Best Practice Regulation

Best practice guidance for the application of VOSL in government regulation of risk. Published by The Australian Government, Department of the Prime Minister and Cabinet, Office of Best Practice Regulation. This note provides guidance on how officers preparing the cost-benefit analysis in Regulation Impact Statements should treat the benefits of regulations designed to reduce the risk of physical harm.A number of regulatory proposals are aimed at reducing the risk of physical harm, for example, occupational health and safety laws, warning labels on tobacco products and transport safety measures such as seat belt laws. This raises the issue of how to measureand articulate this benefit in a Regulation Impact Statement. Different methods have beenproposed for valuing reductions in the risk of physical harm and this note sets out a methodmost appropriate for the best practice regulation process.

Management of the Risk of Falling Trees​

This guidance to UK Health and Safety Executive and local authority enforcing officers appears to be a change in direction for HSE. The theme of the guidance is that it is reasonable to assess the risks from trees without seeking to assess every tree in detail. This document was updated in March 2013, but is not available as a pdf document. You can view the revised document at

Quantified Tree Risk Assessment

This colour-coded framework is designed to assist tree risk management decisions using the output of a Quantified Tree Risk Assessment.

Report on fig trees at Laman Street, Newcastle, NSW. Commissioned by Save Our Figs Inc.

At Laman Street in New South Wales, an avenue of fourteen fig trees was removed by Newcastle City Council against considerable opposition from local people. Over 12,000 people signed a petition to save the trees; the second largest petition in the history of NSW. At the end of December 2011, Mike Ellison was commissioned to carry out a Quantified Tree Risk Assessment of the affected section of Laman Street. This is the report presented to the local residents group ‘Save Our Figs Inc.’.If you would like more information or wish to discuss the case, you can post on the Public Discussion Forum in the ‘Tree Manager’s Resources’ section, or if you are a QTRA user, you can post on the User’s Discussion List.

Review of QTRA and Risk-based Cost-benefit Assessment of Tree Management

Published in Arboriculture and Urban Forestry 2013. 39(4). The lead author of this paper is Mark G. Stewart, who is Professor of Civil Engineering and Director of the Centre for Infrastructure Performance and Reliability at The University of Newcastle in Australia. Professor Stewart’s biography cites authorship, with R.E. Melchers, of Probabilistic Risk Assessment of Engineering Systems (Chapman & Hall, 1997), as well as more than 300 technical papers and reports. He has more than 25 years of experience in probabilistic risk and vulnerability assessment of infrastructure and security systems that are subject to man-made and natural hazards. The Paper is supportive of the QTRA approach, but identifies some shortcomings. Some time prior to publication, Professor Stewart communicated by email his initial thoughts on some of these issues. The QTRA method was modified accordingly and we remain grateful for this contribution.

Additional downloads

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Resources for Registered Users

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QTRA Updates

Available only to Registered Users.

Registered User Projects

If you would like to share a case study with other QTRA users or have an interesting project that you would like to discuss why not have it uploaded here.  If you would like to upload a file to the Registered User Projects area, contact Mike Ellison by email at

Audio Files

Taking Rot Seminar 1993

In 1988 a seminal work ‘Fungal Decomposition of Wood – its Biology and Ecology‘ was published by John Wiley & Sons – ISBN 0 471 10310 1.  But it wasn’t until 28th April, 1993 that the UK arboricultural industry was introduced to its authors Dr Alan Rayner, Reader in Mycology, University of Bath and Dr Lynne Boddy, Senior Lecturer in Mycology & Microbial Ecology, University of Wales at the seminar ‘Talking Rot’ hosted by the Arboricultural Association at Berkshire College of Agriculture and Windsor Great Park.

This was the first and as  far as we are aware, the only seminar to be professionally recorded for the Association, with whose kind permission we have had the recordings digitised so that these important lectures can be made available to all.

Whilst Alan and Lynne were using slides in their lectures, these are only audio recordings, but  their first class delivery paints the pictures for the listener.


New Avenues for Understanding Tree Decay. Alan Rayner (part 1)


New Avenues for Understanding Tree Decay. Alan Rayner (part 2)


Did it Fall or Was it Pushed – Is Fungal Decay an Inside Job? Lynne Boddy (part 1)


Did it Fall or Was it Pushed – Is Fungal Decay an Inside Job? Lynne Boddy (part 2)


Register your interest in qtra

Register your interest in QTRA training and we will send you an Introductory Information Pack and keep you informed of developments and training events.  When you have registered interest, you can select an event from our Training Calendar and make an online booking.


Our extensive global training courses and workshops will help you become an expert in tree safety and management. Attend one of our training courses to become a registered user of the system.


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