TCAA’s Jim McArdle outlines some important obligations and considerations for arborist supervision and different levels of qualification.
Supervision of Level 3 arborists
When looking at a best-practice model, trade arborists don’t need arborist supervision in the general trade area, except where an AQF 5 Project Arborist requires it.
‘Supervision of a trade arborist’ is stated as a requirement in many DAs where the AQF 5 anticipates a difficulty in protecting trees. AQF level 5 is also a level of compliance initiated by the council to advocate for trees’ preservation on the development site, usually ensuring the construction teams follow the arborist’s recommendations.
AS4970 2025 appears to cover operation outside the role of AQF 5 arborist.
My blunt question is, how could an AQF 5 arborist who hasn’t done any tree work be capable of performing the functions outlined in that document?
A difficulty
On a building or development site where there are trees protected under AS4970 – Protection of Trees on Development Sites, the Project Arborist must be AQF Level 5, and it’s that arborist’s responsibility to ensure trees within a Tree Protection Zone (TPZ) are not damaged by the pruning and/or removal of other trees on the site. The pruning or tree removal can be performed by an AQF Level 3 arborist with the appropriate experience in the method used to do the work, whether by climbing, EWP or crane, but the AQF 3 arborist will be directed by the Project Arborist. The Project Arborist may not be associated with, or must be independent of, the company engaged for the tree works.
This may make it difficult to provide suitable serviceability in regional areas.
Important points
Most building sites will have a mandatory site induction by the developer, which all personnel accessing the site must complete. However, the Project Arborist must also conduct a specific Tree Worker Induction. This arborist supervision will include:
• Checking the qualifications of the AQF Level 3 arborist by viewing their TAFE/Registered Training Provider Certificate of Completion and their years of experience
• Checking the relevant high-risk licences – EWP, crane, and dogman/rigger’s ticket where required
• A safety check on the AQF Level 3 arborist’s climbing and rigging equipment (not usually the role of AQF 5)
• Where a woodchipper is used, check the competence and experience of the ground crew (not usually the role of AQF 5)
• All workers must wear the appropriate Personal Protection Equipment (PPE), including head protection, hearing protection, eye protection and safety boots. (not usually the role of AQF 5). Utilising safety red hats for the dropzone and ensuring the work area is defined with designated witch’s hats and non-inducted tree workers are excluded. This would also include bystanders, the client, officials, media and all other non-inducted persons
• The company providing the Level 3 Arborist, machinery and ground crew must present its Work Cover, Liability and Machinery Insurance Certificate of Currency (CoC) to the Project Arborist prior to work commencing, and this must be checked with the PCB (persons conducting business)
• If the Level 3 arborist is an independent contractor, he or she must produce their insurances prior to commencing, and this must be checked with the PCB
• All tree workers must be made aware of the current Amenity Tree Industry Code of Practice issued by the relevant state government. In NSW this is Safework NSW
• Complete a Safe Work Method Statement (SWMS) and ensure the AQF level 3 arborist and all tree workers are aware of the standard operating procedures contained in the SWMS, and all workers have read and signed the document
• The SWMS must contain a Tree Access Plan by the AQF level 3 arborist detailing the method used to access the tree. If climbing is the preferred method, a pre-climb risk assessment is required and must be approved by the Project Arborist. This assessment can be requested by the AQF 5
• If a protected tree is being pruned, climbing spikes are not to be used
• The SWMS should contain a completed aerial rescue plan with urgent contact numbers for the nominated Rescue Climber (if one is not on site), ambulance, fire brigade and local power authority if power lines are within the Tree Works Operational Area (TWOA)
• If other personnel are on the site, the TWOA should be isolated
• If a crane is being used, the AQF Level 3 arborist must have the required qualification mandated by the relevant state work-safety authority. So must the AQF 5 if supervision is required
• Where a crane is being used, a Loading Unloading Exclusion Zone (LUEZ) must be established where the crane is lowering the limb/s. Only the qualified person releasing the chains from the limb or log is allowed to be in the LUEZ until the crane has moved the lifting chains clear of the zone
• The final Risk Assessment (JSRA) in the SWMS should have all risks reduced to ALARP status where possible
• A Blood Alcohol Content (BAC) breath test or prohibited-drug test may be part of an induction. Any person registering positive on either test will be barred from working and leave the site immediately.
Essentials
All tree-industry workers should be covered by a Fitness to Work policy that includes fatigue management. Workers, both in the tree and on the ground, must be aware of their level of fatigue, particularly in relation to dehydration on hot days. Ample water and electrolyte additives must be available.
Regular work breaks are to be taken. These need not be at fixed intervals, but as the opportunity arises. The time between finishing one tree and commencing another would be a good example.
On-site communications
Tree-work sites are necessarily noisy. Chainsaws, wood chippers and other machinery are often running simultaneously. Workers are required to wear hearing protection, so sometimes communication is difficult.
Radio communication between the Project Arborist and the Level 3 arborist in the trees is the best method of voice communication. This is also the case between a crane operator and a climber. Helmets wired for radio communication are the ideal method, however these are expensive and few work crews will have access to them.
For ground crew, hand signals work best, however it’s essential the person sending the signal has the attention of the receiver of the signal.
Protected trees
Trees within the Tree Protection Zone (TPZ) must not be damaged during the tree works. If a protected tree is being pruned the Level 3 arborist must work in accordance with AS4373 – Pruning of Amenity Trees and AS4970 – Protection of Trees on Development Sites. Climbing spikes are not to be used, and when the tree is to be preserved and protected, care must be taken when lowering and dropping pruned branches to ensure the remaining canopy isn’t damaged.
Where damage does occur, the Project Arborist must compile a damage report, including photos, and list the remedial action taken. In certain cases, if the tree can’t be maintained as viable, the report will become a part of the amended Section 4.55 Arboricultural Impact Assessment (AIA) on the development site.
Relevant authority
The Project Arborist on site during the tree works should be the same person who conducted the original AIA and established the Tree Protection Zone/s. This Project Arborist is the relevant authority on site, handling arborist supervision, and with regards to any protected trees, and this authority can only be overridden (usually) by the Site Safety Officer of the Developer if the SSO determines the overall safety of the site is being compromised.
Hierarchy of control
Methods of access can vary according to conditions, and usually the hierarchy of control indicates use of access by EWP, crane-manbox, and climbing as a last resort. This needs to be included in SWMS and further stated if site specific conditions are constraining the work.
In sensitive forest areas, canopy and riparian corridors need protection. Trees near power lines may require large cranes, EWPs and workers aloft for various tasks. Referring to access and types of methodology to state the workflow and drop points, hitch points, removal, hoarding, ground protection, canopy branch or stem protection can usually be enforced with a stop-work order.
A great place to be
It reads as though there’s a great deal of responsibility relating to arborist supervision for an AQF 5 Project Arborist, and so there is.
But what’s the reward with supervising? Being part of the team, the personalities, the teamwork and, of course, being in a privileged space where we can pass on skills and trusted arboristry methods.
Contact the TCAA via the website: tcaa.com.au.