10.2 Targets and Occupancy
Key Takeaways
- A target is a person, property, activity, or infrastructure that could be affected by tree failure.
- Occupancy matters because a rarely used target area differs from a constantly occupied one.
- Target management can be a mitigation option when changing the tree is not the only practical response.
- The arborist should document target assumptions because site use can change after the assessment.
Finding What Could Be Struck
A target is anything of value that could be struck if a tree or tree part fails. Targets include people, homes, vehicles, roads, trails, benches, playgrounds, utilities, fences, signs, outdoor dining, and work zones. In exam scenarios, target analysis often changes the best answer. The visible defect may be the same, but the risk concern changes when the target changes.
Occupancy is the pattern of target presence. A sidewalk outside a school at dismissal has higher occupancy than a remote trail used once a month. A parking lot may be full during business hours and empty at night. A patio may be seasonal. The arborist should ask how the area is used, when it is used, and whether use could change after the report.
| Target condition | Risk meaning | Possible response |
|---|---|---|
| Constant occupancy | Failure is more likely to affect a target | Prioritize mitigation or access control. |
| Intermittent occupancy | Timing and use pattern matter | Consider scheduling, warnings, or pruning based on defect. |
| Rare occupancy | Consequence may be lower if no one is present | Document assumptions and monitor. |
| Moveable target | Risk can sometimes be reduced by relocation | Move bench, table, parked vehicles, or play equipment. |
| Fixed target | Tree work or structural/site mitigation may be needed | Protect building, path, utility, or road. |
| Changing site use | Current assessment may become stale | Recommend reassessment after use changes. |
Target management is sometimes the most practical mitigation. Moving a bench from under dead branches may reduce exposure quickly. Closing a trail during storms may reduce occupancy during high load. Redirecting pedestrian flow can reduce risk until pruning or other work is completed. The exam may include answers that focus only on the tree, but a target solution can be correct when it effectively reduces exposure.
The arborist must also avoid assuming an area is unused without evidence. A vacant lot may be crossed by children walking to school. A quiet courtyard may host events. A maintenance road may have daily workers. Good target analysis asks the owner, observes site cues, and documents assumptions.
Target Analysis Questions
- What person, property, activity, or infrastructure is within striking distance?
- How often is the target present?
- Is target presence predictable by time of day, season, weather, or event schedule?
- Can the target be moved, restricted, shielded, or redirected?
- Would target use change if the site is redeveloped, opened to the public, or temporarily occupied by workers?
- Are emergency access, utilities, or transportation corridors involved?
Scenario: A tree with a hanging broken limb stands over a picnic table. If the table can be moved immediately, moving it may reduce exposure while pruning is scheduled. If the table is fixed and used every day, prompt pruning or access restriction becomes more urgent. The target decision shapes the timeline.
Scenario: A cracked limb extends over a road. The target is not only vehicles but also pedestrians, cyclists, emergency responders, and property beyond the curb. Because occupancy may be frequent and consequences serious, the arborist should communicate urgency and may recommend restricting the area until mitigation is completed.
Target analysis also affects follow-up intervals. If a tree with a known defect is near a high-use playground, waiting a long time to reassess may be inappropriate. If a low-use area becomes a festival site, the old target assumptions no longer fit. The owner or manager needs to know that changing occupancy can change risk.
For the Certified Arborist exam, do not skip the target. A defect is important, but risk requires the combination of potential failure, target, and consequence. The best answer often identifies the target first, then chooses mitigation that reduces either failure potential or target exposure.
What is a target in tree risk assessment?
Why does occupancy matter when evaluating a target?
Which action is an example of target management?