Application
This unit of competency describes the skills and knowledge required to examine trees from the ground, assess and test them for defects, evaluate the potential risk of failure, secure the site and report the condition to specialist arborist for a tree risk assessment.
The unit applies to individuals who work in arboriculture and apply specialist skills to provide solutions to technical and unpredictable problems. They work autonomously, instruct and monitor the work of others within a team. They use discretion and judgment in the selection, allocation and use of available resources.
Legislation, regulations and by-laws relating to the treatment and removal of trees apply in some states and territories.
Elements and Performance Criteria
Elements | Performance Criteria |
1. Determine evaluation requirements | 1.1 Confirm trees to be evaluated according to client brief 1.2 Undertake a site-specific job safety analysis (JSA) and record and implement control measures 1.3 Determine tree health and hazard benchmarks for project according to industry standards |
2. Examine tree visually for indicators of potential failure | 2.1 Examine tree for indicators of general poor health 2.2 Examine tree for visual defects 2.3 Examine tree for indication of damage from organisms 2.4 Assess examination outcomes to determine potential for structural failure of tree components according to industry benchmarks |
3. Undertake basic testing of tree for indicators of potential failure | 3.1 Conduct tests for cavities according to visual indicators 3.2 Expose root crown and examine for concealed root defects according to visual examination outcomes 3.3 Remove loose bark and examine stems for concealed defects according to visual examination outcomes 3.4 Assess test outcomes for potential impact on tree health and structural integrity according to industry benchmarks |
4. Record tree attributes and indicators | 4.1 Capture images and record botanical name, dimensions and location of tree under evaluation 4.2 Document the results of examinations and tests conducted for tree under evaluation 4.3 Capture images, location and visual indicators of defects in tree for inclusion in documentation 4.4 Estimate and record dimensions of defect and affected tree component |
5. Assess and mitigate potential risk, and document actions | 5.1 Identify possible targets affected by tree under evaluation from client brief 5.2 Assess identified defective tree components for structural integrity and potential risk on possible targets 5.3 Validate assessment of severe defects on structural integrity of tree with consulting arborist 5.4 Advise client of outcomes of tree defect evaluation where a heightened potential risk to targets is identified 5.5 Take action to mitigate potential risk according to client advice and workplace policies and procedures 5.6 Document action taken to mitigate potential risk on target |
6. Document and report hazards and recommendations | 6.1 Review and assess tree defect evaluation results, and consider options for resolving any unmitigated risk 6.2 Identify and document recommended options for client approval 6.3 Compile records, results and recommendations, and document tree defect evaluation report according to workplace procedures and industry standards 6.4 Submit tree defect evaluation report to client according to workplace procedures |
Evidence of Performance
An individual demonstrating competency must satisfy all of the elements and performance criteria in this unit.
There must be evidence that the individual has conducted a whole-of-tree defect evaluation from the ground for at least 20 individual trees with defects, from at least 10 different species.
There must also be evidence that the individual has:
performed a site-specific job safety analysis (JSA) and recorded and implemented control measures
determined tree hazard benchmarks for the project
considered relationship between tree species, defects and potential risk
examined trees for indicators of the following defects:
tree health
visible physical defects
damage from organisms
assessed examination results to determine potential structural failure
conducted tests to determine visual and concealed defects, including:
sounding accessible visual and concealed defects
probing accessible cavities
exposing and examining root crown
removing loose bark and examining for defects
assessed test results for structural integrity against tree hazard benchmarks
recorded details of tree under defect evaluation, including:
captured images of tree
identified tree to genus, species and common name
estimated approximate dimensions of tree
identified geographical location of tree
recorded the following attributes of the defects:
image of the defect
location within the tree canopy
visual indicators of the defect
estimated the dimensions of defect and affected tree component
identified potential target from client brief and assessed consequences of tree defects on structural integrity and risk to target
advised client on outcomes of tree defect evaluation
implemented action to mitigate tree hazard according to client and workplace procedures
documented actions taken to mitigate risk
reviewed tree defect evaluation results and assessed possible options for controlling hazard
identified and recommended action for client approval
compiled all results, records and recommendations, and documented in tree defect evaluation report according to workplace procedures
submitted tree defect evaluation report to client according to workplace procedures.
Evidence of Knowledge
An individual must be able to demonstrate the knowledge required to perform the tasks outlined in the elements and performance criteria of this unit. This includes knowledge of:
work health, safety and environmental hazards, assessing risk and the role of a JSA
preferred industry practices (as outlined in the Companion Volume) relating to tree defects and effect on structural integrity
structure and function of client briefs and their interpretation, including:
targets and the role of targets in tree risk assessment
industry and client tree hazard benchmarks
work health, safety and environmental hazards, assessing risk and the role of a JSA
noting and specifying tree under evaluation, including recording:
plant naming conventions
estimating tree dimensions from the ground
specifying geographic location on maps, pictures and global positioning systems (GPS)
tree examination procedures and methods from the ground, including:
signs and symptoms of health of trees
methods for determining tree health
tree anatomy and morphology relating to structural failures
tools and equipment required to assist in tree examinations, including:
cameras and digital imaging
sounding mallet and probing tools
materials
recognising visual indicators of tree defects, their causes and effect on structural failure, including:
visible and concealed defects, including cavities, cracks and included bark
common symptoms of diseases (e.g. rot, fungal growth, loose bark)
common signs of organisms (e.g. holes, frass, live organisms, loose bark)
testing procedures for confirming visual indicators of tree health and structural defects, including:
sounding and probing techniques for defects
loose bark removal and signs of defects
exposure of root crown to identify root and crown defects
health and approximate dimensions of the tree and affected tree part and defect
documentation of the tree defect evaluation, including:
digital imaging and photographs
reports and reporting styles and industry best practice
assessing tree hazards and likelihood of failure, including:
potential consequences
measures to rectify
types of potential target
urgency for notifications and gauging imminent threat
isolation of hazardous trees
moving potential target
size of tree and its defects
considerations for remedial action arising from defect evaluation, including:
aerial inspection
load testing
role of a consulting arborist, and seeking further advice from consulting arborist
laboratory testing
documenting and presenting reports to clients.
Assessment Conditions
Assessment of the skills in this unit of competency must take place under the following conditions:
physical conditions:
20 trees from 10 different species as stipulated in the performance evidence
resources, equipment and materials:
cross-sectioned tree components representing visual indicators of tree defects
computer and computer software
digital image capture device
specifications:
workplace procedures, instructions and client brief for trees requiring evaluation
preferred industry practices (as outlined in the Companion Volume) relating to tree defects and effect on structural integrity
relationships:
client and consulting arborist.
Assessors of this unit must satisfy the requirements for assessors in applicable vocational education and training legislation, frameworks and/or standards. In particular, assessors must have:
arboriculture vocational competencies at least to the level being assessed
current arboriculture industry skills directly relevant to the unit of competency being assessed.
Foundation Skills
Skill | Description |
Writing | Create, edit and proofread tree defect evaluation report and recommendations to ensure clarity of meaning, and accuracy and consistency of information |
Oral communication | Present complex information about tree defects to client using clear and convincing language, tone and pace appropriate to the client's understanding |
Sectors
Arboriculture (ARB)