Arborist
From Wikipedia, the free encyclopedia
An arborist (or tree surgeon) is a professional who practices arboriculture, the management and maintenance of trees (generally in an urban environment). While trees provide many benefits, they can also be very large, heavy, and complex organisms that require professional monitoring and treatment to ensure they are healthy and safe. An arborist's work may include some or all of the following: planting, pruning, structural support, diagnosis and treatment of diseases, insects, or abiotic disorders, lightning protection, and tree removal. Arborists may also plan, consult, write reports and give legal testimony. While some aspects of this work may be done on the ground or in an office, much of it requires the arborist to physically climb the trees, using ropes, harnesses, and other climbing equipment.
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[edit] Cultural practices
Trees may require pruning to keep them away from wires, fences and buildings, to improve long-term health and/or structure, for aesthetic reasons, and to permit people to walk and sit under them. They might also require other care to improve their chances of survival and longevity, or treatments in response to damage from biotic or abiotic factors. Trees in urban landscape settings are often subject to human disturbances above and below ground, as well as natural disturbances. Timing or methods depend on the species of tree and the purpose of the work. A thorough knowledge of local species and environments is necessary to determine the best practices.
There can be a vast difference in the techniques and practices of professional arborists and those who simply "trim trees". Many common practices of tree workers are considered unacceptable by modern arboriculture standards. One common abuse of trees is a practice called "topping", "lopping", or "hatracking", in which the outer part of the crown or the entire top of the tree is cut off, which has several detrimental effects. When all of the foliage is removed, the tree is left without the ability to produce food through photosynthesis. It must use stored energy to produce a flush of new growth to replace what was removed. The large internodal cuts are much more prone to decay than proper pruning cuts, and the subsequent abundance of sprouts arise around this area of decay, as well as usually being poorly attached, overcrowded, and weaker due to rapid growth.
Pruning should only be done with a specific purpose in mind. Every cut is a wound, and every leaf lost is removal of some amount of photosynthetic ablility. Proper pruning can be very helpful in many ways, but should always be done with the minimum amount of live tissue removed for the individual situation.
In recent years, research has proven that wound dressings such as paint, tar or other coverings are unnecessary and may be harmful to the tree. The coverings may actually encourage the growth of decay-causing fungi. Proper pruning, by cutting the 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 either through spraying (though this can become impossible with very large trees), soil application, or stem injections when necessary. 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 a great deal in technology and sophistication from practices of the past, and more of the current practices are based on knowledge gained through recent research, including the widely respected and intensive work done by the late Alex Shigo, considered to be one of the fathers of modern arboriculture.[citation needed]
[edit] Legal issues in arboriculture
Depending on the jurisdiction, there are a number of legal issues surrounding the practices of arborists and of urban tree management in general, including boundary issues, public safety issues, "heritage" trees of community value; and multiple "neighbor" issues such as ownership, obstruction of views and/or light, impacts of roots across boundaries, nuisance problems, disease or insect quarantines, or safety of nearby trees.
[edit] Arborist organizations
The Tree Care Industry Association, 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 Arboriculture, a non-profit organization, maintains a list of ISA Certified Arborists 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.
The European Arboriculture Council is a European group of arboriculture organizations from various countries.
[edit] External links
- International Society of Arboriculture
- American Society of Consulting Arborists
- Tree Care Industry Association
- Treecaretips.org - tree care info for consumers
- European Arboricultural Council
- Palm&Tree Services - Tips for handymen, videos of arborists at work, scam protection info.
- Treebuzz.com - Discussion forum and source of information for arborists and tree climbers.
- Arboristsite.com - Online forum of arborist and related professions.
- Tree World - International Arborist Forum
- UK Tree Care mailing list - UK centred online discussion forum for arborists.
