Tree Risk Assessment Practice Questions

Correct answer: B. The tree owner or manager

A risk assessor estimates the likelihood and consequences of failure and recommends options, but the tree owner or manager (for public land, the responsible official) decides what level of risk to accept and what work, if any, to do. The assessor is the tempting choice because they rate the risk, yet rating a risk and accepting it are separate roles. Work crews carry out decisions rather than make them, and an insurer does not manage the tree.

• A: The assessor evaluates the risk and recommends options but does not set the owner's risk tolerance.
• C: The crew carries out the chosen work; it does not decide what risk is acceptable.
• D: The owner or manager, not an insurer, is responsible for managing the tree.

Sources: Tree Risk Assessment Methods: A Comparison of Three Common Evaluation Forms (ENH1226), UF/IFAS Extension (EDIS) ; Field Guide for Hazard-Tree Identification and Mitigation on Developed Sites in Oregon and Washington Forests (R6-NR-TP-021-2013), USDA Forest Service, Pacific Northwest Region (GovInfo)

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Correct answer: A. Identifying high risk and then taking no action can be treated as negligence

The USDA guide says high-risk trees must be dealt with as soon as possible after they are identified, and that a community may be assumed negligent if it finds high risk and then does nothing. It also states that not having funds does not relieve a community of its responsibility in lawsuits. The guide adds that a community proves it took reasonable care by producing records that show its trees were not just inspected but that hazardous ones were corrected in a timely manner, so a file of known, uncorrected high-risk trees does not protect the city.

• B: A record of known, uncorrected high risk works against the city rather than protecting it.
• C: The guide puts the duty to act on the community that identified the risk, not on the inspector who rated the trees.
• D: The guide states that not having funds does not absolve a community of responsibility.

Sources: Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry ; Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry ; Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry

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Correct answer: A. Decayed or severed main support roots

Main support roots anchor the entire tree, so when they are dead, decayed or missing, the whole tree can tip over or collapse in a strong wind. UF/IFAS advises having such a tree inspected for the risk of collapse. A dead branch, a hanging broken branch and a weak branch union are serious defects, but each usually leads to failure of that part of the tree rather than the whole tree.

• B: A dead branch typically fails on its own while the rest of the tree stays standing.
• C: A hanging branch is a part failure already under way, not a whole-tree failure.
• D: A weak scaffold union usually fails by splitting off that branch, not by uprooting the tree.

Source: Is My Tree Safe? Recognizing Conditions that Increase the Likelihood of Tree Failure (ENH1246), UF/IFAS Extension

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Correct answer: D. Treat it as a public-safety risk and prune the limbs for clearance

Tree risk is not limited to structural failure. The USDA Forest Service guide counts trees that visually block intersections, traffic signs or street lighting among the public-safety risks a program should reduce, and it directs crews to remove branches that obstruct signs, signals or lighting or that limit drivers' view of approaching traffic. A sound tree can still create a serious risk by hiding a stop sign, so calling it no risk or waiting for decay misses the problem.

• A: A tree can create a traffic risk without any structural defect.
• B: Clearance pruning of trees that block signs is part of the tree risk program's work.
• C: The risk comes from the blocked view now, not from future decay.

Sources: Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry ; Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry

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Correct answer: B. Level 1 (limited visual) assessment of the population

A Level 1 limited visual assessment, sometimes done as a walk-by or drive-by, is most common where trees are abundant and inspection resources are scarce, and it is used to find high-risk trees that are mitigation priorities. Alabama Extension notes that street trees often get Level 1 assessments for preliminary screening. Level 2 and Level 3 assessments take far more time per tree and are better reserved for individual trees flagged during screening or for high-value trees.

• A: Advanced assessments are costly and reserved for specific trees or questions, not whole populations.
• C: A basic assessment of every tree takes far more time than a screening needs.
• D: Root collar excavation is a detailed technique used on individual trees.

Sources: Tree Risk Assessment Methods: A Comparison of Three Common Evaluation Forms (ENH1226), UF/IFAS Extension (EDIS) ; Spotting Danger: How to Identify & Assess Hazard Trees (FOR-2175), Alabama Cooperative Extension System

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Correct answer: A. Little or none, because no target is within reach of a failure

Risk requires a target that a failed tree or part could strike. Alabama Extension notes that a tree cannot be counted as a hazard if no potential target exists, and a USDA Forest Service field guide states that a defective tree is not a hazard tree when it has no target. The dead limb makes failure likely, which is why 'high' is tempting, but with no people or property in reach the risk is negligible. That changes if a trail or bench is later added nearby.

• B: Likelihood of failure is high, but risk also needs a target within reach.
• C: No defect makes risk extreme when there is nothing to strike.
• D: Risk ratings depend on targets and consequences, not only on the presence of a defect.

Sources: Spotting Danger: How to Identify & Assess Hazard Trees (FOR-2175), Alabama Cooperative Extension System ; Field Guide for Hazard-Tree Identification and Mitigation on Developed Sites in Oregon and Washington Forests (R6-NR-TP-021-2013), USDA Forest Service, Pacific Northwest Region (GovInfo)

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Correct answer: D. Not necessarily; crown vigor does not show structural soundness

Confusing crown vigor with structural soundness is a common inspection error. Vigor reflects energy supply from the thin layers of cambium and sapwood, so a tree can look healthy while its stem wood, branch attachments or anchoring roots are badly decayed or damaged. Soundness has to be judged by examining those parts directly. Normal fall color or a lack of dead branches does not rule out structural defects either.

• A: A healthy crown can sit on a decayed trunk or damaged roots.
• B: Early fall color is a health symptom; normal color does not prove structural soundness.
• C: Serious defects such as internal decay or cracks often occur without dead branches.

Sources: Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry ; Urban Tree Risk Management: A Community Guide to Program Design and Implementation (NA-TP-03-03), USDA Forest Service, Northeastern Area State and Private Forestry

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Correct answer: C. A tree that began leaning in last week's storm, with heaved soil

A lean that forms suddenly, such as during a storm, indicates partial root failure and needs immediate attention, especially when the soil is heaving or cracking at the base. Trees with long-standing leans usually compensate: the lower trunk enlarges and the top or branches turn upward, and a USDA Forest Service guide calls a corrected lean a sign of a strong root system. Stable, long-term leans still deserve monitoring, but they are not the emergency here.

• A: An upturned top on an old lean shows the tree has compensated and is likely stable.
• B: A thickened lower trunk is compensating growth typical of a long-term lean.
• D: A lean that has not changed in decades is far less urgent than a new one.

Sources: Is My Tree Safe? Recognizing Conditions that Increase the Likelihood of Tree Failure (ENH1246), UF/IFAS Extension ; Hazard Trees in Alaska: A Guide to the Identification and Management of Hazard Trees in Alaska (R10-TP-142), USDA Forest Service, Alaska Region (GovInfo)

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Correct answer: B. Move the bench out of reach, checking trees at its new spot

Moving the target is a quick, low-cost way to reduce risk while the tree work waits. UF/IFAS notes that lowering risk may require nothing more than moving a potential target such as a bench, and a USDA Forest Service guide adds that the trees around the target's new location must then be examined so it is not placed under another defective tree. A sign leaves people in the strike zone. Cabling is no quick answer either: the Alaska guide uses cable supports only as a last resort, and UF/IFAS warns that a dead limb is bound to drop eventually. A limb that has not fallen yet can still fail at any time, even in milder weather.

• A: A sign does not move people out of the strike zone; the risk remains while people sit there.
• C: UF/IFAS warns that a dead limb is bound to drop eventually, and the Alaska guide uses cable supports only as a last resort.
• D: A dead, cracked limb can fail at any time, with or without a storm.

Sources: Is My Tree Safe? Recognizing Conditions that Increase the Likelihood of Tree Failure (ENH1246), UF/IFAS Extension ; Hazard Trees in Alaska: A Guide to the Identification and Management of Hazard Trees in Alaska (R10-TP-142), USDA Forest Service, Alaska Region (GovInfo)

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Correct answer: A. The level of risk found at the initial inspection

Purdue Extension states that the interval between inspections depends on the risk level found at the initial inspection, with the tree's age, growing conditions and other factors also affecting frequency. Trees with a history of failures or problem structure should be monitored more often, and all trees should be checked after major weather events. A single fixed interval for every tree ignores these differences, and trunk size or recent pruning alone does not set the schedule.

• B: Intervals should vary with the risk found; one fixed cycle over-inspects some trees and neglects others.
• C: Size matters to consequences, but the interval is set mainly by the risk found.
• D: Recent pruning alone does not determine how soon a tree must be rechecked.

Sources: Tree Defect Identification (FNR-614-W), Purdue Extension ; Tree Risk Management (FNR-475-W), Purdue Extension

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