Certified Arborist Test Tree Pruning Principles 2

Question 1

What is the branch protection zone (BPZ) and why is it critical to identify before making a pruning cut?

Accepted Answer

The zone of chemically and anatomically distinct tissue at the branch base that resists decay spread

Answer

The area of bark between the branch collar and the branch union that must be left undamaged

Answer

The ring of cambium at the cut surface that initiates woundwood formation after pruning

Answer

The innermost layer of heartwood that protects the parent stem from decay entry

Question 2

What is the recommended sequence of cuts when removing a large limb to prevent bark tearing?

Accepted Answer

Undercut first to prevent bark stripping, then top cut, then final cut just outside branch collar

Answer

One smooth cut made just outside the branch collar from top to bottom in a single pass

Answer

Remove the limb in sections from the tip toward the trunk, making the final cut at the collar

Answer

Make a notch cut at 45 degrees from the top, then a back cut from the bottom to meet it

Question 3

What is the primary purpose of crown raising, and what is the minimum acceptable live crown ratio after raising?

Accepted Answer

Removing lower branches to provide clearance — maintaining at least 40-60% live crown ratio for tree health

Answer

Reducing wind resistance to prevent storm damage — minimum 25% live crown ratio

Answer

Balancing the crown after storm damage — no minimum ratio applies as structural integrity is the priority

Answer

Improving aesthetic form — maintaining at least 30% live crown ratio is sufficient for all species

Question 4

What distinguishes 'topping' from proper reduction pruning, and why is topping considered harmful?

Accepted Answer

Topping cuts branches back to stubs or laterals too small to assume the terminal role; proper reduction maintains lateral size ratios

Answer

Topping removes dead wood; reduction pruning removes live wood — neither is harmful when done correctly

Answer

Topping is performed only on conifers; reduction pruning is for broadleaf trees exclusively

Answer

Topping means removing only the top 10% of crown volume; reduction pruning removes up to 25%

Question 5

When is wound dressing (pruning paint/sealant) recommended after pruning cuts, according to current ISA guidelines?

Accepted Answer

After pruning cuts on oak trees to prevent nitidulid beetle vectors of oak wilt from entering fresh cuts

Answer

After all pruning cuts larger than 2 inches in diameter to prevent decay entry

Answer

After all pruning cuts on young trees to promote faster woundwood closure

Answer

After any cut made during summer to prevent moisture loss from the exposed wood surface

Question 6

What is epicormic sprouting and what typically causes it after pruning?

Accepted Answer

Sprouts that emerge from dormant or adventitious buds on stems or trunk in response to stress or sudden light exposure

Answer

New terminal growth that extends from intact branch tips after crown thinning removes competing branches

Answer

Root suckers that grow from the root system following heavy crown pruning

Answer

Hormone-induced growth from the cut surfaces of properly made pruning wounds