Arborist
Also called: certified arborist, tree surgeon, ISA arborist
A tree-care professional trained in the biology, health, and safe removal of trees. 'ISA Certified Arborist' is the recognized credential, issued by the International Society of Arboriculture after an exam and experience requirement.
Not everyone who cuts down trees is an arborist. Many tree services are staffed by skilled climbers and sawyers without formal certification, and that’s fine for a straightforward removal. An arborist’s added value is judgment: whether a tree actually needs to come down, whether it can be saved with pruning or cabling, and how to remove it without damaging neighboring trees or the site.
Hire an arborist — or a company with one on staff — when the decision itself is in question, when the tree is a protected species or in a permit zone (many cities require an arborist’s report), or for large, high-value trees near structures.
To verify a credential, search the ISA directory by name or location.