ISA ARBORIST EXAM STUDY GUIDE 191 2026
FULL QUESTIONS WITH ANSWERS GRADED A+
◉ What applies to stump grinders? Answer: Local underground
utilities need to be located prior to grinding.
◉ Which of the following is a macronutrient? Answer: Calcium.
◉ What is the first step when planting a tree? Answer: Calling Dig-
Safe or JULIE to locate underground utilities.
◉ What are tannins and allelochemicals examples of? Answer:
Natural defense mechanisms.
◉ When is topping trees allowed? Answer: Only during vista
pruning.
◉ When is it appropriate to amend native soil with organic
materials? Answer: When the native soil is heavily compacted or
lacks organic matter.
,◉ What happens when an arborist touches a branch resting on a
powerline? Answer: The arborist is in direct contact with the power
line.
◉ How do mycorrhizae help trees? Answer: By increasing their
ability to absorb nutrients, such as phosphorus.
◉ What does the 30/20/10 guideline refer to? Answer: No more
than 30% of a family; 20% of a genus; 10% of a species.
◉ What is the most impactful method of applying compost and
biochar? Answer: Soil renovation.
◉ What should a job briefing include? Answer: Site hazards,
obstacles, required PPE, and equipment.
◉ What can a soil analysis determine prior to planting? Answer:
Nutrient levels.
◉ What could result in a poor safety culture? Answer: Encouraging
workers to cut pieces smaller and/or sharing lifting loads over 50
pounds.
, ◉ What does an effective risk management program do? Answer:
Identifies and assesses risk.
◉ What is a system for interweaving branches horizontally called?
Answer: Pleaching.
◉ What should be recorded during tree risk assessments? Answer:
Defects of significance.
◉ What is a benefit of pruning trees during dormancy? Answer: Can
allow the tree to make the most of the growing season.
◉ What should scaffold branches be like when selecting planting
stock? Answer: Distributed evenly around the trunk.
◉ What factors are required for photosynthesis? Answer: Light,
water, CO2, chlorophyll, and essential minerals.
◉ What does the acronym TDS stand for? Answer: The process a
worker goes through prior to using a knot or hitch.
◉ What determines minimum approach distances for utility line-
clearance pruning? Answer: Nominal voltages of the charged wire.
FULL QUESTIONS WITH ANSWERS GRADED A+
◉ What applies to stump grinders? Answer: Local underground
utilities need to be located prior to grinding.
◉ Which of the following is a macronutrient? Answer: Calcium.
◉ What is the first step when planting a tree? Answer: Calling Dig-
Safe or JULIE to locate underground utilities.
◉ What are tannins and allelochemicals examples of? Answer:
Natural defense mechanisms.
◉ When is topping trees allowed? Answer: Only during vista
pruning.
◉ When is it appropriate to amend native soil with organic
materials? Answer: When the native soil is heavily compacted or
lacks organic matter.
,◉ What happens when an arborist touches a branch resting on a
powerline? Answer: The arborist is in direct contact with the power
line.
◉ How do mycorrhizae help trees? Answer: By increasing their
ability to absorb nutrients, such as phosphorus.
◉ What does the 30/20/10 guideline refer to? Answer: No more
than 30% of a family; 20% of a genus; 10% of a species.
◉ What is the most impactful method of applying compost and
biochar? Answer: Soil renovation.
◉ What should a job briefing include? Answer: Site hazards,
obstacles, required PPE, and equipment.
◉ What can a soil analysis determine prior to planting? Answer:
Nutrient levels.
◉ What could result in a poor safety culture? Answer: Encouraging
workers to cut pieces smaller and/or sharing lifting loads over 50
pounds.
, ◉ What does an effective risk management program do? Answer:
Identifies and assesses risk.
◉ What is a system for interweaving branches horizontally called?
Answer: Pleaching.
◉ What should be recorded during tree risk assessments? Answer:
Defects of significance.
◉ What is a benefit of pruning trees during dormancy? Answer: Can
allow the tree to make the most of the growing season.
◉ What should scaffold branches be like when selecting planting
stock? Answer: Distributed evenly around the trunk.
◉ What factors are required for photosynthesis? Answer: Light,
water, CO2, chlorophyll, and essential minerals.
◉ What does the acronym TDS stand for? Answer: The process a
worker goes through prior to using a knot or hitch.
◉ What determines minimum approach distances for utility line-
clearance pruning? Answer: Nominal voltages of the charged wire.
