What Does a Consulting Arborist Do? | Arborist On Demand

By Matthew T. Latham, BCMA, RCA, TPAQ
ISA Board Certified Master Arborist | ASCA Registered Consulting Arborist

When most people hear the word arborist, they picture some crazy guy climbing & pruning trees, operating a bucket truck, or removing a hazardous tree.

That is certainly part of arboriculture, but it is not what every arborist does.

A consulting arborist is hired primarily for professional knowledge, investigation, analysis, and recommendations. Rather than simply asking “What work should we perform on this tree?”, a consulting arborist may be asked:

Why did this tree or limb fail?
Was there evidence of a defect before the failure?
What is a damaged or destroyed tree worth?
Can this tree reasonably be preserved during construction?
Did a storm cause the damage, or were pre-existing conditions involved?
Does the tree present an unacceptable level of risk?
What does the available physical evidence actually support?

These questions become especially important when trees are involved in insurance claims, lawsuits, property disputes, construction projects, tree appraisals, or questions of public safety.

What Is a Consulting Arborist?

A consulting arborist is an arboricultural professional who provides technical opinions, documentation, analysis, and recommendations concerning trees and landscapes.

Arboriculture simply means the science and practice of establishing, managing, and caring for individual trees and other woody plants.

The distinction between consulting and contracting is important.

A tree service is generally hired to perform work on a tree. A consulting arborist is hired primarily to evaluate the situation and provide professional guidance about it.

Sometimes those roles overlap. However, independence can be particularly valuable when an arborist is being asked whether a tree should be removed, whether damage can be repaired, what caused a failure, or what a tree is worth.

The end product may be an inspection, professional opinion, written report, tree appraisal, risk assessment, preservation plan, expert testimony, or a combination of these.

Specialized diagnostic testing, including sonic tomography, can provide additional information about the internal condition of a tree when visual inspection alone does not answer the question.

What Does a Consulting Arborist Actually Do?

Consulting arboriculture covers a surprisingly broad range of work. My assignments commonly involve some combination of tree diagnosis, forensic investigation, tree and plant appraisal, risk assessment, construction-related tree preservation, insurance claims, and litigation support.

The common denominator is evidence.

My role as a consultant is not to begin with the conclusion a client wants. It is to evaluate the available information and determine what conclusions that information reasonably supports.

Forensic Tree Investigations

Some assignments fall within forensic arboriculture.

Forensic simply means applying specialized knowledge to investigate questions that may involve a loss, dispute, insurance claim, or legal proceeding.

For example, after a tree failure I may evaluate the remaining tree or stump, fracture characteristics, decay, root system, previous pruning, site conditions, photographs, maintenance history, weather information, and other available evidence.

One important part of forensic work is separating an observation from a conclusion.

Observation: Decay was present within the failed branch union.
Conclusion: The decay materially contributed to the failure.

The first can be directly documented. The second requires professional analysis of the available evidence.

That distinction becomes particularly important when a report may ultimately be reviewed by an insurance carrier, attorney, engineer, opposing expert, or court.

Detailed photographic documentation can preserve information concerning location, orientation, tree condition, and physical evidence observed during an investigation.

Advanced Tree Diagnostics

Not every tree problem can be diagnosed by looking at the leaves.

A consulting arborist may evaluate the trunk, scaffold limbs, branch unions, root flare, rooting environment, soil conditions, canopy structure, previous pruning, decay indicators, and site history.

When necessary, additional diagnostic tools may be used.

Sonic tomography, for example, is a nondestructive testing technique that measures how sound waves travel through a tree. Those measurements can help identify variations within the wood that may warrant further evaluation.

The equipment does not simply declare a tree “safe” or “unsafe.”

Diagnostic results must be interpreted alongside the tree’s structure, species, observable defects, site conditions, and potential targets.

Tree Failure Analysis

A fallen tree does not automatically mean somebody was negligent.

Likewise, the presence of wind does not automatically establish that a storm was the sole cause of failure.

Tree failure often involves an interaction between load and structural capacity.

Load is the force being applied to the tree, such as wind acting upon the canopy.

Structural capacity is the tree’s ability to withstand those forces.

Decay, cracks, weak branch unions, compromised roots, previous damage, and other conditions may reduce that capacity.

A forensic arborist therefore attempts to reconstruct what occurred from the available evidence rather than simply identifying the most obvious event immediately preceding the failure.

Sometimes the evidence supports a strong conclusion.

Sometimes it does not.

Recognizing the difference is part of competent consulting.

Tree and Plant Appraisal

Trees can also have substantial monetary value.

A tree appraisal is a professional opinion of value or loss developed using an appropriate appraisal methodology and the available facts.

Appraisals may be needed following:

• unauthorized tree removal;
• vehicle or equipment impacts;
• construction damage;
• neighbor disputes;
• insurance losses;
• vandalism; or
• other property damage.

Tree appraisal is more complicated than simply assigning a dollar amount based upon trunk diameter.

Species, size, condition, location, contribution to the property, replacement feasibility, and the purpose of the appraisal may all become relevant.

A mature tree may also be substantially larger than anything realistically available for purchase and installation. That creates a different valuation problem than replacing a small ornamental tree readily available from a nursery.

Tree Risk Assessment

Consulting arborists are also frequently asked whether a tree is dangerous.

The better question is usually: What risk does this tree present under the circumstances being evaluated?

Tree risk assessment considers the likelihood of a tree or tree part failing, what could be struck if failure occurs, and the potential consequences.

A defective limb extending over an unused field presents a very different situation from a similar limb extending over an occupied structure.

Risk assessment therefore considers both the tree and its surroundings rather than evaluating a defect in isolation.

Trees and Construction

Construction can significantly affect mature trees even when the trunk is never touched.

Roots require adequate soil volume, oxygen, moisture, and physical space. Excavation, trenching, soil compaction, grade changes, root severance, equipment traffic, and changes in drainage can all affect the root environment.

Soil compaction occurs when soil particles are compressed together, reducing the pore spaces that normally contain air and water.

A consulting arborist involved before and during construction can help identify tree protection areas, document existing conditions, evaluate proposed impacts, and recommend reasonable preservation measures.

Successful tree preservation during construction requires protecting the below-ground environment, not merely placing a barrier around the trunk.

Insurance Claims, Subrogation, and Litigation

Trees frequently become part of property damage and casualty claims.

A tree may fall onto a home or vehicle. Construction may damage a valuable tree. A carrier may need to distinguish recent storm damage from a pre-existing condition.

A forensic arborist can evaluate the arboricultural questions involved in the loss.

This can also become important in subrogation, which occurs when an insurer that has paid a covered loss seeks recovery from another party that may be legally responsible.

The arborist does not determine legal liability.

Instead, the arborist evaluates technical questions within his or her expertise, such as tree condition, defects, failure characteristics, maintenance history, damage, and causation when the evidence permits.

In litigation, a consulting arborist may also review records, inspect physical evidence, prepare an expert report, participate in depositions, or provide expert testimony.

The objective remains the same:

Follow the evidence, even when the evidence does not support the answer someone expected.

When Should You Hire a Consulting Arborist?

A consulting arborist makes the most sense when you primarily need an independent professional opinion rather than tree work.

That may include a tree failure, insurance claim, significant property loss, construction project, tree appraisal, neighbor dispute, potential litigation, or another situation where the consequences of making the wrong decision are significant.

And not every case requires advanced testing or a lengthy report.

Not every defect requires tree removal.

Not every fallen tree indicates negligence.

Not every storm explains the entire failure.

Good consulting is about determining what the evidence actually supports.

Choosing the Right Consulting Arborist

Different tree-related assignments require different expertise.

Pruning a residential tree, valuing a significant landscape loss, developing a construction preservation plan, and reconstructing a serious tree failure are very different assignments.

For complex matters, consider the arborist’s:

• professional credentials and education;
• experience with the specific type of assignment;
• report-writing experience;
• familiarity with recognized arboricultural standards and best practices;
• appraisal qualifications when monetary value is involved; and
• forensic or litigation experience when a dispute may require expert testimony.

The question should not simply be “Are you an arborist?”

It should be:

“Does this arborist have the qualifications and experience appropriate for this particular problem?”

About the Author

Matthew T. Latham is an ISA Board Certified Master Arborist (TX-3737B), ASCA Registered Consulting Arborist (RCA #859), and Tree & Plant Appraisal Qualified professional.

Through Arborist On Demand, LLC, I provide independent consulting services involving forensic tree investigations, tree and landscape appraisal, insurance and subrogation matters, construction-related tree damage and preservation, tree risk, expert witness services, and litigation support.

Based in Houston, Texas. Consulting nationwide.

Need an Independent Consulting Arborist?

If you’re dealing with a tree-related insurance claim, property loss, construction issue, appraisal, failure investigation, or legal dispute, the first step is determining what question needs to be answered and what evidence is available to answer it.

Contact Arborist On Demand to discuss your assignment or schedule a consultation.