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Advanced Tree Risk Assessment

September 19, 2019 @ 9:00 am - 4:00 pm
Instructor: Dr. Julian Dunster CEUs: 6.0 ALMTU, 6.0 B-M

Tree risk assessment is an area of urban forest management that has evolved rapidly in the past decade. We have moved from simple hazard tree assessment concepts into a more sophisticated understanding of risk in general. With the introduction of the ISA’s Best Management Practices document for Tree Risk Assessment, and the Tree Risk Assessment Qualification (TRAQ), several new approaches and guidelines have been introduced. Within the field of tree risk assessment there are many techniques and concepts to master; from basic principles through to sophisticated diagnostic techniques.

This course will focus on Level Three advanced tree risk assessment, but will also link this to Levels One and Two to show when Level Three may be required, and how to relate it to other work.

This course will be delivered by Dr. Julian Dunster, the designer of the original Certified Tree Risk Assessor credential (TRACE) and author of the new ISA Tree Risk Assessment manual for the TRAQ course. The course will be of interest to anyone practicing tree risk assessment, and especially arborists already holding the Tree Risk Assessment Qualification.


Levels of Assessment

Review how each level feeds into the next one to provide increasing levels of detail.

The Implications of Advanced Assessment: An Overview

  • why do you need it?
  • asking the right questions
  • knowing what to look for
  • knowing what you are looking at
  • professional and legal implications

Knowing What to Look For

  • baselines: the biological and mechanically ‘perfect’ tree
  • variations around ‘perfection’ and what they might mean
  • Knowing what you are looking at
  • Body Language: how to read and interpret it
  • Theorising ideas about what any one variation might mean
  • How to test your theory and see if you are right

Testing Techniques

  • Invasive versus non-invasive issues
  • discussion
  • core sampling
  • Micro resistance drilling
  • sonic tomography
  • Interpreting the results, and relating these back to the risk assessment

Documenting and Defending the Results

The importance of clearly documenting the thought processes that lead you to undertake a Level Three assessment. Showing where, why and how you tested, and what you concluded based on the results.

Class Session Discussion of Real World Examples

Participants are encouraged to submit beforehand a brief outline of a case study about investigations or anomalies they have encountered (details will be provided with the registration information). Up to six of these will be selected for presentation and discussion in class. We will examine the basic issues and then decide what we would have done, and how we might have interpreted the issues to arrive at a conclusion. Submission are to be made directly to Dr. Julian Dunster, with the following subject title 'Case Study Submission - Advanced Tree Risk Assessment - September 19', and to the following email address: jd@dunster.ca


Location: UW Center for Urban Horticulture, 3501 NE 41st Street, Seattle, WA

  • 9:00 to 10:00 Introduction
  • 10:00 to 10:15 Break
  • 10:15 to 11:15 Biomechanics Part 1
  • 11:15 to 12:15 Biomechanics Part 2
  • 12:15 to 12:45 Lunch
  • 12:45 to 1:45 Testing Protocols
  • 1:45 to 2:00 Break
  • 2:00 to 3:00 Typical Tests
  • 3:00 to 4:00 From Theory to Practice


Dr. Julian Dunster has unique academic and professional qualifications. He is a Registered Consulting Arborist, a Registered Professional Forester, and a Registered Professional Planner, and in addition to two degrees in forestry, he holds a Doctorate in Regional Planning and Resource Development. Julian has over thirty years of hands on experience from assignments all over the world, and his innovative work has been recognized with many awards. Julian uses these qualifications and expertise to provide you with practical, science based information, combined with a pragmatic understanding of what will or will not work well.

Refund Policy

  • Cancellations made at least 10 days prior to the event will be refunded at 100%.
  • Cancellations made within 5-9 days of the event will be refunded at 75%.
  • Cancellations made within 1-4 days of the event will be refunded at 50%.
  • Refunds will not be made available for no-shows.

Late Registration

  • Participants are expected to enroll prior to the registration deadline.
  • Participants can register at the door of the event only if space is available. Individuals will need to pack their own lunch.
  • Late registration is possible on a space available basis. You can contact our office at (800) 335-4391. There may, or may not be, room available for those who show up without registering ahead of time for the workshop. We encourage you to register for the workshop in advance.

Allied Professionals are members of allied organizations. See our list of qualifying organizations.


University of Washington – Center for Urban Horticulture
3501 NE 41st Street
Seattle, WA 98105 United States