CATS Pruning Standards and Cuts 2 — Questions and Answers
Question 1: What is the primary reason to avoid leaving a stub when removing a branch?
- It looks unsightly to clients
- It prevents formation of wound wood and leads to decay (Correct answer)
- It makes future pruning harder
- It increases water sprout production
Correct answer: It prevents formation of wound wood and leads to decay
Stubs block the tree's natural closure process, allowing decay fungi to colonize the dead tissue before wound wood can form.
Question 2: According to ANSI A300 standards, which pruning type removes live branches to reduce overall tree size while maintaining form?
- Crown cleaning
- Crown raising
- Crown reduction (Correct answer)
- Crown restoration
Correct answer: Crown reduction
Crown reduction decreases the height or spread of a tree by cutting back to lateral branches large enough to assume the terminal role.
Question 3: When making a reduction cut, the lateral branch retained should be at least what fraction of the diameter of the removed branch?
- One-quarter
- One-third (Correct answer)
- One-half
- Two-thirds
Correct answer: One-third
ANSI A300 recommends the retained lateral be at least one-third the diameter of the cut stem to sustain adequate photosynthate flow and avoid dieback.
Question 4: Which term describes removing only dead, dying, diseased, or weakly attached branches from the crown?
- Crown thinning
- Crown cleaning (Correct answer)
- Crown lifting
- Deadwooding
Correct answer: Crown cleaning
Crown cleaning specifically targets the removal of defective wood and is the most common pruning type recommended for mature trees.
Question 5: A flush cut that removes the branch collar is problematic because it:
- Creates too large an entry wound for decay
- Removes the zone of tissue richest in defensive chemicals
- Both increases wound size and removes the defensive zone (Correct answer)
- Stimulates excessive epicormic growth
Correct answer: Both increases wound size and removes the defensive zone
The branch collar contains both the trunk's protective chemical barrier zone and the tissue needed for wound closure, so removing it enlarges the wound and defeats tree defenses simultaneously.
Question 6: The three-cut method for removing heavy branches prevents:
- Formation of water sprouts
- Bark tearing caused by the weight of a falling limb (Correct answer)
- Excessive wounding of the branch collar
- Spread of canker diseases
Correct answer: Bark tearing caused by the weight of a falling limb
The undercut and relief cut together remove most of the branch weight before the final collar cut, preventing gravity from stripping bark down the trunk.
Question 7: Which pruning practice is classified as a lion-tailing and is discouraged by ANSI A300?
- Removing all live branches from the inner crown and leaving foliage only at branch tips (Correct answer)
- Thinning the upper canopy to admit more light to understory plants
- Removing co-dominant stems from young trees
- Pruning trees during active insect transmission periods
Correct answer: Removing all live branches from the inner crown and leaving foliage only at branch tips
Lion-tailing strips inner foliage and creates long, weakly-tapered limbs prone to failure under wind and ice loads.
CATS Pruning Standards and Cuts 2
What is the primary reason to avoid leaving a stub when removing a branch?