities, and internal decay.

A tomogram does not automatically dictate “retain tree” or “remove tree”. This decision is made based on professional arboricultural interpretation of the findings within the context of tree species, stem diameter, structural loading, site usage, and overall tree vitality.

Sonic tomography findings strengthen professional judgement – it doesn’t replace it. So your choosing a qualified and experienced Arboricultural Consultant to advise you is essential.

How do I Choose an Aboriculturist to carry out my Picus investigation?

It is essential to work with an Arboricultural Consultant who not ownly owns their own PiCUS Sonic Tomography kit but who is also highly qualified and experienced in Arboriculture and interpreting and advising correctly on PiCUS Sonic Tomography investigation findings.

Enviroscope have been providing trusted PiCUS investigations using our own kit since 2018, and have extensive training and experience in interpreting precise and specialist tomograph field measurements.

We also have the professional and Chartered accreditations to reflect the arboricultural expertise needed to make safe, proportionate tree management recommendations to our clients. Find out more about our Principal Arboriculturalist Guy Morrison and his tree expertise.

Our clients include managers of parks and gardens, school and university grounds, hospitality venues, visitor attractions, housing associations, local authorities and homeowners. To read about one of our projects head to one of our PiCUS sonic tomography investigation case studies.

Looking for a Tree Expert to Help You Manage Your Trees Better?

If any trees on your site raise concerns, our tree safety and risk assessment services – including Picus Sonic Tomography service – will provide invaluable insight. We can help you make safe, informed, and defensible tree management decisions, anywhere in the UK.

Reach us via our contact form or call us direct!