Tree Risk News

  • 2022-08-13 8:56 AM | Admin (Administrator)

    Whilst rummaging through some of the UK's dusty Risk & Regulation Advisory Council archives, we strayed across 'A Worrier's Guide to Risk'. David Spiegelhalter (Chair of the Winton Centre for Risk and Evidence Communication at the University of Cambridge) put it together for them in the noughties.

    It's a great guide to thinking about risk, some of which applies to trees, on one side of paper - our favourite length for a subject.

    A Worrier's Guide to Risk | David Spiegelhalter

  • 2022-06-09 10:39 AM | Admin (Administrator)

    This is the one-side-of-paper Summary of our Tree Risk-Benefit Management Strategies.

    The history
    We were first asked to put this together by the Department of State Growth, Tasmanian Government, when they were adopting VALID. It's role was to explain what the Strategy is all about to the departments strategic decision makers. The Summary proved such a useful communication tool, it found its way into the Government Agency template, and we've released it for general use.

    How to use the Strategy Summary
    It works at two levels. If you're a Duty Holder, you can grasp the complete Strategy within the time it takes to take a few sips of tea or coffee. Similarly, if you're an Arborist you can quickly catch the eye of a busy potential client and add value to your service.

    Active Assessment - Every 5 years?
    We think a 5 yearly Active Assessment frequency in Zones of High Confluence is reasonable, proportionate, and reasonably practicable. It's what many Duty Holders are adopting. Here, there's strength in numbers singing from the same hymn sheet if a risk is realised and a claim or enforcement action is being threatened. However, this is a Duty Holders decision. If they have a lower 'risk appetite' and are prepared to spend more money, we don't have a problem with a shorter frequency of Active Assessment.  Just edit the PDF or Word Template.

    Tree Risk Management Strategy | Policy & Plan

    PDF
    Strategy Summary v9.0.pdf

  • 2022-06-08 9:49 AM | Admin (Administrator)

    We have several free Tree Risk-Benefit Management Strategy templates that we've released under a creative commons licence.

    You can read all about them on our Risk Management page, and download them as pdf files.

    We're happy to share them with you as Word Template .dotx files as well, which makes it easier to customise the few sections that you need to. We've included the fonts that you might not have.

    The is the version for a Homeowner.  It's the simplest with a Policy and management by Passive Assessment; which is keeping an eye out for Obvious Tree Risk Features you can't help but notice.

    Tree Risk Management | Policy & Plan - Homeowner

    PDF
    Homeowner TRBM Strategy v9.0.pdf

    WORD TEMPLATE
    Homeowner TRBM Strategy v9.0.dotx

    Here are the main fonts used in the Tree Risk-Benefit Management Strategies.

    Museo 700
    Source Sans Pro

    Georgia is the body text and that should already be on your computer.

  • 2022-06-08 9:38 AM | Admin (Administrator)

    We have several free Tree Risk-Benefit Management Strategy templates that we've released under a creative commons licence.

    You can read all about them on our Risk Management page, and download them as pdf files.

    We're happy to share them with you as Word Template .dotx files as well, which makes it easier to customise the few sections that you need to. We've included the fonts that you might not have.

    The is the version for a School, College, or University.  It's similar to the Landowner one, where the Duty Holder has no trained Arborists as staff.

    Tree Risk Management | Policy & Plan - School, College, or University

    PDF
    School TRBM Strategy v9.0.pdf

    WORD TEMPLATE
    School TRBM Strategy v9.0.dotx

    Here are the main fonts used in the Tree Risk-Benefit Management Strategies.

    Museo 700
    Source Sans Pro

    Georgia is the body text and that should already be on your computer.

  • 2022-06-08 8:50 AM | Admin (Administrator)

    We have several free Tree Risk-Benefit Management Strategy templates that we've released under a creative commons licence.

    You can read all about them on our Risk Management page, and download them as pdf files.

    We're happy to share them with you as Word Template .dotx files as well, which makes it easier to customise the few sections that you need to.  We've included the fonts that you might not have.

    The is the Landowner version.  The main differences between this and the Government Agency one is there aren't voting stakeholders that you're looking to help understand.  So there's no Introduction.  There's also no trained Arborist on staff, but this can easily be changed in the Plan.

    Tree Risk Management | Policy & Plan - Landowner

    PDF
    Landowner TRBM Strategy v9.0.pdf

    WORD TEMPLATE
    Landowner TRBM Strategy v9.0.dotx

    Here are the fonts used in the Tree Risk-Benefit Management Strategies that you might not have installed.

    Museo 700
    Source Sans Pro

    Georgia is the body text and that should already be on your computer.

  • 2022-06-08 8:32 AM | Admin (Administrator)

    We have several free Tree Risk-Benefit Management Strategy templates that we've released under a creative commons licence.

    You can read all about them on our Risk Management page, and download them as pdf files.

    We're happy to share them with you as Word Template .dotx files as well, which makes it easier to customise the few sections that you need to.  We've included the fonts that you might not have.

    The is the Government Agency version, which is the most comprehensive.  It's written with Introduction section to explain what the document is about to 'stakeholders'.  Also, Arborists are part of the staff, which isn't the case with the other Strategies.

    Of course, if the Duty Holder doesn't have Arborists, then it's to edit the document to explain that they'll be hired when necessary.  The Landowner Strategy covers this.

    Tree Risk Management Strategy | Policy & Plan - Government Agency

    PDF
    Government TRBM Strategy v9.0.pdf

    WORD TEMPLATE
    Government TRBM Strategy v9.0.dotx

    Here are the fonts used in the Tree Risk-Benefit Management Strategies that you might not have installed.

    Museo 700
    Source Sans Pro

    Georgia is the body text and that should already be on your computer.

  • 2022-06-06 11:34 AM | Admin (Administrator)

    We've updated the Obvious Tree Risk Features Guide to include a new panel for Construction Damage; which will also be in the Tree Alert App.

    The idea of including Construction Damage is for two reasons.

    1) It's an extension of encouraging high volume, low effort, citizen science tree risk assessment (Passive Assessment) to include substantial damage to the stem or roots of a tree.

    2) We thought it might also be useful to take advantage of having this many eyes on the ground, day in day out, who can report where a development is going horribly wrong.

    An additional panel, and smaller images, means we've been able to increase the number photos in the guide.

    The formatting of the Guide has been updated to include heading, subheading, and paragraph numbers, so it flows with our free Tree Risk-Benefit Management Strategies.

    Obvious Tree Risk Features Guide

    Tree Risk Management & Assessment | Obvious Tree Risk Features

  • 2022-05-22 8:18 AM | Admin (Administrator)

    Here's the new VALID Likelihood of Failure voting card for v2 of the Tree Risk App, which is in development.

    Tree Risk Assessment | Likelihood of Failure

    If it's new to you, VALID (from where we get our name) gives you 5 chapter headings and 15 subheadings, that can affect a tree's Likelihood of Failure.

    When you're carrying out a tree risk assessment, and have got to the tough Likelihood of Failure decision, VALID gives you a structure that guides through the factors you should consider.

    At its simplest level, VALID is a checklist of things to think about and you're welcome to this voting card we use in training.

    The most important change is:

    DEFECT to DECAY
    We'll finally be rid of any mention of the red DEFECT word in VALID's publications. Those of you who have been there from the beginning will know this has been a quest for some time.

    The first subheading under DEFECT is section modulus. That's because if you don't have a grasp of section modulus, and are relying on t/R ratios, you can't make a reasonable decision about the significance of strength loss from decay.

    If you're not a Validator, who's been trained to use the Tree Risk App, here's their guide on how they go about using the current version to get to a base rate colour. You should get a sense about how this elegant and sophisticated approach helps you with your likelihood of failure decision making from this.

    Likelihood of Failure | Decision Making

    Tree Risk Assessment | Likelihood of Failure

    Day 2 of Validator tree risk training is all about making robust Likelihood of Failure decisions. If you follow this guide, it's really difficult to get it wrong. If anyone tries to game the risk to get it where they want it to be, it's really obvious where they've got it wrong, and that's what they've done.

  • 2022-05-19 11:39 AM | Admin (Administrator)

    In this famous scene from 'Marathon Man', Laurence Olivier finds himself in the uncommon position of playing a retired Nazi Holocaust Dentist. 'The White Angel' escaped Germany with a cluster of stolen diamonds. He's not happy though, because he thinks his retirement stash is threatened. To find out whether it is, he's about to torture a tethered Dustin Hoffman by inflicting pain with a dental scaler, and giving relief with oil of cloves (ISO 31000?). The torment begins with him repeatedly asking, in an increasingly menacing tone

    Tree Safety Management

    "Is it safe?"

    "Is It Safe?"

    "IS. IT. SAFE?"

    Arborists and Urban Foresters are similarly tortured when they're asked about trees.

    "Is it safe?"

    They'll be asked.

    Well, is it or isn't it?

    Safe, to just about anyone, means a complete absence of risk.

    "Is it safe?", is a binary trap. If you answer, "Yes", and the tree then falls and kills, injures, or damages property, no matter how low the risk, clearly the tree wasn't safe.

    Tree Safety Management - A Binary Trap

    Safe enough?
    Even if you reframe the question by answering, "It's safe enough". Or, "It's as safe as necessary". What they'll hear and remember is the word 'safe', and safe to just about everyone means a complete absence of risk. What they won't hear, or will instantly forget is the all-important qualifying 'enough' or 'necessary'.

    Better safe than sorry
    Safe and safety are words that are all too vulnerable to being weaponised with hindsight or outcome bias as failures in the duty of care if a risk is realised. More than that, they can hamstring critical thinking. 'Better safe than sorry,' easily trips off the tongue without a second thought about what it really means. Or the unintended consequences of trying to achieve it. "Could we make it safer?" sounds like a reasonable request.

    Mind your language
    The language you use when talking about tree risk is really important. You can't make a tree safe. You can't remove all of the risk. But you can always make a tree safer by cutting some of it off. If we stick with risk words, we can diffuse lazy phrases like, 'Better safe than sorry' or 'If in doubt, take it out', because it translates to 'Better no trees, or less tree, than any risk.'

    If the risk from a tree is Acceptable or Tolerable, there's no reason to make it safer by cutting bits of it off. It's why you won't find the 'S' word in any of VALID's Tree Risk-Benefit Assessment and Management publications.

  • 2022-05-13 4:22 PM | Admin (Administrator)

    This is quite a long explanatory post, so here's the take home message:

    VALID represents a responsible body of competent professional Duty Holders, Validators, and Basic Validators who would agree there were no Obvious Tree Risk Features on the Cherry Tree in Hoyle v Hampshire County Council.  This tree did not have any obvious defects.  All the so called defects were natural features.

    Here's how we get there
    The Bolitho Test is a new one for us, which we think is profoundly important. From the recent Hoyle v Hampshire County Council Judgment in the UK:

    "Principal issues for determination
    Para 32

    (iii) was Mr. Soffe's/Mr. Power's VTA of tree 572 such that no competent Tree Inspector would have completed it in this way.

    Para 114

    …the Claimant must show that no responsible body of competent professional tree inspectors would have come to the conclusions and made the recommendations…

    (Bolitho v City & Hackney Health Authority)"

    What's a responsible body of competent professional tree inspectors?
    This is saying for the claim of negligence to stick, for an edge tree, with a natural lean and asymmetric crown, without noteworthy buttressing on the sheltered side, next to a ditch, to be considered anything other than normal features, NO competent Arborist would agree with this.

    Or to put it another way. EVERY other competent Arborist would need to agree that an edge tree, with a lean and asymmetric crown, without noteworthy buttressing on the sheltered side, next to a ditch, are not normal features. That they're a catalogue of 'obvious defects' that means you need to explore for roots on the sheltered side.

    Strategy - your first line of defence
    In VALID's Tree Risk-Benefit Management Strategies, we define what obvious risk features we're looking for in a tree (the word defect does not appear in any of the Strategies because it's a begging the question fallacy). The Obvious Tree Risk Features Guide is a free resource that's released under a creative commons license. Anyone is welcome to use it.

    Nothing to see here
    An edge tree, with a lean, asymmetric crown, lack of noteworthy buttressing on the sheltered side, next to a ditch has NO Obvious Tree Risk Features.

    How many competent professionals?
    Now, we're tree risk experts, not lawyers. But, reading about The Bolitho Test, it looks like the weight of a 'responsible body of competent professionals' needs to be more than AN Other. Which is fine, because if we took a random sample of 100 Validators, (responsible body of competent professionals) we'd be surprised if any of them would've taken a closer look at the tree in question.

    The Cherry tree was an Acceptable risk at a Passive level of assessment, and at a Basic level of Active Assessment.

    What lies beneath
    We know Ivy (and other vegetation that obscures the stem) can cause concern amongst some Arborists who assess tree risk. They feel they have to remove this vegetation because of what risk feature it might hide. We disagree, unless there's an Obvious Tree Risk Feature to trigger it's removal. This example from the Government Agency Strategy describes how a Validator deals with this kind of vegetation when carrying out an Active Assessment at a Basic level.

    "We won't remove climbing plants, undergrowth, basal epicormic growth, or cut hedgerows to get a closer look unless there's an Obvious Tree Risk Feature. It's only if we find these features the costs of removing vegetation, and loss of habitat benefits, are justified."

    A responsible body of competent professionals
    We've got a large and growing international group of Duty Holders, Validators, and Basic Validators (responsible body of competent professionals) who manage and assess tree risk without removing vegetation, unless there's a trigger to justify it.

    No matter how many natural features are being labelled as obvious defects because they appeared in a recent Judgment, Inquest, or Enforcement, and added to tree inspection training programs and publications, VALID is happy to share a responsible body of competent professionals that would take a very different view when it comes to managing and assessing tree risk.

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Contact: admin@validtreerisk.com

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