Certified Arborist Test Pruning Principles and Practices Questions and Answers — Questions and Answers
Question 1: An arborist is performing structural pruning on a young maple tree. They identify two codominant stems of roughly equal size forming a 'V' shaped union with included bark. According to best practices, what is the most appropriate action to take?
- Remove one of the stems completely back to the trunk.
- Shorten one of the stems using a reduction cut, subordinating it to the other. (Correct answer)
- Leave both stems to develop naturally, as the tree will self-correct.
- Install a cable between the two stems to provide support.
Correct answer: Shorten one of the stems using a reduction cut, subordinating it to the other.
Subordination is the preferred method for correcting codominant stems in young trees. By shortening one stem with a reduction cut, its growth is slowed, allowing the other to become the dominant leader. This gradually corrects the structural flaw without creating a large wound from complete removal, which can be stressful for a young tree. Cabling is generally reserved for mature trees where removal or reduction is not feasible.
Question 2: When making a proper final pruning cut to remove a lateral branch from a trunk, the cut should be made just outside the branch collar and branch bark ridge. What is the primary reason for preserving the branch collar?
- It contains dormant buds that will sprout new branches.
- It provides mechanical support to the branch being removed.
- It contains a zone of specialized tissue that helps compartmentalize decay. (Correct answer)
- It is primarily composed of phloem and carries sugars to the branch.
Correct answer: It contains a zone of specialized tissue that helps compartmentalize decay.
The branch collar is a swollen area at the base of a branch that contains overlapping trunk and branch tissues. Crucially, it includes a branch protection zone with specialized cells that initiate compartmentalization, walling off the pruning wound from the trunk and inhibiting the spread of decay. Damaging or removing the collar compromises this defense mechanism.
Question 3: A client asks an arborist to significantly reduce the height of a mature sweetgum tree that has grown too large for its location. The client suggests 'topping' the tree. Which of the following is the most significant negative consequence of topping?
- It permanently stops the tree from growing any taller.
- It immediately improves the tree's structural integrity.
- It leads to the growth of weakly attached, vigorous watersprouts. (Correct answer)
- It reduces the tree's water requirements by more than 50%.
Correct answer: It leads to the growth of weakly attached, vigorous watersprouts.
Topping, the indiscriminate cutting of branches to stubs, creates large wounds and removes a significant portion of the tree's canopy. The tree responds by producing numerous, fast-growing shoots (watersprouts) just below the cuts. These sprouts are weakly attached to the decaying stubs and are prone to failure as they grow, creating a more hazardous situation than before.
Question 4: Which of the following pruning objectives specifically involves the removal of dead, diseased, dying, or broken branches?
- Crown raising
- Crown thinning
- Crown cleaning (Correct answer)
- Crown reduction
Correct answer: Crown cleaning
Crown cleaning is defined as the selective removal of dead, dying, diseased, and broken branches. This is a fundamental type of pruning to improve tree health, safety, and appearance. Crown thinning reduces density, crown raising provides vertical clearance, and crown reduction decreases the overall size of the crown.
Question 5: According to ANSI A300 standards, what is the general maximum percentage of live foliage that should be removed from a mature, healthy tree in a single year?
- 10%
- 50%
- 75%
- 25% (Correct answer)
Correct answer: 25%
The ANSI A300 pruning standards, which are the industry-accepted guidelines for tree care, recommend that no more than 25 percent of a tree's foliage should be removed in a single year. This limit helps prevent stressing the tree, which can lead to reduced vigor, increased susceptibility to pests and diseases, or the production of excessive watersprouts. For stressed or older trees, the amount should be even less.
Question 6: A client wants to prune a large oak tree in mid-autumn because the leaves are falling and the branch structure is visible. Why is this generally considered a poor time to prune most deciduous trees?
- The tree is actively transporting nutrients to the branches.
- Pruning at this time encourages vigorous new growth before winter.
- Wound closure is slow as the tree enters dormancy, increasing decay potential. (Correct answer)
- Insects and pathogens are most active during the fall.
Correct answer: Wound closure is slow as the tree enters dormancy, increasing decay potential.
Pruning in the fall is generally discouraged because the tree is preparing for dormancy and wound closure is slow. The ideal time for pruning most deciduous trees is late winter or early spring, just before the new growth starts. At that time, wound closure happens most rapidly, minimizing the opportunity for decay organisms to enter the pruning cuts.
Certified Arborist Test Pruning Principles and Practices Questions and Answers
An arborist is performing structural pruning on a young maple tree.
They identify two codominant stems of roughly equal size forming a 'V' shaped union with included bark.
According to best practices, what is the most appropriate action to take?