Trees are vital to life. They’re the biggest and oldest species on earth—from backyard natives to the towering eucalyptuses found in our parks, trees provide a range of social, economic, health, and environmental benefits.
But to maximise the benefits that trees give us, they need regular professional care and maintenance. Most people have heard of tree surgeons or tree doctors, but fewer people know what an arborist does, and their importance in tree care.
So, what is an arborist? And what does an arborist do?
Arborists or arboriculturists are professionals in the practice of arboriculture, which is the management and care of trees. Arborists typically carry out their job in places where people live, play and work.
Proper tree care is an investment, as trees that are well cared for can add considerable value to a property. Poorly maintained trees can be a liability, and pruning or removing large trees in particular can be dangerous work. Many people work with and around trees. However, arborists are trained, certified and qualified in all aspects of tree maintenance and care, and adhere to the recommended Australian standards.
Arborists offer professional advice on trees to ensure a safe and aesthetically pleasing result. They consider where trees are positioned, the surrounding area, and how to maximise their health. They are also knowledgeable about tree species and how they will react to different types of pruning. Arborists will evaluate the tree from all angles, and ensure that anything they cut won’t jeopardise the safety of the tree, homes, property, or people. They will also ensure regrowth will be strong and healthy and not require constant maintenance.
Depending on their qualifications, arborists offer a variety of services, including:
No – tree loppers “lop” trees by removing their branches and limbs. Due to a lack of training, they often don’t consider a tree’s position, its overall health or how it will regrow. This can result in undermining a tree’s stability and overall structure, or leave it exposed to disease and insect infestation.
Inefficient pruning can also leave tree limbs poorly attached with a higher risk of breaking. It increases the risk of trees “failing” in strong winds or storms, leaving homes and properties vulnerable to damage, and occupants at risk of injury. If an accident happens and the appropriate insurance isn’t in place, a home or property owner may be sued for allowing the work to be undertaken, and fined if the tree lopper is injured.
An arborist’s work may involve working with large and complex trees to ensure they are safe, healthy and meet the needs of property owners or community standards.
Trees in urban landscape settings are often subject to disturbances, whether human or natural, both above and below the ground. However, there is a vast difference between professional arborists who abide by the correct practices and techniques, and inadequately trained tree workers whose job is to trim trees, not realising that they may be disfiguring, damaging, weakening, or even killing the tree.
Arborists can provide appropriate solutions such as pruning trees for health, structure or aesthetic reasons, but there should be a specific purpose in mind. This is because every cut is a wound and every leaf lost is the removal of some of the tree’s photosynthetic potential.
They also perform “crown raising” to permit people to walk under trees, or “crown reduction” to keep trees away from fences, buildings and wires. The methods and timing of treatment depend on the purpose of the work and the species of the tree. Best practices, therefore, involve a knowledge of both botany and the local environment.
Arborists also assist in diagnosing, treating and preventing phytopathology or parasitism, preventing or interrupting predation, and removing vegetation deemed as hazardous.
While some aspects of their work is done in an office, much of it is undertaken using specialised vehicles to access trees, or by tree climbers who use ropes, harnesses and other relevant equipment.
Depending on the location, there are several legal issues surrounding the practices of arborists, including public safety issues, boundary issues, and the community value of heritage trees.
Arborists frequently consult the facts for tree disputes between property owners. This includes the areas of ownership, the obstruction of views, nuisance problems, and the impacts of root systems crossing boundaries. They may also be asked to assess the value of a tree for insurance purposes if the tree has been destroyed, damaged, vandalised, or stolen.
In cities with tree preservation laws, an arborist’s evaluation may be required before a property owner can remove a tree, or to ensure the protection of trees in development plans and during construction operations.
Arborists are engaged by a variety of individuals, business, and institutions, including:
Arborists need to have qualifications to practice arboriculture, and experience working safely around trees. In Australia, arboricultural training is streamlined through a multi-disciplinary vocational training, education and qualification authority known as the Australian Qualifications Framework.
Tree climbers should possess a Certificate III in Arboriculture or higher qualifications. Companies offering these services should also adhere to the Australian Standard Pruning of Amenity Trees AS-4373-2007, and hold Quality Assurance Accredited with full insurances, including Public Liability cover.
Arborists use a “work positioning system” to climb trees, which differs from the harness systems used in rope-access jobs or rock climbing. Every healthy tree can be climbed, however, some trees can be slippery, snappy or prone to releasing resin, making climbing a sticky job! Typical warning signs arborists need to look out for include cracks, termite or ant activity and unusual swelling on a tree’s trunk.
In terms of climbing trees, it is all about basic geometry and physics, particularly with rope angles. This means keeping a rope above their head (not out to the side), so their weight is on their harness rather than the tree. They also work off a high point, which is the highest part of the tree they can safely be attached to.
Arborists use a variety of ropes, pulleys, harnesses, throw-lines and even spurs, but the most common method of climbing is with a prussik. This is a knot or friction hitch used to attach a loop around a rope. Climbers then pull down on the working line and push up on the prussik using a “pull-down, push-up” technique.
Trees accentuate views, provide privacy, reduce glare and noise, and even enhance architecture. They also bring people together for activities like walking and bird watching, and enable children to discover their sense of adventure through climbing.
Trees slow the rate of global warming, provide habitats for wildlife, and reduce flooding and soil erosion. They also serve as windbreaks, provide protection from rainfall, and moderate temperatures by shading areas and reflecting heat upwards from their leaves.
Trees improve air quality, reduce noise pollution, and the calmness we feel when we’re near them can reduce fatigue, stress and even decrease the recovery time after an illness or surgery.
Trees host complex microhabitats and offer food and shelter to a variety of insects, birds, fungi and lichen. The trunks of older trees also provide hollow cover for bats, possums, owls, parrots, snakes and frogs.
Trees can provide shade which lowers the cooling cost of homes, and can also reduce heating costs by acting as windbreaks. Research also shows that organisations benefit from happier, more productive staff if there are trees and parks located close to their working environment.
References
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