Tree Pruning Practices Flashcards

What is a 'target cut' and when is it used in tree pruning?

Answer: The final precision cut of the three-cut method, made at the target location just outside the branch bark ridge and branch collar

The target cut is the final, carefully placed cut in the three-cut pruning sequence. It is made at the precise location where the branch collar and branch bark ridge indicate the boundary of the branch attachment, ensuring optimal wound closure.

How does pruning affect a tree's root-to-shoot ratio and why does this matter?

Answer: Removing live crown reduces the shoot component, temporarily increasing the root-to-shoot ratio, which reduces carbohydrate supply to roots and may trigger compensatory above-ground growth

Removing foliage through pruning reduces photosynthetic capacity and the crown's demand for water and nutrients, shifting the root-to-shoot ratio. The tree responds by redirecting growth to restore its species-specific equilibrium, often producing vigorous regrowth.

What is 'pollarding' and how does it differ from topping?

Answer: Pollarding is a historical pruning system initiated on young trees, creating permanent 'knuckles' from which new growth is annually or biennially harvested, while topping is the inappropriate reduction of established trees through random heading cuts

Pollarding is an intentional, culturally significant management system started when trees are young, creating predictable regrowth points (pollard heads or knuckles). Topping is the destructive practice of cutting established trees to stubs without regard to proper technique or long-term management.

What biosecurity measures should arborists take when pruning trees affected by or at risk for certain transmissible diseases?

Answer: Disinfect cutting tools between trees using 70% isopropyl alcohol, 10% bleach solution, or other approved disinfectants; clean equipment; and properly dispose of infected material

When pruning trees with transmissible diseases (fire blight, Dutch elm disease, oak wilt), tools must be disinfected between cuts or between trees. Infected material should be disposed of properly (not chipped on site), and equipment should be cleaned to prevent spreading pathogens.

Why is it important to consider the species-specific wound closure rate when planning pruning on mature trees?

Answer: Species with slow wound closure rates (like oaks and conifers) are exposed to decay organisms for longer periods, so minimizing wound size through proper technique and timing is even more critical for these species

Species vary significantly in wound closure rates. Slow-closing species have longer exposure of wood to decay organisms, making proper technique (small wounds, preserving the branch collar) and timing especially important to minimize decay risk.

How does proper pruning technique change when working on trees with brittle wood, such as silver maple or Bradford pear?

Answer: Extra care must be taken with the three-cut method to prevent uncontrolled splitting, branch weight should be reduced in smaller sections, and structural pruning in youth is especially important to prevent codominant stems

Trees with brittle wood require modified technique: smaller sections to control weight during removal, careful three-cut execution because the wood splits easily, and — most importantly — thorough structural pruning when young to prevent the codominant stems and tight crotches that are especially failure-prone in brittle species.