Application
This unit of competency describes the skills and knowledge required to examine and assess tree health, age, taxonomy, risk, amenity value and significance and compile a tree assessment report.
This unit applies to individuals with broad theoretical and technical knowledge of a specific area or a broad field of work and learning and cognitive, technical and communication skills to demonstrate autonomy, judgement and defined responsibility in undertaking complex work within broad parameters to provide specialist advice and functions.
The role involves the self-directed application of knowledge with substantial depth in areas such as tree identification, pathology and diagnostics, tree assessment and valuation techniques, tree risk assessment and reporting methods.
Licensing, legislative, regulatory, or certification requirements apply to this unit in some states & territories at the time of publication, and may differ according to jurisdiction. Specific determination should be sought through the relevant State or Territory. Works involving this unit of competency may be subject to local tree protection and preservation laws, and the relevant content of applicable Australian Standards.
Elements and Performance Criteria
Element | Performance criteria |
Elements describe the essential outcomes. | Performance criteria describe the performance needed to demonstrate achievement of the element. |
1. Determine tree survey program requirements | 1.1 Identify scope of survey in accordance with client needs 1.2 Determine client’s risk threshold 1.3 Determine and document procedures for data capture 1.4 Identify, source and record all current data research relevant to survey requirements 1.5 Check equipment for assessing trees and prepare for use 1.6 Select, check and use personal protective equipment |
2. Determine the tree dimensions and structure | 2.1 Plot tree location on a device, drawing or plan of the site 2.2 Determine and record tree dimensions and structure 2.3 Measure tree height, spread and diameter-at-breast height (DBH) 2.4 Examine and record form of tree 2.5 Assess tree for asymmetry of canopy 2.6 Assess if tree has a lean and calculate the lean 2.7 Assess how form of crown relates to or is responsive to surrounding trees and structures 2.8 Determine the potential impact of wind loading of the tree |
3. Record tree taxonomic features | 3.1 Inspect tree and record fruit type and characteristics 3.2 Describe leaf morphology for shape, colour and size 3.3 Examine and record buds, branchlets, branches and bark 3.4 Inspect for and describe trichomes on lamina, petiole and branchlets 3.5 Describe and record floral characteristics of structure of inflorescence, location of the flower, flower colour, details of the flower parts present, absent or modified |
4. Assess tree health issues | 4.1 Examine and record the canopy density and distribution 4.2 Assess recorded leaf colour and size against a healthy specimen 4.3 Assess for the presence of epicormic shoots 4.4 Assess for dead tips or excessive numbers of dead branches 4.5 Examine roots, root crown, stem, branches and canopy for signs of biotic and abiotic disease 4.6 Evaluate and describe symptoms presenting on tree 4.7 Determine how presence of disease might be affecting tree 4.8 Recognise and record wounds to the tree 4.9 Consider size, location and cause of wounds |
5. Assess age of trees and tree parts | 5.1 Determine if species is uninodal or multimodal 5.2 Record the dimensions of the tree 5.3 Examine tree for evidence of growth increments including bud scars, sympodial growth and flush marks 5.4 Estimate average annual increase in diameter of sample of xylem stained as required 5.5 Research historic images of tree or trees of same species in similar environments 5.6 Provide a reasoned estimate of age of tree, tree part or wound |
6. Assess trees for significance | 6.1 Assess tree for indicators of habitat use 6.2 Assess tree for ecological significance 6.3 Assess tree for cultural significance 6.4 Assess tree for historical significance |
7. Assess amenity value of trees | 7.1 Evaluate amenity tree valuation methods 7.2 Consider strengths and weaknesses of each method 7.3 Determine amenity tree valuation method to be used 7.4 Collect and collate appropriate unit values and data 7.5 Calculate and record the amenity value of individual trees |
8. Inspect and assess trees | 8.1 Assess trees to determine their structure and stability 8.2 Give consideration to the tree's age, health, condition, habitat, wind loading, distribution of foliage, wound size and the potential impacts of proposed recommendations 8.3 Use testing equipment, where required, to detect decay, disease and scope of tree problems 8.4 Evaluate visual indications and causes of disease and record results |
9. Carry out risk assessment | 9.1 Use visual tree assessment (VTA) to identify hazards associated with the tree 9.2 Use basic diagnostic tools to confirm the presence and extent of hazards 9.3 Determine level of risk 9.4 Give consideration to qualification and quantification of tree risk 9.5 Compare the risk level against commonly published levels of risk from non-arboricultural activities and items 9.6 Determine controls required to mitigate risks in accordance with the client’s pre-determined threshold 9.7 Document risk controls and recommendations for monitoring and review of risks |
10. Compile a tree assessment report | 10.1 Document diagnosis of tree problems with reference to the anatomy, physiology and pathology of the tree 10.2 Provide and record specific recommendations for remedial action for tree problems 10.3 Produce a tree assessment report that identifies hazardous trees, recommends appropriate remedial action, and determines appropriate risk controls 10.4 Prepare an expert witness statement if required 10.5 Deliver tree assessment report to client |
Evidence of Performance
The candidate must be observed inspecting and assessing a broad range of trees for identification, health, growth habit, structure, stability and indications of disease. The candidate must be assessed on their ability to integrate and apply the performance requirements of this unit in a workplace setting. Performance must be demonstrated consistently over time and in a suitable range of contexts.
The candidate must provide evidence for and demonstrate:
identifying the scope of survey
determining the client’s risk threshold
documentation of the data capture procedures
identifying, sourcing and recording all current data research relevant to survey requirements
checking equipment for assessing trees and prepare for use
selecting, checking and using personal protective equipment
plotting tree locations on a device, drawing or plan of the site
determining the tree dimensions and structure
measuring the tree height, spread and diameter-at-breast height (DBH)
examining and recording form of tree
assessing tree for asymmetry of canopy
assessing if tree has a lean and calculate the lean
assessing how form of crown relates to or is responsive to surrounding trees and structures
determining the potential impact of wind loading of the tree
inspecting tree and record fruit type and characteristics
describing leaf morphology for shape, colour and size
examining and recording buds, branchlets, branches and bark
inspecting for and describing trichomes on lamina, petiole and branchlets
describing and recording floral characteristics of structure of inflorescence, location of the flower, flower colour, details of the flower parts present, absent or modified
examining and record the canopy density and distribution
assessing recorded leaf colour and size against a healthy specimen
assessing for the presence of epicormic shoots
assessing for dead tips or excessive numbers of dead branches
examining roots, root crown, stem, branches and canopy for signs of biotic and abiotic disease
evaluating and describing symptoms presenting on tree
determining how presence of disease might be affecting tree
recognising and recording wounds to the tree
considering size, location and cause of wounds
determining if species is uninodal or multimodal
recording the dimensions of the tree
examining tree for evidence of growth increments including bud scars, sympodial growth and flush marks
estimating average annual increase in diameter of sample of xylem stained as required
researching historic images of tree or trees of same species in similar environments
providing a reasoned estimate of age of tree, tree part or wound
assessing tree for indicators of habitat use
assessing tree for ecological significance
assessing tree for cultural significance
assessing tree for historical significance
evaluating various amenity tree valuation methods
considering strengths and weaknesses of each method
determining amenity tree valuation method to be used
collecting and collating appropriate unit values and data
calculating and recording the amenity value of individual trees
assessing trees to determine their structure and stability
consideration of the tree's age, condition, habitat, wind loading, distribution of foliage, wound size and the potential impacts of proposed recommendations
using testing equipment to detect decay, disease and scope of tree problems
evaluating visual indications of disease and health issues in trees
use of visual tree assessment (VTA) method to identify hazards
use of basic diagnostic tools to confirm the presence and extent of hazards
determining level of risk
giving consideration to qualification and quantification of tree risk
comparing the risk level against commonly published levels of risk from non-arboricultural activities and items
determining controls required to mitigate risks in accordance with the client’s pre-determined threshold
documenting risk controls and recommendations for monitoring and review of risks
documenting diagnoses of tree problems with reference to the anatomy, physiology and pathology of the tree
recording specific recommendations for remedial action for tree problems
producing a tree assessment report that identifies a hazardous tree and contains recommendations for appropriate remedial actions and risk controls
preparing an expert witness statement
use of industry standard terminology to describe arboriculture and the work environment.
Evidence of Knowledge
The candidate must demonstrate knowledge of:
risk thresholds
data capture procedures
survey requirements
tree assessment equipment
plotting methods on devices, drawings and plans
tree morphology attributes: fruit type and characteristics, leaf morphology for shape, colour and size, trichomes on lamina, petiole and branchlets, floral characteristics of structure of inflorescence, location of the flower, flower colour, details of the flower parts present, absent or modified, buds, branchlets, branches and bark
canopy density and distribution
comparison of leaf colour and size against a healthy specimen
epicormic shoots
examination of roots, root crown, stem, branches and canopy for signs of biotic and abiotic disease
disease symptoms
affect of disease on tree
tree dimensions and structure
tree height, spread and diameter-at-breast height (DBH)
form and morphology of tree
symmetry and asymmetry of canopy
calculation of tree lean
relationship of form of crown to surrounding trees and structures
responsiveness of form of crown to surrounding trees and structures
determination the potential impact of wind loading of the tree
tree wound recognition, size, location and cause
uninodal and multimodal tree species
growth increments including bud scars, sympodial growth and flush marks
estimation average annual increase in tree diameter
xylem staining
research of historic images of tree or trees of same species in similar environments
assessment of tree indicators of habitat use
assessment of tree ecological significance
assessment of tree cultural significance
assessment of tree historical significance
evaluation of methods of amenity tree valuation
calculation of amenity tree value of individual trees
tree structure and stability
tree assessment attributes: tree's identification, age, health, condition, habitat, wind loading, distribution of foliage, wound size and the potential impacts of proposed recommendations
testing equipment to detect decay, disease and scope of tree problems
visual indications and symptoms of disease and health issues
tree diseases
visual tree assessment (VTA)
methods of detecting decay and structural defects in trees
causes of instability, decay, damage and stress in trees
use of basic diagnostic tools
identification and extent of tree hazards
methods of determination of levels of risk
quantification and qualification of tree risk
commonly published levels of risk from non-arboricultural activities and items
controls required to mitigate risks in accordance with the client’s pre-determined threshold
diagnoses of tree problems
tree anatomy, physiology and pathology
remedial action of tree problems
production of a tree assessment report that identifies hazardous trees, recommends appropriate remedial action, and determines appropriate risk controls
preparation of an expert witness statement.
Assessment Conditions
Assessment must be demonstrated consistently over time in a suitable range of contexts and have a productivity-based outcome. No single assessment event or report is sufficient to achieve competency in this unit.
Assessment may be conducted in a simulated or real work environment, however determination of competency requires the application of work practices under work conditions.
The mandatory equipment and materials used to gather evidence for assessment include:
equipment:
computer
word processing software
internet connection
digital camera with macro
personal protective equipment (PPE)
diagnostic tools including sounding hammer, trowel, probe, cordless drill
cross-sectioned defects and diseases
soil testing equipment
basic digital dissection microscope 10 -100x
compound microscope
microtome, staining and slide mounting equipment
slides and coverslips
temporary/permanent mountant
histochemical stains
materials:
tree assessment report
tree profile and benefits form
disease profile form
Assessors must satisfy current standards for RTOs in the assessment of arboriculture units of competency.
Assessment must be conducted only by persons who 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
Foundation Skills essential to performance are explicit in the performance criteria of this unit of competency.
Range Statement
Sectors
Arboriculture (ARB)