AHCARB513 — Examine and assess trees

Elements & performance criteria

Performance evidence

• identified scope and purpose of assessment from client brief
• selected, checked and used personal protective equipment
• located tree and documented position
• identified and recorded tree species and determined implication on brief
• assessed and considered tree health and impact on brief
• estimated age of tree, tree parts and defects
• determined and recorded tree dimensions, which must include: tree height, tree spread, diameter-at-breast-height (DBH), trunk circumference, diameter at base
• investigated, assessed and recorded the following indicators of value: habitat and ecological significance, historical and cultural significance, statutory controls
• selected and compared amenity tree for at least 2 different valuation methods
• collected unit values and data required by the valuation method selected
• calculated and recorded amenity value of at least 2 different trees
• compared results of different valuation methods and accounted for differences
• considered and communicated value of trees captured for valuation
• inspected tree for visual indicators of likely failure of tree or tree parts
• assessed relationship of tree to potential targets
• assessed likely impact of wind loading on potential for failure
• used basic diagnostic tools to confirm presence and extent of hazards
• assessed hazards and determined likelihood of failure
• selected tree risk assessment methods and determined their limitations
• determined target of concern and occupation rate
• determined tree components of concern and their likelihood of failure
• determined likelihood of impact and consequence of tree failure on target
• calculated and documented determinations and level of risk
• provided client with benchmarks and context for risk assessment
• determined and documented potential risk mitigation controls and estimated residual risk
• recommended timeframes for implementation of risk mitigation controls and follow-up inspections
• considered risk against value of tree
• produced a tree risk assessment report

Knowledge evidence

• areas to address in a client brief and developing the scope of assessment, including: purpose of assessment, owner/client and address, who requested the assessment, reasons for assessments to be requested, client risk thresholds, data capture procedures, requirements for assessment
• tree assessment and measuring equipment
• trees and surveying their location on a site, including: methods for locating trees on devices, drawings, plans or aerial images, techniques to position tree on site from boundaries and structures
• tree identification, biology and physiology
• assessing tree health, including: signs and symptoms of disease, methods of detecting decay and structural defects in trees, use of basic diagnostic tools, testing equipment to detect decay, disease and scope of tree problems, factors affecting the likelihood of tree failure, use of diagnostic tools
• computations and estimating tree dimensions and their relevance to tree assessment, including: tree height and spread, trunk circumference, DBH, diameter at ground level
• assessing structure and symmetry of the canopy, including: symmetrical and asymmetrical canopy structure and consequences on tree stability and health, trunk inclination and calculating the lean, impact of wind loading on trees and tree structures, estimating and calculating wind loading, relationship and responsiveness of form of crown to surrounding trees and structures
• tree age and health issues and their estimation, including: uninodal and multinodal tree species as an indicator of age, growth increments, including bud scars, sympodial growth and flush marks, checking age estimations using documented images
• valuation methods of amenity trees, including: a range of tree valuation methods and their application, legal and statutory controls and protection of trees, indicators of habitat use, ecological value and significance, cultural value and significance, historical value and significance, preservation orders and local environmental protection laws, calculating amenity tree value of individual trees
• visual tree assessment (VTA) techniques and procedures, including: visual indications and symptoms of disease and health issues, tests and checking the extent of disease and health issues, assessment of impact of tree disease and health issues on tree safety, the purpose and use of basic diagnostic tools
• methods of determining and mitigating levels of risk, including: a range of tree risk assessment methods and their application, identification and extent of tree hazards, causes of instability, decay, damage and stress in trees, quantification and qualification of tree risk, risk benchmarks from non-arboricultural activities, controls available to mitigate risks, remedial action of tree problems
• determining the consequence of risk, including: why most likely outcomes are used and not worst case, abbreviated injury index/scale
• possible targets associated with tree risk, including: persons, property, interruptions to community activity, interruptions to services, occupation rates
• tree assessment reporting procedures, including images

Foundation skills

• Writing: Create logical, accurate and succinct reports with recommendations that include complex issues for risks and valuation of trees
• Numeracy: Identify numerical information for use in complex formulae for calculating the value of trees

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 AHCARB513