Tree Doctor

A Tree Doctor, tree surgeon, or (less commonly) arboriculturist, is a professional in the practice of arboriculture, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.

Tree doctors generally focus on the health and safety of individual plants and trees, rather than managing forests (the domains of forestry and silviculture) or harvesting wood. A tree doctor’s scope of work is therefore distinct from that of either a forester or a logger, though the professions share much in common.

The following are signs that a tree should be examined by a Tree Doctor Specialist:

• Leaves appearing later than usual
• Leaves falling off earlier than normal
• Discolored leaves or leaves without veins or with odd nodules
• Bark that forms bumps or is split, cracked or peeling
• Dead branches near the top of the tree
• Fungus growing around the trunk, mushrooms forming around roots or twigs growing from the trunk

A tree doctor may conduct a variety of tests to determine the best course of action, including a soil analysis. For proper growth, trees need soil that contains a particular balance of 15 mineral elements. The tree doctor may also test soil acidity or alkalinity. Fertilizer or soil amendments may make the soil a healthier tree environment.

Sometimes, no treatment is enough to save a tree. Reasons for removing one include serious root or trunk problems or structural defects that could cause the tree to topple in a high wind.

If you’re thinking of hiring a tree doctor, contact well-reviewed local tree service companies and ask if they have a tree doctor on staff. Consider the individual’s level of education, certification and experience, as well as the company’s online reputation with other consumers.

A tree doctor, tree surgeon, or (less commonly) arboriculturist, is a professional in the practice of arboriculture, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.

Tree doctors generally focus on the health and safety of individual plants and trees, rather than managing forests or harvesting wood (forestry or silviculture). A tree doctor’s scope of work is therefore distinct from that of either a forester or a logger.

Scope of work

In order for tree doctors to work near power wires, either additional training is required or they need to be certified as a Qualified Line Clearance Tree doctor or Utility Tree doctor (there may be different terminology for various countries). There is a variety of minimum distances that must be kept from power wires depending on voltage, however the common distance for low voltage lines in urban settings is 10 feet (about 3 metres).

Tree doctors who climb (as not all do) can use a variety of techniques to ascend into the tree. The least invasive, and most popular technique used is to ascend on rope. There are two common methods of climbing, Single Rope System (SRS) and Moving Rope System (MRS). When personal safety is an issue, or the tree is being removed, tree doctors may use ‘spikes’, (also known as ‘gaffs’ or ‘spurs’) attached to their chainsaw boots with straps to ascend and work. Spikes wound the tree, leaving small holes where each step has been.

An tree doctor’s work may involve very large and complex trees, or ecological communities and their abiotic components in the context of the landscape ecosystem. These may require monitoring and treatment to ensure they are healthy, safe, and suitable to property owners or community standards. This work may include some or all of the following: planting; transplanting; pruning; structural support; preventing, or diagnosing and treating phytopathology or parasitism; preventing or interrupting grazing or predation; installing lightning protection; and removing vegetation deemed as hazardous, an invasive species, a disease vector, or a weed.

Tree doctors may also plan, consult, write reports and give legal testimony. While some aspects of this work are done on the ground or in an office, much of it is done by tree doctors who perform tree services and who climb the trees with ropes, harnesses and other equipment. Lifts and cranes may be used too. The work of all tree doctors is not the same. Some may just provide a consulting service; others may perform climbing, pruning and planting: whilst others may provide a combination of all of these services.

Qualifications

Tree doctors gain qualifications to practice arboriculture in a variety of ways and some tree doctors are more qualified than others. Experience working safely and effectively in and around trees is essential. Tree doctors tend to specialize in one or more disciplines of arboriculture, such as diagnosis and treatment of pests, diseases and nutritional deficiencies in trees, climbing and pruning, cabling and lightning protection, or perhaps consultation and report writing. All these disciplines are related and some tree doctors are very well experienced in all areas of tree work, but not all tree doctors have the training or experience to properly practice every discipline.

Tree doctors choose to pursue formal certification, which is available in some countries and varies somewhat by location. An tree doctor who holds certification in one or more disciplines may be expected to participate in rigorous continuing education requirements to ensure continuous improvement of skills and techniques.

Cultural practices

Tree doctors may use specialized vehicles to gain access to trees, such as this Unimog equipped with a power take-off driven wood chipper.

Trees in urban landscape settings are often subject to disturbances, whether human or natural, both above and below ground. They may require care to improve their chances of survival following damage from either biotic or abiotic causes. Tree doctors can provide appropriate solutions, such as pruning trees for health and good structure, for aesthetic reasons, and to permit people to walk under them (a technique often referred to as “crown raising”), or to keep them away from wires, fences and buildings (a technique referred to as “crown reduction”). Timing and methods of treatment depend on the species of tree and the purpose of the work. To determine the best practices, a thorough knowledge of local species and environments is essential.

There can be a vast difference between the techniques and practices of professional tree doctors and those of inadequately trained tree workers who simply “trim trees”. Some commonly offered “services” are considered unacceptable by modern arboricultural standards and may seriously damage, disfigure, weaken, or even kill trees. One such example is tree topping, lopping, or “hat-racking”, where entire tops of trees or main stems are removed, generally by cross-cutting the main stem(s) or leaders, leaving large unsightly stubs. Trees that manage to survive such treatment are left prone to a spectrum of detrimental effects, including vigorous but weakly attached regrowth, pest susceptibility, pathogen intrusion, and internal decay.

Pruning should only be done with a specific purpose in mind. Every cut is a wound, and every leaf lost is removal of some photosynthetic potential. Proper pruning can be helpful in many ways, but should always be done with the minimum amount of live tissue removed.

In recent years, research has proven that wound dressings such as paint, tar or other coverings are unnecessary and may harm trees. The coverings may encourage growth of decay-causing fungi. Proper pruning, by cutting through branches at the right location, can do more to limit decay than wound dressing.

Chemicals can be applied to trees for insect or disease control through soil application, stem injections or spraying. Compacted or disturbed soils can be improved in various ways.

Tree doctors can also assess trees to determine the health, structure, safety or feasibility within a landscape and in proximity to humans. Modern arboriculture has progressed in technology and sophistication from practices of the past. Many current practices are based on knowledge gained through recent research, including that of Alex Shigo, considered one “father” of modern arboriculture.

Legal issues

Depending on the jurisdiction, there may be a number of legal issues surrounding the practices of tree doctors, including boundary issues, public safety issues, “heritage” trees of community value; and “neighbor” issues such as ownership, obstruction of views, impacts of roots crossing boundaries, nuisance problems, disease or insect quarantines, and safety of nearby trees.

Tree doctors are frequently consulted to establish the factual basis of disputes involving trees, or by private property owners seeking to avoid legal liability through the duty of care. Tree doctors may be asked to assess the value of a tree in the process of an insurance claim for trees damaged or destroyed, or to recover damages resulting from tree theft or vandalism. In cities with tree preservation orders an tree doctor’s evaluation of tree hazard may be required before a property owner may remove a tree, or to assure the protection of trees in development plans and during construction operations. Carrying out work on protected trees and hedges is illegal without express permission from local authorities, and can result in legal action including fines. Homeowners who have entered into contracts with a homeowner’s association may need an tree doctor’s professional opinion of a hazardous condition prior to removing a tree, or may be obligated to assure the protection of the views of neighboring properties prior to planting a tree or in the course of pruning. Tree doctors may be consulted in forensic investigations where the evidence of a crime can be determined within the growth rings of a tree, for example. Tree doctors may be engaged by one member of a dispute in order to identify factual information about trees useful to that member of the dispute, or they can be engaged as an expert witness providing unbiased scientific knowledge in a court case. Homeowners associations seeking to write restrictive covenants, or legislative bodies seeking to write laws involving trees, may seek the counsel of tree doctors in order to avoid future difficulties.