Certified Arborist Tree Risk — Questions and Answers

Question 1: Which risk assessment method is regarded as the minimum standard?

Visual assessment of trees (Correct answer)
Excavation of the root collar
Inspection of the aerial canopy
Testing for decay

Correct answer: Visual assessment of trees

A basic visual assessment of trees is considered the minimum standard for identifying potential hazards and assessing tree risk. This initial evaluation involves observing the tree's overall health, structure, and surroundings from the ground. More detailed methods like excavation or decay testing are advanced assessments performed when specific concerns are identified during the visual inspection.

Question 2: The most common sources of tree problems are:

Pathogens
Insects
Mites
Adverse environmental conditions (Correct answer)

Correct answer: Adverse environmental conditions

While pathogens, insects, and mites can certainly cause tree problems, adverse environmental conditions are the most pervasive and common source of stress and decline for trees. Factors like drought, extreme temperatures, poor soil quality, compaction, improper planting, and pollution weaken trees, making them more susceptible to pests and diseases. Addressing environmental stressors is crucial for tree health.

Question 3: Why is having a good taper important for a stem?

When a force is applied to a stem, it breaks less frequently if the taper is good. (Correct answer)
A stem that has a good taper may produce more fruit.
For insects, a well-tapered stem makes a sturdy perch.
A well-tapered stem enhances its ability to absorb nutrients.

Correct answer: When a force is applied to a stem, it breaks less frequently if the taper is good.

Taper refers to the gradual reduction in diameter of a tree stem or branch from its base to its tip. A good taper indicates strong structural integrity, allowing the stem to better withstand forces like wind and snow without breaking. This natural design distributes stress more effectively, contributing to the tree's overall stability and resilience.

Question 4: What is the proper way to adjust the hinge on a tree with a particularly large diameter?

The hinge should be larger.
The hinge should be deeper.
The hinge should be smaller. (Correct answer)
No adjustment needed.

Correct answer: The hinge should be smaller.

When felling a tree, the hinge wood is crucial for controlling the tree's direction of fall. For trees with a large diameter, a smaller hinge is generally recommended to prevent the hinge from tearing prematurely or holding the tree too rigidly, which could lead to uncontrolled or unpredictable felling. A smaller, well-formed hinge provides better control and a cleaner break.

Question 5: When lightning strikes a tree, which of the following factors DOES NOT affect the extent of the damage?

Wood porosity
Bark thickness
Moisture content
Leaf thickness (Correct answer)

Correct answer: Leaf thickness

When lightning strikes a tree, the electrical current travels through the tree, often vaporizing moisture and causing explosive damage. Factors like wood porosity (how easily electricity can travel through it), bark thickness (which can offer some insulation), and moisture content (which conducts electricity) significantly influence the extent of damage. Leaf thickness, however, has negligible impact on how lightning interacts with and damages the tree's main structure.

Question 6: What is a naturally occurring event that could not be foreseen or prevented in legal terms?

A liable act
An inevitable act
An act of God (Correct answer)
An act of interest

Correct answer: An act of God

In legal contexts, an 'act of God' refers to an unforeseeable natural phenomenon that is beyond human control and for which no one can be held responsible. This term is often used in contracts and insurance policies to describe events like hurricanes, earthquakes, or lightning strikes, which can excuse parties from liability or performance.

Question 7: Early fall color on a tree most typically indicates that there are issues with:

The tree’s roots. (Correct answer)
The tree’s trunk.
The tree’s crown
The tree’s scaffold branches.

Correct answer: The tree’s roots.

Early fall color is a common symptom of stress in trees, and root problems are frequently the underlying cause. Damaged, diseased, or compromised roots struggle to absorb water and nutrients, leading to premature senescence (aging) of leaves and early color change. This can be due to drought, soil compaction, root rot, or physical damage.

Question 8: Which of these is a typical cause of chronic stress?

Early frost
Fire
Poor drainage (Correct answer)
Lightning

Correct answer: Poor drainage

Chronic stress refers to long-term, ongoing stressors that gradually weaken a tree over time. Poor drainage leads to waterlogged soil, depriving roots of oxygen and causing root rot, which is a persistent problem. In contrast, early frost, fire, and lightning are acute stressors, meaning they are sudden, severe events that cause immediate damage rather than prolonged decline.

Question 9: When is the ideal time to spray trees with micronutrients?

When evening falls
Early in the winter season
Shortly following transplantation
Just prior to the time of rapid growth (Correct answer)

Correct answer: Just prior to the time of rapid growth

The ideal time to apply micronutrients via foliar spray is typically just before or during the period of rapid new growth in spring. At this time, leaves are emerging and actively photosynthesizing, making them most receptive to absorbing nutrients through their stomata. Applying micronutrients during this phase ensures they are available when the tree has the highest demand for growth.

Question 10: Which of the following determines the risk of trees?

The girdling roots' presence. (Correct answer)
The soil's pH levels.
The popularity of tree species in landscaping.
The status of the arborist certification.

Correct answer: The girdling roots' presence.

Girdling roots grow around the trunk or other roots, constricting the flow of water and nutrients, and weakening the tree's structural integrity. This can lead to reduced stability, branch dieback, and increased susceptibility to pests and diseases, significantly elevating the risk of tree failure. Therefore, identifying girdling roots is crucial for assessing a tree's risk.

Question 11: What part does degradation play in determining the risk to trees?

It lessens the tree's risk of failure.
It elevates the tree's risk of failure. (Correct answer)
Only the aesthetic value is impacted.
it does not affect the tree’s stability.

Correct answer: It elevates the tree's risk of failure.

Degradation, such as decay, rot, or structural damage, directly compromises a tree's strength and stability. As wood degrades, it loses its ability to support the tree's weight and withstand environmental stresses like wind, making the tree more prone to breaking or falling. Therefore, degradation significantly increases the risk of tree failure.

Certified Arborist Tree Risk

Which risk assessment method is regarded as the minimum standard?