ISA Certified Arborist Practice Exam 2025 - Free ISA Arborist Practice Questions and Study Guide

Improper planting depth significantly affects tree survival primarily through its impact on root development and overall tree health. When a tree is planted too deep, the root system does not have the opportunity to grow properly; this often leads to poorly developed roots that may not anchor the tree securely or effectively gather water and nutrients from the soil.

Shallow planting can expose the root flare, which is the area where the trunk transitions into the root system. If this area becomes buried, it can lead to girdling roots, where roots grow around the trunk instead of spreading outward. This inhibits normal growth and can stress the tree, making it more vulnerable to diseases and pests.

Additionally, trees planted too deep may struggle with poor aeration, which can lead to root rot and other health issues, further compromising the tree's chance of survival. The inability to develop a strong root system ultimately contributes to a tree’s susceptibility to environmental stressors, making it a critical factor in tree management and successful planting practices.