Arborist
Encyclopedia
Professional
A professional is a person who is paid to undertake a specialised set of tasks and to complete them for a fee. The traditional professions were doctors, lawyers, clergymen, and commissioned military officers. Today, the term is applied to estate agents, surveyors , environmental scientists,...
in the practice of arboriculture
Arboriculture
Arboriculture is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. It is both a practice and a science....
, which is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. Arborists generally focus on the health and safety of individual plants and trees, rather than managing forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s (the domains of Forestry
Forestry
Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...
and Silviculture
Silviculture
Silviculture is the practice of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values. The name comes from the Latin silvi- + culture...
) or harvesting wood. An arborist's scope of work is therefore distinct from that of either a forester
Forester
250px|thumb|right|Foresters of [[Southern University of Chile|UACh]] in the [[Valdivian forest]]s of San Pablo de Tregua, ChileA forester is a person who practices forestry, the science, art, and profession of managing forests. Foresters engage in a broad range of activities including timber...
or a logger
Lumberjack
A lumberjack is a worker in the logging industry who performs the initial harvesting and transport of trees for ultimate processing into forest products. The term usually refers to a bygone era when hand tools were used in harvesting trees principally from virgin forest...
, though the professions share much in common.
Scope of work
Arborists 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. When personal safety is an issue, or the tree is being removed, arborists 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 arborist's work may involve very large and complex trees, or ecological communities
Biocoenosis
A biocoenosis , coined by Karl Möbius in 1877, describes the interacting organisms living together in a habitat . This term is rarely used in English, as this concept has not been popularized in Anglophone countries...
and their abiotic components
Abiotic components
In biology and ecology, abiotic components are non-living chemical and physical factors in the environment which affect ecosystems. Abiotic phenomena underlie all of biology. Abiotic factors, while generally downplayed, can have enormous impact on ramonds evolution...
in the context of the landscape ecosystem
Landscape ecology
Landscape ecology is the science of studying and improving relationships between urban development and ecological processes in the environment and particular ecosystems...
. 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
Phytopathology
Plant pathology is the scientific study of plant diseases caused by pathogens and environmental conditions . Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants...
or parasitism
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
; preventing or interrupting grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
or predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
; installing lightning protection; and removing vegetation deemed as hazardous, an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
, a disease vector, or a weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
.
Arborists 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 arborists who climb the trees with ropes, harnesses and other equipment. Lifts and cranes may be used too. The work of all arborists is not the same. Some may just perform consulting; others may perform climbing, pruning and planting: a combination.
Arborist qualifications
Many arborists choose to pursue formal certification, which is available in some countries and varies somewhat by location. An arborist 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.
In Australia arboricultural education and training are streamlined countrywide through a multi-disciplinary vocational education, training, and qualification authority called the Australian Qualifications Framework
Australian Qualifications Framework
The Australian Qualifications Framework provides the hierarchy of educational qualifications in Australia. It is administered nationally by the Australian Government Department of Education, Employment and Workplace Relations. Few qualifications outside the system are accepted by employers or for...
, which offers varying levels of professional qualification.
In France a qualified arborist must hold a Management of Ornamental Trees certificate, and a qualified arborist climber must hold a Pruning and Care of Trees certificate; both delivered by the French Ministry of Agriculture.
In the UK an arborist can gain qualifications up to and including a Masters degree. Generally most arborists only attain chainsaw related safety certificates (NPTCs) and do not progress to higher academic study. Most agricultural colleges offer national certificates, diplomas and some offer foundation, bachelor and masters degrees in arboriculture.
In the USA 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
International Society of Arboriculture
The International Society of Arboriculture is an international non-profit organization headquartered in Champaign, Illinois USA. Its mission statement: "Through research, technology, and education promote the professional practice of arboriculture and foster a greater public awareness of the...
. Other designations include Municipal Specialist, Utility Specialist and Board Certified Master Arborist (BCMA).
Cultural practices
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 bioticBiotic component
Biotic components are the living things that shape an ecosystem. A biotic factor is any living component that affects another organism, including animals that consume the organism in question, and the living food that the organism consumes. Each biotic factor needs energy to do work and food for...
or abiotic causes. Arborists can provide appropriate solutions, such as pruning
Pruning
Pruning is a horticultural practice involving the selective removal of parts of a plant, such as branches, buds, or roots. Reasons to prune plants include deadwood removal, shaping , improving or maintaining health, reducing risk from falling branches, preparing nursery specimens for...
trees for health and good structure, for aesthetic
Aesthetics
Aesthetics is a branch of philosophy dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty. It is more scientifically defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste...
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 arborists 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
Tree topping
Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice include hat-racking, heading, rounding over, and...
, 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
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
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
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
. 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 spraying, soil application, stem injections or spraying. Compacted or disturbed soils can be improved in various ways.
Arborists 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 the late Alex Shigo
Alex Shigo
Alex L. Shigo was a plant pathologist with the United States Forest Service whose studies of tree decay resulted in many improvements to standard arboricultural practices. He travelled and lectured widely to promote understanding of tree biology among arborists and foresters...
, considered one "fathers" of modern arboriculture.
Legal issues for arborists
Depending on the jurisdiction, there may be a number of legal issues surrounding the practices of arborists, 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 quarantineQuarantine
Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. The word comes from the Italian quarantena, meaning forty-day period....
s, and safety of nearby trees.
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
Duty of care
In tort law, a duty of care is a legal obligation imposed on an individual requiring that they adhere to a standard of reasonable care while performing any acts that could foreseeably harm others. It is the first element that must be established to proceed with an action in negligence. The claimant...
. Arborists 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
Vandalism
Vandalism is the behaviour attributed originally to the Vandals, by the Romans, in respect of culture: ruthless destruction or spoiling of anything beautiful or venerable...
. In cities with tree preservation order
Tree preservation order
A Tree Preservation Order or TPO is a part of town and country planning in the United Kingdom. A TPO is made by a Local Planning Authority to protect specific trees or a particular area, group or woodland from deliberate damage and destruction...
s an arborist'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. Homeowners who have entered into contracts with a homeowner's association (see also Restrictive covenant
Restrictive covenant
A restrictive covenant is a type of real covenant, a legal obligation imposed in a deed by the seller upon the buyer of real estate to do or not to do something. Such restrictions frequently "run with the land" and are enforceable on subsequent buyers of the property...
s) may need an arborist'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. Arborists may be consulted in forensic investigations where the evidence of a crime can be determined within the growth rings
Dendrochronology
Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year...
of a tree, for example. Arborists 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
Expert witness
An expert witness, professional witness or judicial expert is a witness, who by virtue of education, training, skill, or experience, is believed to have expertise and specialised knowledge in a particular subject beyond that of the average person, sufficient that others may officially and legally...
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 arborists in order to avoid future difficulties.
Arborist training, reference materials, and continuing education
The study materials considered to be the reference canon for arborists seeking to advance from entry level to mastery of the trade in arboricultural services are the following:- Arboriculture: Integrated Management of Landscape Trees, Brooms, Shrubs, and Vines, 4th edition (Harris et al. ) - the standard text for introductory arboriculture, and the primary reference for working arborists.
- ANSIAmerican National Standards InstituteThe American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
A300 standards for tree care operations (TCIA, all parts) - industry standards. - ANSI Z133.1 standard for tree care operations (ISA) - industry standards.
- ANSI Z60 standard for nursery stock (ANLA) - industry standards.
- Best Management Practices (ISA, all topics)
- Plant Health Care for Woody Ornamentals (Lloyd et al.)
- Abiotic Disorders of Landscape Plants—A Diagnostic Guide (Costello et al.)
- Trees and Development: A Technical Guide to Preservation of Trees During Land Development (Matheny and Clark)
- Manual of Woody Landscape Plants (Dirr)
- An Illustrated Guide to Pruning, 2nd edition (Gilman)
- Principles and Practice of Planting Trees and Shrubs (Watson and Himelick)
- Arborists’ Certification Study Guide (Lilly)
- Plant Physiology (Kozlowski)
- Urban Soils: Applications and Practices (Craul)
- A New Tree Biology (Shigo) - the classic text by the man widely considered the father of modern arboriculture, Alex Shigo.
- The Landscape Below Ground; Parts I and II (Neely and Watson)
- Arboriculture and the Law (Merullo)
- Trees and Building Sites Conference Proceedings (Watson and Neely)
- The Art and Science of Practical Rigging (Donzelli et al.)
- A Photographic Guide to the Evaluation of Hazard Trees in Urban Areas (Matheny and Clark)
- Diseases of Trees and Shrubs (Sinclair et al.)
- Evaluating Tree Defects (Hayes)
- Guide for Plant Appraisal, 9th edition (CTLA)
- Insects That Feed on Trees and Shrubs (Johnson et al.)
- Tree Structure and Mechanics Conference Proceedings: How Trees Stand Up and Fall Down (Smiley et al.)
- Journal of Arboriculture - (academic research periodical.)
- Pesticide information: www.greenbook.net and www.pesticideinfo.org
- Urban Forestry: Planning and Managing Urban Greenspaces (Robert Miller)
- Natural Disaster Damage to vegetation
Other significant study materials and references for arborists include:
- USDA Soil Surveys
- Soil Science (Hausenbuiller)
- Urban Soil in Landscape Design (Craul)
- Built Environment (Bartuska)
- Design with Nature (McHargIan McHargIan L. McHarg was born in Clydebank, Scotland and became a landscape architect and a renowned writer on regional planning using natural systems. He was the founder of the department of landscape architecture at the University of Pennsylvania in the United States. His 1969 book Design with Nature...
) - Principles and Applications of Soil Microbiology (Sylvia et al.)
- The Biology of Symbiotic Fungi (Cooke)
- Mycology - Plant Pathology Internet Guide Book (Kraska)
- Forest Entomology: Ecology and Management (Coulson & Witter)
- Plants of the Pacific Northwest (Pojar), or similar local reference
- Trees of Seattle (Jacobson), or similar local reference
- Natural Vegetation of Oregon and Washington (Franklin), or similar local reference
- The Use and Significance of Pesticides in the Environment (McEwen)
- The Body Language of Trees (Mattheck)
- Trees (Coombes)
- Wild Neighbors: The Humane Approach to Living with Wildlife (HSUSHumane Society of the United StatesThe Humane Society of the United States , based in Washington, D.C., is the largest animal advocacy organization in the world. In 2009, HSUS reported assets of over US$160 million....
) - IPM World Textbook (Radcliff, online)
Arborist organizations
- The Tree Care Industry AssociationTree Care Industry AssociationFounded in 1938, the Tree Care Industry Association, formerly the National Arborist Association, is a US public and professional resource organization on trees and arboriculture....
, formerly the National Arborist Association, is a public and professional non-profit organization for the arboriculture field. It has more than 2,000 member companies representing over a dozen countries. TCIA's Accreditation program certifies that tree care companies that have been inspected and accredited based on adherence to industry standards for performance and safety; maintenance of trained, professional staff; and dedication to ethics and quality in business practices. In addition, they provide safety and educational programs, guidelines for tree service operations, ANSI A300 tree pruning standards, and consumer resources. - The International Society of ArboricultureInternational Society of ArboricultureThe International Society of Arboriculture is an international non-profit organization headquartered in Champaign, Illinois USA. Its mission statement: "Through research, technology, and education promote the professional practice of arboriculture and foster a greater public awareness of the...
, a non-profit organization, maintains a list of ISA Certified ArboristsCertified arboristThe Certified Arborist credential identifies professional arborists who have a minimum of three years' full-time experience working in the professional tree care industry and who have passed an extensive examination covering all facets of arboriculture. The of the started the certification...
who have passed a written exam and demonstrated a basic level of knowledge in arboriculture. There are also additional classifications of certified arborists with Certified Arborist/Utility Specialist for those who work near power lines, and Certified Arborist/Municipal Specialist for those who deal mostly with community trees. Other certifications exist for Certified Tree Workers, and the highest level of certification, the Board Certified Master Arborist. - The American Society of Consulting Arborists is an organization whose membership is exclusive to those with either a certain level of industry experience, plus higher educational experience or continuing education; some members may achieve a higher status by fulfilling the requirements to become a Registered Consulting Arborist. Consulting arborists generally specialize in the areas of ethics, law, land planning and development, and tree valuation, among others. Consulting arborists are often called on for legal testimony and report writing in various instances where a particular authority on trees is necessary for consequent actions.
- In the UK, the principal organisation representing arborists is the Arboricultural Association. The association maintain a register of consultants who have demonstrated a high level of technical arboricultural knowledge, and operate an Approved Contractor scheme. This scheme assesses both the technical competence and business practices of arboricultural contractors.
- The European Arboricultural CouncilEuropean Arboricultural CouncilThe European Arboricultural Council based in Bad Honnef, Germany is a forum where delegates from a wide range of arboricultural organizations throughout Europe meet. The goal of the EAC is to elevate the status and to raise the professional level of competence within arboriculture...
is a European group of arboriculture organizations from various countries. - Plant AmnestyPlant AmnestyPlant Amnesty is a non-profit education and advocacy group based in Seattle, Washington.Plant Amnesty was founded by arborist Cass Turnbull on October 22, 1987, as a mock protest group intended to educate the public about the problems associated with pruning techniques which are biologically...
is a public education and advocacy group, based in Seattle, dedicated to promoting proper pruning methods. Founded in 1987, Plant Amnesty became an international resource for arborists and their clients in the mid-1990s.
Arborists in literature
The protagonist in Italo Calvino's novel 'The Baron in the Trees' leaves life on the ground as a boy and spends the rest of his life swinging from tree to tree in the Italian countryside. As a young man he helps the local fruit farmers by pruning their trees. yep--174.20.62.160 (talk) 23:37, 18 November 2011 (UTC)BiggieNotable arborists
Some noteworthy arborists include:- Francis A. BartlettFrancis A. BartlettFrancis A. Bartlett, an eminent dendrologist, graduated from Massachusetts Agricultural College, now the University of Massachusetts, in 1905 . Dr...
- founded the world’s leading scientific tree and shrub care company in 1907. - Franz Borsova - co-founder of the National Arborists Association of Australia.
- John ChapmanJohnny AppleseedJohnny Appleseed , born John Chapman, was an American pioneer nurseryman who introduced apple trees to large parts of Ohio, Indiana, and Illinois...
- pioneering U.S. frontier nurseryman and orchardist, commonly known as Johnny Appleseed. - Richard Essam - head of the Ontario Union of Arborists and Loggers.
- Sebastian JungerSebastian JungerSebastian Junger is an American author, journalist and documentarian, most famous for the best-selling book The Perfect Storm: A True Story of Men Against the Sea, his award-winning chronicle of the war in Afghanistan in the 2010 movie Restrepo, and his 2010 book War.-Background:Junger was born...
- author of Perfect Storm and War, before becoming a journalist, was an arborist in Massachusetts. - Chuck LeavellChuck LeavellChuck Leavell is an American pianist and keyboardist, who was a member of The Allman Brothers Band throughout the height of their popularity, a founding member of the jazz-rock combo Sea Level, a frequently-employed session musician, and later, the keyboardist for Eric Clapton and The Rolling...
- two-time recipient of the Georgia Tree Farmer of the Year award, and author of the children's book, The Tree Farmer. In 2006 Leavell was appointed by Governor Sonny PerdueSonny PerdueGeorge Ervin "Sonny" Perdue III, was the 81st Governor of Georgia. Upon his inauguration in January 2003, he became the first Republican governor of Georgia since Benjamin F. Conley served during Reconstruction in the 1870s....
to the Georgia Land Conservation Council. He is also an accomplished jazz pianist and keyboardist for the Rolling StonesThe Rolling StonesThe Rolling Stones are an English rock band, formed in London in April 1962 by Brian Jones , Ian Stewart , Mick Jagger , and Keith Richards . Bassist Bill Wyman and drummer Charlie Watts completed the early line-up...
. - Liam McGough - a contestant on the British version of Big BrotherBig Brother 2007 (UK)Big Brother 2007 was the eighth series of the United Kingdom reality television programme Big Brother, airing on Channel 4, with a number of closely associated programmes also airing on E4....
- Alex ShigoAlex ShigoAlex L. Shigo was a plant pathologist with the United States Forest Service whose studies of tree decay resulted in many improvements to standard arboricultural practices. He travelled and lectured widely to promote understanding of tree biology among arborists and foresters...
- the father of modern arboriculture. - Cass Turnbull - founder of Plant AmnestyPlant AmnestyPlant Amnesty is a non-profit education and advocacy group based in Seattle, Washington.Plant Amnesty was founded by arborist Cass Turnbull on October 22, 1987, as a mock protest group intended to educate the public about the problems associated with pruning techniques which are biologically...
, a non-profit education and advocacy group, and author of pruning and gardening books. - Benjamin WhiteBenjamin WhiteBenjamin White was a U.S. Representative from Maine.Born in Goshen , Maine, White attended the common schools....
- a working arborist until injured in a fall from a tree, Benjamin White became an environmental activist, worked as bosun of the Sea ShepherdSea ShepherdThe Sea Shepherd Conservation Society is a non-profit, marine conservation organization based in Friday Harbor, Washington in the United States. The group uses direct action tactics to protect sealife...
, and created the sea turtle costumes worn at the anti-WTO protestsWTO Ministerial Conference of 1999 protest activityProtest activity surrounding the WTO Ministerial Conference of 1999, which was to be the launch of a new millennial round of trade negotiations, occurred on November 30, 1999 , when the World Trade Organization convened at the Washington State Convention and Trade Center in Seattle, Washington,...
in Seattle during 1999.