Introduction to Tree Risk Assessment

Question 1

an interference between the needs of a tree and society or infrastructure

Answer 1

Tree conflict

Question 2

an organized and systematic examination

Answer 2

Inspection

Question 3

the highest level of risk that does not exceed the owner/manager’s tolerance

Answer 3

Acceptable Risk Threshold

Question 4

the likelihood of a conflict or tree failure occurring and affecting a target, and the severity of the associated consequences

Answer 4

Risk

Question 5

a systematic process used to identify, analyze, and evaluate tree risk

Answer 5

Tree Risk Assessment

Question 6

the process of comparing the assessed risk against given risk criteria to determine the significance of the risk

Answer 6

Tree Risk Evaluation

Question 7

the application of policies, procedures, and practices used to identify, evaluate, mitigate, monitor, and communicate tree risk.

Answer 7

Tree Risk Management

Question 8

people, property, or activities that could be injured, damaged, or disrupted by a tree failure.

Answer 8

Target

Question 9

breakage of stem, branch, or roots, or loss mechanical support in the root system.

Answer 9

Failure

Question 10

personal injury or death, property damage, or disruption of activities

Answer 10

Harm

Question 11

the chance of tree failure occurring and/or impacting a specified target

Answer 11

Likelihood

Question 12

outcome of an event

Answer 12

Consequences

Question 13

the tree part(s) identified as a likely source of harm

Answer 13

Hazard

Question 14

a process to estimate numerical probability values for consequences and to calculate numeric values for risk.

Answer 14

Quantitative Risk Assessment

Question 15

a process using ratings of consequences and likelihood to determine risk significance levels and to evaluate the level of risk

Answer 15

Qualitative Risk Assessment

Question 16

restraints or factors that restrict the precision, applicability, or extent of something.

Answer 16

Limitations

Question 17

the defined project objectives and requirements

Answer 17

Scope of work

Question 18

The scope of work should include specifications for the following:

Answer 18

1) Tree(s) or area to be assessed
2) Level and details of the assessment
3) Method of reporting
4) Timetable for inspection and reporting
5) Risk rating and mitigation

Question 19

time period for which an assessment is defined.

Answer 19

Time frame

Question 20

the body of moral principles or values governing a group or individual’s conduct.

Answer 20

Ethics

Question 21

something for which one is responsible

Answer 21

Liability

Question 22

a principle or rule established by a prior court or other decision-making body

Answer 22

Legal precedents

Question 23

legal obligation that requires an individual to apply reasonable actions when performing tasks that may potentially harm others.

Answer 23

Duty of care

Question 24

failure to take reasonable care to avoid injury or damage to a person or property in a situation where the law imposes a duty of care.

Answer 24

Breach of duty

Question 25

failure to use reasonable care, resulting in damage or injury to another.

Answer 25

Negligence

Question 26

degree of care that a reasonable person should exercise in performing duty of care; a measurement used to assess whether an individual acted in a reasonable manner

Answer 26

Standard of care

Question 27

True/False

The tree risk assessor determines the acceptable risk threshold.

Answer 27

False

Question 28

True/False
When balancing tree risks and benefits, it is important to remember that the risk trees pose to human safety is extremely low.

Answer 28

True

Question 29

A tree risk assessor is free of risk while inspecting trees because mitigation measures have yet to be taken.

Answer 29

False

Question 30

A large tree leaning over a busy intersection and a bus stop might be evaluated as having severe __________, should the tree fail, because of the potential to injure people and damage property.

Answer 30

consequences

Question 31

A __________ tree risk assessment often uses ratings combined in a matrix to evaluate the risk, whereas a __________ tree risk assessment produces a numeric value based on probabilities and consequences.

Answer 31

qualitative

quantitative

Question 32

Prior to performing a tree risk assessment, it is important to work with the tree owner/manager to define the __________.

Answer 32

scope of work

Question 33

Tree structural __________ are commonly caused by a combination of structural defects or conditions, such as the presence of decay or poor structure, and an unusual or extreme loading event.

Answer 33

failures

Question 34

A tree risk assessor must use the generally accepted __________ when evaluating tree risk or s/he might be found negligent in a court.

Answer 34

standard of care

Question 35

The process of identifying trees, assessing them for risk, determining and applying mitigation options, and maintaining an ongoing monitoring system is referred to as

A) tree risk assessment
B) tree risk management
C) inspection protocol
D) tree evaluation protocol

Answer 35

B) tree risk management

Question 36

It is impossible to maintain trees free of risk because

A) trees are living organisms and naturally lose branches or fall
B) tree maintenance budgets are too limited for risk mitigation
C) there aren’t enough arborists to assess all risks
D) not all practices can be applied in the same way to all trees

Answer 36

A) trees are living organisms and naturally lose branches or fall

Question 37

Because tree risk assessors may perform risk assessments with limited information about tree and site conditions, the assessment is

A) invalid due to high levels of uncertainty
B) mostly dependent on the target occupancy rate
C) mostly dependent on the target value
D) founded on observations, experience, and training

Answer 37

D) founded on observations, experience, and training

Question 38

The scope of work should clarify

A) any property boundaries that restrict access to the tree(s)
B) local government or authority’s requirements for inspection and permitting
C) to whom the final report is to be submitted
D) all of the above

Answer 38

D) all of the above

Question 39

Standard of care is measured by using

A) the best management practices, applicable industry standards, and training courses
B) the laws that are enforced by city ordinances
C) the level of care deemed reasonable by the tree owner/manager
D) all of the above

Answer 39

A) the best management practices, applicable industry standards, and training courses