Arborist
An arborist, 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.
[citation needed] Arborists generally focus on the health and safety of individual plants and trees, rather than managing forests or harvesting wood (silviculture or forestry).
[citation needed] An arborist's work may involve very large and complex trees, or ecological communities and their abiotic components in the context of the landscape ecosystem.
Arborists 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 consultation and report writing.
An arborist who holds certification in one or more disciplines may be expected to participate in rigorous continuing education requirements to ensure constant improvement of skills and techniques.
[citation needed] In the US, a Certified Arborist (CA) is a professional who has over three years of documented and verified experience and has passed a rigorous written test from the International Society of Arboriculture.
[citation needed] In Canada, there are provincially governed apprenticeship programs that allow arborists' to work near power lines upon completion.
Some commonly offered "services" are considered unacceptable by modern arboricultural standards and may seriously damage, disfigure, weaken, or even kill trees.
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.
Proper pruning, by cutting through branches at the right location, can do more to limit decay than wound dressing [10] Chemicals can be applied to trees for insect or disease control through soil application, stem injections or spraying.
[citation needed] Arborists can also assess trees to determine the health, structure, safety or feasibility within a landscape and in proximity to humans.
Many current practices are based on knowledge gained through recent research, including that of Alex Shigo, considered one "father" of modern arboriculture.
[citation needed] Arborists 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.
Carrying out work on protected trees and hedges is illegal without express permission from local authorities,[16] and can result in legal action including fines.
