Certified Arborist Practice Exam

Which of the following is NOT a mechanical injury commonly inflicted on trees?

1. Lawnmower

2. Weed-eater

3. Construction

4. Pruning

The correct answer is: Pruning

Pruning is an essential and routine part of tree care aimed at promoting health, structure, and aesthetics. Unlike mechanical injuries, which are often unintentional damage inflicted by equipment or activities, pruning is a deliberate action taken to remove specific branches or limbs. In contrast, lawnmowers and weed-eaters can cause unintentional injuries to a tree's bark and roots if they come into contact with them. Construction activities often disturb the root zone of trees, which can harm their health and stability. Thus, pruning is not classified as a mechanical injury, as it is a method used to enhance the tree's growth and wellbeing, rather than causing harm.