Application
This unit of competency describes the skills and knowledge required to analyse the edaphic interactions of trees and structures.
This unit applies to individuals with advanced theoretical and technical knowledge and skills for professional or highly skilled work and/or further learning in one or more disciplines or areas of practice. This unit applies to individuals with advanced cognitive, technical and communication skills to provide specialist advice, analyse, generate and transmit solutions to complex problems, and to demonstrate autonomy, well-developed judgement, adaptability and responsibility as a practitioner or learner.
The role involves the self-directed application of knowledge in tree anatomy, physiology and the edaphic environment with substantial depth in areas such as tree failures and biomechanics in the built environment.
No occupational licensing, legislative or certification requirements are known to apply to this unit at the time of publication.
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 soil attributes | 1.1 Research repose angle of soil materials 1.2 Research soil plasticity 1.3 Measure soil moisture content and field capacity of soil 1.4 Research the effects of soil moisture on soil cohesion and plasticity 1.5 Research modes of soil liquefaction 1.6 Determine soil texture 1.7 Assess level of soil cohesion 1.8 Determine shear strength of the soil of concern 1.9 Research load bearing capacity of soil of concern 1.10 Determine mass of the soil plate |
2. Determine root attributes | 2.1 Determine root morphology, division and distribution 2.2 Determine amount of buttressing of tree 2.3 Determine species development of tap root system 2.4 Research identifying anatomical features of tree roots 2.5 Identify tree roots based on anatomical features |
3. Calculate forces from roots | 3.1 Research, experimentally model or demonstrate forces and pressures exerted into or through the soil, directly and indirectly by trees 3.2 Estimate and measure dimensions of roots exerting a force on a structure of concern 3.3 Calculate total surface area of the roots exerting a force on a structure of concern 3.4 Calculate force exerted by roots per unit of surface area of structure 3.5 Calculate total force exerted by roots of a given surface area |
4. Determine structure attributes | 4.1 Measure and determine volume of structure of concern 4.2 Research and calculate mass of the structure and adjacent structures 4.3 Consider the impact of gravity on mass 4.4 Determine affect of leverage on the forces exerted by tree roots onto structure of concern |
5. Define the root-soil matrix factors for root/soil breakage | 5.1 Determine factors of root–soil matrix interactions 5.2 Consider area of contact between root and soil 5.3 Consider elasticity, tensile strength and breaking stress of roots 5.4 Investigate root cross-sectional morphology 5.5 Assess extent of root plate damage, deficiencies or defects 5.6 Estimate impact of static and dynamic testing for root plate stability 5.7 Evaluate the likelihood of root failure by root breakage 5.8 Evaluate the likelihood of anchorage failure by soil breakage or slippage |
6. Research structural engineering solutions | 6.1 Research and consider effects of increasing mass 6.2 Research and consider methods for, and effects of, increasing the modus of rupture 6.3 Research and consider effects of use of curved structures 6.4 Research and consider effects of soil mass and friction 6.5 Research and consider effects of use of anchors, braces and props 6.6 Compile a portfolio of above research including personal annotations and calculations |
7. Prepare stability and expert witness reports | 7.1 Prepare report on likelihood of tree causing damage to structure of concern including all test results, assumptions and calculations 7.2 Provide design suggestions to mitigate likelihood of damage to a similar replacement structure 7.3 Prepare report on relative stability of tree as a result of a defective or damaged root plate 7.4 Provide design suggestions to mitigate likelihood of whole tree failure as a result of defective or damaged root plate 7.5 Prepare expert witness report on harm by roots on structures; or on stability of tree with a defective or damaged root plate, as required |
8. Facilitate teamwork | 8.1 Review construction and engineering language terminology 8.2 Discuss installation and protection measures to non-arboricultural project personnel 8.3 Resolve issues in construction and engineering terminology 8.4 Communicate in the language, concepts, basic science and technology of construction, architecture and engineering allied professions |
Evidence of Performance
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:
researching repose angle of soil materials
researching soil plasticity
measuring soil moisture content and field capacity of soil
researching the effects of soil moisture on soil cohesion and plasticity
researching modes of soil liquefaction
determining soil texture
assessing level of soil cohesion
determining shear strength of the soil of concern
researching load bearing capacity of soil of concern
determining mass of the soil plate
determining root morphology, division and distribution
determining amount of buttressing of tree
determining species development of tap root system
researching identifying anatomical features of tree roots
identifying tree roots based on anatomical features
researching, experimentally modelling or demonstrating forces and pressures exerted into or through the soil, directly and indirectly by trees
estimating and measuring dimensions of roots exerting a force on a structure of concern
calculating total surface area of the roots exerting a force on a structure of concern
calculating force exerted by roots per unit of surface area of structure
calculating total force exerted by roots of a given surface area
measuring and determine volume of structure of concern
researching and calculate mass of the structure and adjacent structures
considering the impact of gravity on mass
determining affect of leverage on the forces exerted by tree roots onto structure of concern
determining factors of root–soil matrix interactions
considering area of contact between root and soil
considering elasticity, tensile strength and breaking stress of roots
investigating root cross-sectional morphology
assessing extent of root plate damage, deficiencies or defects
estimating impact of static and dynamic testing for root plate stability
evaluating the likelihood of root failure by root breakage
evaluating the likelihood of anchorage failure by soil breakage or slippage
researching and considering effects of increasing mass
researching and considering methods for, and effects of, increasing the modus of rupture
researching and considering effects of use of curved structures
researching and considering effects of soil mass and friction
researching and considering effects of use of anchors, braces and props
compiling a portfolio of above research including personal annotations and calculations
preparing report on likelihood of tree causing damage to structure of concern including all test results, assumptions and calculations
providing design suggestions to mitigate likelihood of damage to a similar replacement structure
preparing report on relative stability of tree as a result of a defective or damaged root plate
providing design suggestions to mitigate likelihood of whole tree failure as a result of defective or damaged root plate
preparing expert witness report on harm by roots on structures; or on stability of tree with a defective or damaged root plate, as required
reviewing construction and engineering language terminology
discussing installation and protection measures to non-arboricultural team members
resolving issues in construction and engineering terminology
communicating in the language, concepts, basic science and technology of construction, architecture and engineering allied professions.
Evidence of Knowledge
The candidate must demonstrate knowledge of:
repose angle of soil materials
soil plasticity
soil moisture content
field capacity of soil
effects of soil moisture on soil cohesion and plasticity
modes of soil liquefaction
soil texture
soil cohesion
shear strength of the soil
load bearing capacity
mass of soil plate
root morphology
root division
root distribution
buttressing
species development of tap root systems
anatomical features of tree roots
identification of tree roots based on anatomical features
research, experimental modelling and demonstration methods
forces and pressures exerted into or through the soil, directly and indirectly by trees
estimation and measurement of dimensions of roots exerting a force on a structure
calculation of the total surface area of the roots exerting a force on a structure
calculation of the force exerted by roots per unit of surface area of structure
calculation of the total force exerted by roots of a given surface area
measurement of volume of structures
calculation of the mass of structures
impact of gravity on mass
affect of leverage on the forces exerted by tree roots onto structure
factors of root–soil matrix interactions
area of contact between root and soil
elasticity of roots
tensile strength of roots
breaking stress of roots
root cross-sectional morphology
extent of root plate damage
extent of root plate deficiencies
extent of root plate defects
impact of static and dynamic testing for root plate stability
likelihood of root failure by root breakage
likelihood of anchorage failure by soil breakage or slippage
effects of increasing mass
effects of use of curved structures
effects of soil mass and friction
effects of, increasing the modus of rupture
effects of use of anchors, braces and props
portfolio of research
personal annotations and calculations
report preparation
test results and assumptions
relative stability of tree
whole tree failure
design suggestions for mitigation of damage and whole tree failure
harm by roots on structures
expert witness reports
expert witness report on harm by roots on structures
construction language terminology
engineering language terminology
installation and protection measures
concepts, basic science and technology of structural engineering
concepts, basic science and technology of construction
concepts, basic science and technology of architecture.
Assessment Conditions
It is an industry requirement that competency in this unit requires the preparation of a minimum of two (2) different reports:
a report on harm by roots on structures
a report on stability of tree with a defective or damaged root plate
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
diagnostic tools including sounding hammer, trowel, probe, cordless drill
soil testing equipment
digital dissection microscope 10 -100x
compound microscope
microtome, staining and slide mounting equipment
slides and coverslips
temporary/permanent mountant
histochemical stains
materials:
structural damage and stability report
glossary of construction, architecture and engineering terminology
Assessors must satisfy current standards for RTOs in the assessment of arboriculture units of competency.
Assessment must be conducted only by persons who have:
tree biomechanics vocational competencies at least to the level being assessed
current tree biomechanics 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)