CTSP Hazard and Risk Assessment 2 — Questions and Answers
Question 1: When assessing a tree near a target, which factor MOST directly determines risk magnitude?
- Tree species and age
- Likelihood of failure multiplied by consequences (Correct answer)
- Distance from the target to the tree
- Time of year the inspection occurs
Correct answer: Likelihood of failure multiplied by consequences
Risk magnitude is determined by multiplying the likelihood of failure by the consequences if failure occurs.
Question 2: A tree arborist notices a co-dominant stem with included bark. Which term best describes this structural defect?
- Basal decay
- Weak attachment (Correct answer)
- Crown dieback
- Epicormic growth
Correct answer: Weak attachment
Included bark between co-dominant stems creates a weak attachment point that significantly increases failure potential.
Question 3: Which inspection method is most appropriate for detecting internal decay that is not visible externally?
- Visual crown assessment
- Resistograph or sonic tomography (Correct answer)
- Increment boring only
- Bark color evaluation
Correct answer: Resistograph or sonic tomography
Instruments like the Resistograph and sonic tomography can detect internal decay columns not apparent during visual inspection.
Question 4: A large dead branch over a playground is identified. According to ANSI A300 Part 9, what is the appropriate risk category when likelihood of failure is high and consequences are severe?
- Low risk
- Moderate risk
- High risk
- Extreme risk (Correct answer)
Correct answer: Extreme risk
High likelihood of failure combined with severe consequences (occupied target) places a hazard in the Extreme risk category.
Question 5: Which of the following site conditions increases the likelihood of tree failure during a wind event?
- Deep, well-drained loam soil
- Saturated soil with shallow root plate (Correct answer)
- South-facing slope with full sun
- Compacted gravel under the drip line
Correct answer: Saturated soil with shallow root plate
Saturated soil weakens root anchorage, making trees far more susceptible to windthrow during storms.
Question 6: What does the term 'target' refer to in a tree risk assessment?
- The specific branch most likely to fail
- People, property, or activities that could be injured or damaged (Correct answer)
- The zone where pruning cuts should be made
- The primary pest or disease affecting the tree
Correct answer: People, property, or activities that could be injured or damaged
A target is any person, vehicle, structure, or activity that would be harmed if a tree or tree part failed and struck it.
Question 7: An arborist observes carpenter ant activity at the base of an otherwise healthy-looking tree. What should be the next assessment step?
- Immediately remove the tree
- Probe and sound the base for internal decay (Correct answer)
- Apply a systemic insecticide
- Document and re-inspect in one year
Correct answer: Probe and sound the base for internal decay
Carpenter ants nest in decayed wood, so their presence signals potential internal decay requiring further probing and sounding.
CTSP Hazard and Risk Assessment 2
When assessing a tree near a target, which factor MOST directly determines risk magnitude?