FREE ISA Tree Risk Assessment Questions and Answers

Question 1

An arborist performs a Level 2 Basic Tree Risk Assessment on a mature oak in a public park. This level of assessment primarily involves which of the following activities?

Accepted Answer

A 360-degree, ground-based visual inspection of the tree's roots, trunk, and crown, potentially using simple tools like a mallet or probe.

Answer

A rapid, drive-by visual survey to identify only trees with imminent failure potential.

Answer

Advanced diagnostic procedures such as sonic tomography or resistance drilling to quantify internal decay.

Answer

A comprehensive analysis of historical aerial photographs and soil survey maps for the site.

Question 2

In the context of the ISA Tree Risk Assessment methodology, what are the three principal components that are analyzed to determine the overall risk rating of a tree?

Accepted Answer

Likelihood of failure, likelihood of impacting a target, and the consequences of impact.

Answer

Tree species, age, and height.

Answer

Soil type, site hydrology, and pest presence.

Answer

Pruning history, fertilization schedule, and owner's risk tolerance.

Question 3

A TRAQ-qualified arborist is assessing a tree with a significant cavity at its base. The tree is located in a remote, rarely visited section of a large forest preserve with no trails or structures nearby. How does the absence of a target affect the overall risk rating?

Accepted Answer

It significantly lowers the risk rating, as risk requires a combination of a failing tree part and a target to be impacted.

Answer

It increases the risk rating because the tree is unmanaged.

Answer

It does not affect the risk rating; the presence of a defect is the only factor.

Answer

It mandates an immediate Level 3 assessment regardless of other factors.

Question 4

Which of the following is considered a risk mitigation option that does NOT involve pruning or removing the tree?

Accepted Answer

Moving a picnic table away from the tree's fall zone.

Answer

Crown reduction.

Answer

Cabling and bracing.

Answer

Subordination of codominant stems.

Question 5

During a site assessment for a tree risk evaluation, an arborist notes the tree is on a steep slope with evidence of recent soil erosion and is fully exposed to prevailing high winds. These observations are most critical for evaluating the:

Accepted Answer

Likelihood of failure.

Answer

Consequences of failure.

Answer

Owner's risk tolerance.

Answer

Tree's historical significance.

Question 6

An arborist needs to perform an advanced assessment to gather more detailed information about the internal structure of a high-value veteran tree after a basic assessment identified a potential area of significant decay. Which of the following methods corresponds to a Level 3 Advanced Assessment?

Accepted Answer

Employing sonic tomography to create a cross-sectional map of wood density.

Answer

A walk-by survey of the tree from a single vantage point.

Answer

A 360-degree visual inspection from the ground using binoculars.

Answer

Using a rubber mallet to sound the trunk for hollows.