CATS Pruning Standards and Cuts 3 — Questions and Answers
Question 1: Which cut is recommended when removing a branch that has formed a distinct branch collar?
- Flush cut just outside the collar
- Cut just outside the branch bark ridge and collar (Correct answer)
- Cut halfway between the collar and the branch midpoint
- Cut at the branch midpoint to balance weight
Correct answer: Cut just outside the branch bark ridge and collar
The correct cut follows the angle set by the branch bark ridge on top and stays just outside the collar on the bottom to preserve the tree's natural wound-closure tissues.
Question 2: What is the main objective of crown thinning?
- Reduce overall tree height
- Remove all interior dead wood
- Increase light penetration and air movement through the canopy (Correct answer)
- Eliminate co-dominant leaders
Correct answer: Increase light penetration and air movement through the canopy
Crown thinning selectively removes branches throughout the canopy to improve light and air circulation without significantly changing the tree's overall size.
Question 3: In young tree structural pruning, selecting a dominant central leader typically involves:
- Removing all lateral branches below the first scaffold whorl
- Subordinating competing co-dominant stems by reducing or removing them (Correct answer)
- Topping the tree to force lateral growth
- Removing the terminal bud to encourage branching
Correct answer: Subordinating competing co-dominant stems by reducing or removing them
Subordination pruning reduces the length of competing stems relative to the selected leader, directing energy to the dominant stem.
Question 4: The branch bark ridge (BBR) is important because it:
- Marks where the final pruning cut angle should begin on the upper side (Correct answer)
- Indicates the presence of included bark
- Shows where the branch begins to die back
- Defines the outer edge of the branch collar on the lower side
Correct answer: Marks where the final pruning cut angle should begin on the upper side
The BBR is a raised ridge of bark at the top of the branch union that guides the upper angle of the proper pruning cut.
Question 5: When pruning oaks in Albuquerque to reduce risk of oak wilt transmission, what timing practice is recommended?
- Prune only during full leaf-out in summer
- Avoid pruning during spring when sap-feeding beetles are most active (Correct answer)
- Prune only in winter when temperatures are below freezing
- Prune in early spring before bud break to maximize wound closure time
Correct answer: Avoid pruning during spring when sap-feeding beetles are most active
Nitidulid beetles that vector oak wilt fungus are most active during spring sap flow, so pruning wounds made then are highly attractive to these vectors.
Question 6: Which statement about wound dressings and pruning paint is consistent with current arboricultural research?
- They speed wound closure by protecting cambium tissue
- They reduce decay by sealing out fungal spores
- They are generally not recommended and do not improve wound closure or prevent decay (Correct answer)
- They should be applied to all cuts larger than 2 inches in diameter
Correct answer: They are generally not recommended and do not improve wound closure or prevent decay
Research has shown wound dressings do not accelerate compartmentalization or prevent decay and can in some cases trap moisture and promote rot.
Question 7: A 'heading cut' differs from a 'thinning cut' in that a heading cut:
- Removes a branch at its point of origin on the parent stem
- Cuts a branch back to a stub or small lateral not large enough to assume dominance (Correct answer)
- Reduces the crown spread back to a codominant lateral
- Removes only dead or dying tissue
Correct answer: Cuts a branch back to a stub or small lateral not large enough to assume dominance
Heading cuts terminate a branch at an arbitrary point or to a small lateral, often stimulating vigorous but weakly attached epicormic growth just below the cut.
CATS Pruning Standards and Cuts 3
Which cut is recommended when removing a branch that has formed a distinct branch collar?