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Risk Evaluation & Mitigation 

Our team of Certified Arborists has extensive training and experience asessing the risk trees may present. Our early studies of tree anatomy were conducted by splitting hundreds of cords of firewood from numerous tree species by hand, without the use of mechanized equipment. Further knowledge of tree structure was gained through three decades of climbing, pruning, removing trees along with observations of hundreds of failed tree remnants.


JPA has gained both Certified and Qualified Tree Risk Assessor designations from the International Society of Arboriculture (ISA) and Pacific Northwest (PNW) Chapter ISA. Workshops presented by Dr. Alex Shigo, Clauss Matheck and Dr. Kevin Smith provided scientific knowledge of tree anatomy and physiology.

Our protocol for assessing tree risk adheres to ISA Best Management Practices and the American National Standards Institute A-300. This is a sytematic process designed to identify, analyze and evaluate tree risk. It must be undersood that this process differs from a Hazard Tree Assessment since a hazard refers to the part(s) of a tree that are structurally weak, otherwise damaged or may have the potential to fall. Risk is defined as the combination of the likelihood of an event and the severity of the consequences-personal injury,  property damage or disruption of activities. (Adapted from Tree Risk Assessment Manual, ISA 2013)


JPA can conduct one of three Levels of inspection; Limited Visual, Basic and Advanced. Advanced Levels of analysis can include the use of dignostic equipment including  Airspade, IML Resistograph and/or Arbotom, a sonic tomograph the measures the speed of stress waves to determine wood strength. JPA has owned, operated and interpreted findings.

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