What a professional arborist report actually contains.
The phrase “arborist report” covers everything from a one page form to a hundred page expert disclosure. Here is what to expect from a consulting grade report: ours, and any other you commission.
Seven things to look for.
If any of these are missing from a report you have received, that is worth a question. If most are missing, that is worth a second opinion.
- 01
Scope and methodology
What was inspected, what was not, and the standard or method used (TRAQ, CTLA, ANSI A300, ISA BMP, etc.), stated explicitly so the report can be evaluated on its own terms.
- 02
Site and tree description
Property context, species, dimensions (DBH, height, crown spread), and condition class for each tree in scope.
- 03
Observations of fact
Defects, decay, deadwood, codominant unions, included bark, root collar conditions, prior wounds, pest or pathogen signs, recorded as observations, not conclusions.
- 04
Analysis
How the observations were interpreted in light of the methodology: likelihood of failure reasoning, target analysis, decay extent estimates, or appraisal calculations as applicable.
- 05
Opinions and recommendations
Identified as opinions, with the basis for each clearly shown. Mitigation, treatment, monitoring intervals, or removal recommendations are tiered where appropriate so the client can choose.
- 06
Photographic documentation
Labeled, dated photographs keyed to the text. For risk assessment and appraisal work, photos preserve evidence as found on the date of inspection.
- 07
Limitations and assumptions
What the report does and does not cover, any access limitations, and the conditions under which the conclusions hold. This is what separates a defensible report from a marketing document.
Still have a question?
If your question is not here, or if you want to know whether what you are facing actually needs an arborist, we are happy to talk.