Why professional standards matter to arborists

Standards like ANSI A300 help tree care professionals provide the best care for trees while meeting clients’ needs safely
Standards like ANSI A300 help tree care professionals provide the best care for trees while meeting clients’ needs safely.

People have been planting, pruning and fertilizing trees throughout recorded history. For as many years as this has been done, almost as many methods and techniques have been applied.

Let’s taking pruning as an example. For decades, tree “topping,” which is defined as cutting back a tree to a predetermined crown height limit, was an accepted pruning practice. Topping was commonly done by both tree and utility line clearance companies. No one questioned the validity of this pruning method because it was so widely done. Then a man by the name of Dr. Alex Shigo, a USDA Forest Service scientist working in the Northeast, discovered how trees react to being drilled, pruned or otherwise injured. His published studies about a tree’s reaction to these outside influences revolutionized forestry and arboriculture. Today, all books on pruning are solidly based on the science of tree biology and Dr. Shigo’s groundbreaking work.

[Related: Why diversity matters to trees]

In the early ’90s, scientists, consultants, educators, tree care companies and organized tree groups got together under the auspices of the American National Standards Institute (ANSI). Their goals were to provide definitions and science-based procedures to accepted tree practices. They developed standards that now comprise “ANSI A300 Tree Care Operations: Standard Practices for Tree, Shrub and Other Woody Plant Maintenance.” There are currently 10 parts to the A300 standards: Pruning, Soil Management, Supplemental Support Systems, Lightning Protection Systems, Management, Planting and Transplanting, Integrated Vegetation Management, Root Standard Management, Tree Risk Assessment and Integrated Pest Management. These standards are used to develop written specifications for work assignments, and are periodically reviewed to address concerns or changes in the science-based information. They are designed to promote proven tree care practices, enhance communication between all parties involved, reduce miscommunication between these same parties, educate, facilitate contract fulfillment and reduce exposure to liability.

The standards for each part of the A300 are standalone documents. However, they are usually paired and sold with the Best Management Practices (BMP) for that particular standard. These BMP booklets were developed for the purpose of interpreting tree care standards and providing guidelines of practices for arborists, tree workers and people who employ their services. The International Society of Arboriculture (ISA) has created a BMP for each of the 10 parts of the ANSI A300 standards. Some of these BMPs are now even into their third published edition, having been peer-reviewed at least twice. Additionally, there are Spanish versions of the more popular BMPs on tree pruning, utility pruning, planting and integrated vegetation management.

The A300 standards, paired with the appropriate BMPs, facilitate understanding between all parties concerned with proper tree care work. They also discredit unacceptable practices like tree topping and planting container trees with girdling roots still intact. Thanks to these standards, today there is no excuse for not knowing proper tree care methods.

Vince Urbina is an urban & community forestry specialist for the Colorado State Forest Service. His work and tree interests take him all over the Rocky Mountain Region teaching, sharing and mentoring others interested in trees.

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