Certified Arborist Practice Exam 2026 - Free Certified Arborist Practice Questions and Study Guide

The correct understanding of support systems highlights that an adjustable support system allows for modifications based on the tree's growth or environmental conditions.

In this context, "adjustable" refers to the capability of certain support mechanisms to be altered over time as the tree develops or as circumstances change. This would typically include systems like cables or braces that can be tightened or loosened as necessary.

Conversely, the option labeled as false indicates a lack of adjustability, which is not characteristic of many effective support systems used in tree care. Additionally, thimbles, while used in conjunction with ropes or cables, are passive components and are not themselves adjustable. Plant growth regulators serve to influence growth rates but do not act as support systems. Lastly, the mention of J-hooks relates to installation conditions and does not concern the general concept of adjustability in support systems for trees. Therefore, the true characteristic of an adjustable support system is essential for the proper management and safety of trees.