Who are the Certified Arborists and how are hazard trees assessed?

The Debris Management Task Force (DMTF) prioritizes safety and tree health when assessing hazard trees. To manage this balance, arborists working with our Task force crews are certified, and required to have a professional resume which includes a certification with the International Society of Arboriculture verifying five years of experience in post forest fire assessments as well as a demonstrated understanding of forest management practices.

Think of an arborist as a tree surgeon who is a professional both educated and experienced in the practice of arboriculture, which is the study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.

Understanding proper tree care and forest management is an investment in safety for the community and the vitality of our forests. And, having a team of certified professional arborists working with our crews is an invaluable resource in the post-fire resource assessment and felling of hazard trees. Because arborists specialize in the care of individual trees and forests, they are knowledgeable about the needs of trees and are trained to properly assess the health of a fire-damaged tree. This clean-up and rebuild effort in areas with forests and trees could not effectively take place without the assistance and guidance of professional and certified arborists.

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All certified arborists must include a professional resume for an International Society of Arboriculture (“ISA”) certified arborist verifying five years arborist experience in post-forest fire assessments in northwest United States Conifer forests along with mixed deciduous tree stands for tree health and stability and demonstrated understanding of forest management practices.

In some cases, the arborists may be a professional forester who have the same experience qualifications as the certified arborist. A number of professional foresters come from the pacific northwest with significant timber cruising and health assessment experiences.

A certified arborist or professional forester will perform an assessment of all trees in the impacted area and identify those trees which pose a hazard and must be removed. The objectives of the tree assessment and inventory will include:

• Identification of all trees damaged by the incident,

• Assessment of the damage and survivability to each tree,

• Assessment of each tree against established indicators of hazardous tree criterion, and

• Determination which trees should be removed during recovery efforts conducted by the consultant.
  

Hazard tree criteria

Certified arborists follow FEMA criteria to determine if a tree is a “hazard tree.” Hazard trees are dead or dying trees that will present an eminent threat to the traveling public within a five year timeframe.

The FEMA description that we follow for hazard tree marking includes: “If the tree’s condition is caused by the disaster; is an immediate threat to lives/public health/safety/property; the tree has a diameter of six inches or more 4.5 feet above ground level; and has one or more of these criteria: --crown more than 50% damaged or destroyed; --the trunk is split; --broken branches or exposed hardwood; --or it is leaning at an angle greater than 30 degrees. This also includes a distance of 1.5x their height, up to 2x their height.