CTSP Hazard and Risk Assessment 5 — Questions and Answers
Question 1: A mature tree displays reaction wood (tension wood in hardwoods) on one side of the trunk. What does this indicate about the tree's history?
- The tree has been regularly pruned and is healthy
- The tree has compensated for a lean or mechanical stress over time (Correct answer)
- The tree suffered a single lightning strike
- The tree was recently transplanted and is establishing
Correct answer: The tree has compensated for a lean or mechanical stress over time
Reaction wood forms as a tree compensates for a persistent lean or mechanical stress, indicating the tree has experienced or adapted to gravitational or wind loading.
Question 2: Which of the following is an example of a PRIMARY failure mode in tree risk assessment?
- A branch falling after being severed by a chainsaw
- Whole tree windthrow due to root decay (Correct answer)
- A branch being broken by a falling neighboring tree
- Lightning strike causing crown failure
Correct answer: Whole tree windthrow due to root decay
Whole tree windthrow caused by root decay is a primary failure mode, meaning the tree fails due to its own structural deficiency rather than an external force.
Question 3: What does a 'likelihood of impact' rating consider when the target is an occupied parking lot open 10 hours per day?
- Only the vehicle type typically parked there
- The probability that a person or vehicle would be in the failure zone when failure occurs (Correct answer)
- The number of cars parked per year aggregated over the tree's life
- The proximity of the lot to the nearest emergency room
Correct answer: The probability that a person or vehicle would be in the failure zone when failure occurs
Likelihood of impact estimates the probability that a target will be present in the failure zone at the moment of failure, considering occupancy patterns.
Question 4: An arborist inspects a tree and notes significant dieback in the upper crown with epicormic sprouting lower on the trunk. Which condition does this pattern typically suggest?
- Normal seasonal growth flush
- Decline or chronic stress causing energy redirection to lower sprouts (Correct answer)
- Successful recovery from a pruning wound
- Pest infestation limited to the crown only
Correct answer: Decline or chronic stress causing energy redirection to lower sprouts
Upper crown dieback combined with lower epicormic sprouting is a classic sign of tree decline, where the tree redirects limited energy closer to the root system.
Question 5: Under the ANSI A300 Part 9 standard, who is qualified to perform an advanced-level tree risk assessment?
- Any landowner who has read tree care guidelines
- A qualified arborist with documented training in tree risk assessment (Correct answer)
- Any licensed contractor performing site clearing
- A municipal inspector with general construction experience
Correct answer: A qualified arborist with documented training in tree risk assessment
ANSI A300 Part 9 requires that advanced risk assessments be performed by a qualified arborist who has documented training such as ISA TRAQ certification.
Question 6: Which of the following mitigation options is most appropriate when tree removal is undesirable but the risk from a specific large branch is high?
- Applying wound paint to all pruning cuts
- Crown reduction pruning or structural cabling of the defective branch (Correct answer)
- Injecting systemic fungicide at the root zone
- Fertilizing to stimulate rapid new growth
Correct answer: Crown reduction pruning or structural cabling of the defective branch
Crown reduction pruning reduces the load on the defective branch, and structural cabling provides supplemental support, both lowering failure likelihood without removing the tree.
Question 7: A property owner asks why a seemingly solid-looking tree was flagged as high risk. Which explanation best addresses the limitation of external appearance?
- External appearance always matches internal condition in mature trees
- Significant internal decay can be fully concealed by intact bark and a healthy crown (Correct answer)
- A healthy crown guarantees a sound root system and trunk
- Risk assessment focuses only on branch failures, not the trunk
Correct answer: Significant internal decay can be fully concealed by intact bark and a healthy crown
Trees can harbor extensive internal decay that is completely hidden by intact bark, making visual appearance an unreliable indicator of internal structural condition.
CTSP Hazard and Risk Assessment 5
A mature tree displays reaction wood (tension wood in hardwoods) on one side of the trunk.
What does this indicate about the tree's history?