ISA Certified Arborist Practice Exam 2025 – All-in-One Resource for Comprehensive Exam Success!

Regular pruning of dead branches is a vital practice for maintaining tree health. Removing dead, damaged, or diseased branches promotes better air circulation and sunlight penetration within the tree's canopy, which is essential for photosynthesis and overall vitality. By eliminating these problematic branches, you also reduce the risk of infection or infestation that can spread to healthy parts of the tree.

Additionally, proper pruning helps to shape the tree and encourages strong structural growth. It can foster better limb development, reducing the likelihood of branch failure during storms or high winds. This practice also contributes to aesthetics, ensuring that the tree maintains an appealing form and structure.

In contrast, other practices listed may undermine tree health. For instance, over-fertilizing the soil can lead to nutrient imbalance and root burn, while watering only during drought may not provide adequate hydration for the tree's needs throughout its growth cycle. Planting trees too close together can result in competition for resources, leading to stunted growth and increased vulnerability to pests and diseases.