AHCARB408 — Perform a ground-based tree defect evaluation

Elements & performance criteria

Performance evidence

• 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.

Knowledge evidence

• 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.

Foundation skills

• 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

Unit content sourced from training.gov.au — © Commonwealth of Australia, licensed under CC BY 4.0. Auditori is not affiliated with the Department of Employment and Workplace Relations.

Questions about assessing AHCARB408